50ff3ff2-ecd8-4f88-b84c-467c0a0101be-9756_p4_cons_en

Manual ofAircraft Accidentand Incident Investigation

First Edition — 2003

Doc 9756

AN/965

International Civil Aviation Organization

Part IV

Reporting

Approved by the Secretary Generaland published under his authority

Manual ofAircraft Accidentand Incident Investigation

First Edition — 2003

Doc 9756

AN/965

International Civil Aviation Organization

Part IVReporting

Approved by the Secretary Generaland published under his authority

AMENDMENTS

The issue of amendments is announced regularly in the ICAO Journal and in themonthly Supplement to the Catalogue of ICAO Publications and Audio-visualTraining Aids, which holders of this publication should consult. The space belowis provided to keep a record of such amendments.

RECORD OF AMENDMENTS AND CORRIGENDA

AMENDMENTS CORRIGENDA

No.Date

applicableDate

enteredEntered

by No.Date

of issueDate

enteredEntered

by

IV-(ii)

IV-(iii)

FOREWORD

The purpose of this manual is to encourage the uniformapplication of the Standards and Recommended Practicescontained in Annex 13 and to provide information andguidance to States on the procedures, practices andtechniques that can be used in aircraft accidentinvestigations. Since accident investigations vary incomplexity, a document of this kind cannot cover alleventualities. The more common techniques and processes,however, have been included. Although this manual will beof use to experienced and inexperienced investigators alike,it is not a substitute for investigation training andexperience.

This manual will be issued in four separate parts asfollows:

Part I — Organization and Planning;

Part II — Procedures and Checklists;

Part III — Investigation; and

Part IV — Reporting.

Because this manual deals with both accident andincident investigations and, for reasons of brevity, the terms“accidents” and “accident investigation”, as used herein,apply equally to “incidents” and “incident investigation”.

The following ICAO documents provide additionalinformation and guidance material on related subjects:

— Annex 13 — Aircraft Accident and IncidentInvestigation;

— Accident/Incident Reporting (ADREP) Manual(Doc 9156);

— Accident Prevention Manual (Doc 9422);— Manual of Civil Aviation Medicine (Doc 8984);— Human Factors Training Manual (Doc 9683);— Human Factors Digest No. 7 — Investigation of

Human Factors in Accidents and Incidents(Circular 240).

This manual, which supersedes Doc 6920 in its entirety,will be amended periodically as new investigationtechniques are developed and new information becomesavailable.

Readers are invited to submit material for possibleinclusion in subsequent editions of this manual. Thismaterial should be addressed to:

The Secretary GeneralInternational Civil Aviation Organization999 University StreetMontréal, QuebecCanada H3C 5H7

��

IV-(v)

TABLE OF CONTENTS

Page Page

Chapter 1. The Final Report . . . . . . . . . . . . . IV-1-1

1.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . IV-1-11.2 The group reports . . . . . . . . . . . . . . . . . IV-1-11.3 Format and content of the

Final Report . . . . . . . . . . . . . . . . . . . . . . IV-1-21.4 Consultation on the draft

Final Report . . . . . . . . . . . . . . . . . . . . . . IV-1-21.5 Release and distribution of the

Final Report . . . . . . . . . . . . . . . . . . . . . . IV-1-31.6 Final Reports to be included in the

ICAO Aircraft Accident Digest . . . . . . IV-1-31.7 Exchange of Final Reports

between States . . . . . . . . . . . . . . . . . . . . IV-1-31.8 ICAO address . . . . . . . . . . . . . . . . . . . . IV-1-4

Appendix 1 to Chapter 1 — Format and content of the Final Report . . . . . . . . . . . . . . . . . . . . . IV-1-5Appendix 2 to Chapter 1 — Report writing conventions . . . . . . . . . . . . . . . . . . . . IV-1-17

Appendix 3 to Chapter 1 — Symbols and abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . IV-1-20Appendix 4 to Chapter 1 — Aviation terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . IV-1-24Appendix 5 to Chapter 1 — Commonly used findings. . . . . . . . . . . . . . . . . . . . . . . . . . IV-1-27

Chapter 2. The Accident/Incident Data Reporting (ADREP) System . . . . . . . . . . . . . . . IV-2-1

2.1 Reports. . . . . . . . . . . . . . . . . . . . . . . . . . IV-2-12.2 ADREP information available to States IV-2-12.3 Data validity . . . . . . . . . . . . . . . . . . . . . IV-2-22.4 Preliminary Report

(ADREP Form P) . . . . . . . . . . . . . . . . . IV-2-22.5 Accident Data Report

(ADREP Form D) . . . . . . . . . . . . . . . . . IV-2-22.6 Incident Data Report

(ADREP Form D) . . . . . . . . . . . . . . . . . IV-2-22.7 Constraints on Incident Data Reports. . IV-2-3

Chapter 1

THE FINAL REPORT

1.1 GENERAL

1.1.1 The Final Report of an aircraft accidentinvestigation is the foundation for initiating the safetyactions which are necessary to prevent further accidentsfrom similar causes. Therefore, the Final Report on anaccident must establish in detail what happened, how ithappened and why it happened. The findings and the causesof the Final Report should lead to safety recommendationsso that appropriate preventive measures can be taken.

1.1.2 The Final Report should provide:

— a record of all the relevant facts (including anyconflicting evidence);

— an analysis of the relevant facts;

— conclusions in the form of findings and causes; and

— safety recommendations.

The findings and the causes of a Final Report should pointclearly to the safety issues that need to be addressed.

1.1.3 The Final Report is usually the report of theinvestigator-in-charge or the accident investigationauthority. The report should cover in detail all relevantaspects of the investigation. When the investigation of anaccident is organized by establishing specialized groups,each group chairperson should submit a written report tothe investigator-in-charge together with all supportingdocumentation and data covering the facts and findingsestablished. The Final Report will be drafted based, to alarge extent, on the reports of the various groups. Theinvestigator-in-charge is responsible for ensuring that theFinal Report is written in a consistent and uniform style.

1.1.4 The investigation of a general aviation accidentseldom requires organization into groups. Suchinvestigations are usually carried out by one or two

investigators. As in the case of a major investigation, theresponsibility for the completeness and quality of the FinalReport rests with the investigator-in-charge and theaccident investigation authority.

1.2 THE GROUP REPORTS

In consultation with the group members, the groupchairperson is responsible for scrutinizing the evidencegathered in relation to the tasks assigned to the group, andfor drafting a group report, which presents all the factsrelevant to the activities of the group. Also, the groupchairperson should draft an analysis of the facts which thegroup has established, draft the findings of the group’sinvestigation and make proposals for safety recommen-dations. A group report should be presented in thefollowing format:

Introduction

This section gives brief identification details of the accidentand lists the names, titles and affiliations of the groupmembers. Matters of organization, such as the forming ofsub-groups to handle specific tasks within the terms ofreference of the group, should be explained. For example,in the case of the Operations Group, sub-groups such as aWitness Group and a Performance Group are sometimesformed. The terms of reference for the group and sub-groups and brief details of the time and location ofinvestigation activities should also be recorded in thissection.

Investigation

The facts, conditions and circumstances established by thegroup should be presented under appropriate headingsdescribing the areas investigated. For example, in the case

IV-1-1

IV-1-2 Manual of Aircraft Accident and Incident Investigation

of the Operations Group, headings would include crewhistories, flight planning, dispatch, and aircraft mass andbalance. All the relevant facts, whether or not consideredsignificant to the findings of the group, must be included.Relevant documentation should be attached to the groupreport.

Analysis

The analysis discusses the significance of the facts stated inthe previous section of the group report and presents thegroup’s analysis of those facts as they pertain to the termsof reference of the group. This information should bepresented in a logical way that leads to and supports thefindings.

Conclusions

The conclusions section of the group report should containthe substantiated findings of the group’s investigation. Anindication of the findings of the group which are consideredto be factors in the accident will assist the investigator-in-charge in the drafting of the Final Report.

Safety recommendations

The group report should include information on any safetyissues established, safety actions already taken, andproposals for safety recommendations.

1.3 FORMAT AND CONTENT OFTHE FINAL REPORT

1.3.1 An investigation into an aircraft accident is notcomplete until all the relevant facts revealed by theinvestigation, the analysis of the facts, the conclusions andthe safety recommendations have been recorded in theFinal Report. The Final Report should be structuredlogically and written in clear and concise language. Thereport should explain what happened, how it happened, andwhy the accident happened, and it should address the safetyissues involved. A standardized format of the Final Reportassists in the production of a complete and reliable recordof the investigation of the accident.

1.3.2 In a major investigation, the investigator-in-charge receives the group reports and is responsible for the

development and the drafting of the Final Report. The FinalReport should be a comprehensive report of the wholeinvestigation. The factual information collected during theinvestigation should form the basis for the analysis sectionof the report, which leads to and supports the establishmentof the findings, causes and safety recommendations. Thestandardized format for the Final Report, which iscontained in the Appendix to Annex 13, provides a well-structured record of the investigation. The Final Reportcontains five parts: Introduction (Title and Synopsis),Factual Information, Analysis, Conclusions (Findings andCauses) and Safety Recommendations.

1.3.3 Detailed guidance on the format and content ofthe Final Report is at Appendix 1 to Chapter 1.

1.3.4 For the reporting on small investigationsconducted by one or two investigators, some States havefound that the completion of an accident report form hassome advantages over drafting a full Final Report. Detailedinformation can easily be recorded by completing theappropriate sections of an accident report form. Narrativesare usually restricted to particular sections, such as ananalysis of the events leading to the accident, conclusionsand safety recommendations. The forms are designed toreduce the time required for recording the work ofinvestigators. The forms can also be used as a type ofinvestigation checklist. It is important that the accidentreport forms be consistent with the format of the FinalReport, to the extent possible, since this facilitates readercomprehension and any subsequent electronic accidentreporting.

1.4 CONSULTATION ON THEDRAFT FINAL REPORT

1.4.1 In accordance with Annex 13, the Stateconducting the investigation shall send a copy of the draftFinal Report to the State which instituted the investigationand to all States that participated in the investigation,inviting their significant and substantiated comments on thereport. The State conducting the investigation should alsosend copies of the draft Final Report to the operator and theorganizations responsible for type design and finalassembly of the aircraft, through the State of the Operator,the State of Design and the State of Manufacture,respectively, in order to enable the operator and suchorganizations to submit comments on the draft FinalReport. When sending the draft Final Report to recipientStates, the State conducting the investigation should

Part IV. ReportingChapter 1. The Final Report IV-1-3

consider using the most appropriate means available, suchas facsimile, e-mail, courier service or express mail. Whenthe draft Final Report is sent by e-mail, secure protectionshould be used when available.

1.4.2 If the State conducting the investigation receivescomments within sixty days of the date of the transmittalletter, it shall either amend the draft Final Report to includethe substance of the comments received or, if desired by theState that provided the comments, append the comments tothe Final Report. Usually, comments to be appended to theFinal Report are restricted to non-editorial specifictechnical aspects of the Final Report upon which noagreement could be reached.

1.4.3 States shall not circulate, release or give accessto a draft report or any part thereof, any group reports orany other investigation documentation obtained during aninvestigation of an accident, without the express consent ofthe State which conducted the investigation, unless suchreports or documents have already been published orreleased by that latter State.

1.5 RELEASE AND DISTRIBUTION OF THEFINAL REPORT

1.5.1 If the State conducting the investigation receivesno comments within sixty days, it shall issue the FinalReport, unless an extension of that period has been agreedby the States concerned. The State conducting theinvestigation should release the Final Report in the shortestpossible time, and if possible, within twelve months of thedate of the occurrence. If the report cannot be releasedwithin twelve months, the State conducting the inves-tigation should release an interim report or should use someother means detailing the progress of the investigation andany safety issues identified.

1.5.2 In addition to the release and distribution of theFinal Report within the State, the State conducting theinvestigation shall send the Final Report with a minimumof delay to:

a) the State which instituted the investigation;

b) the State of Registry;

c) the State of the Operator;

d) the State of Design;

e) the State of Manufacture;

f) any State having suffered fatalities or seriousinjuries to its citizens; and

g) any State which provided relevant information,significant facilities or experts.

1.6 FINAL REPORTS TO BE INCLUDEDIN THE ICAO AIRCRAFT

ACCIDENT DIGEST

1.6.1 The purpose of the ICAO Aircraft AccidentDigest is to disseminate information to States on selectedmajor accidents. Publication of the Digest began in 1951.States have reiterated a need for the Digest, not only as avaluable source for information on major accidents, butalso as a tool for accident prevention, as a training aid forinvestigators and as educational material for technicalschools.

1.6.2 When a Final Report has been released by aState that has conducted an investigation into an accident oran incident involving an aircraft of a maximum mass ofover 5 700 kg, that State shall send to ICAO a copy of theFinal Report. Whenever practicable, the Final Report sentto ICAO is to be prepared in one of the working languagesof ICAO, and in the format shown in the Appendix toAnnex 13.

1.6.3 The Final Reports included in the Digest areselected on the basis of their contribution to accidentprevention and are usually published as received. However,lengthy reports may be abbreviated and the appendices areusually not reproduced.

1.7 EXCHANGE OF FINAL REPORTSBETWEEN STATES

1.7.1 Aircraft accident prevention is dependent, inpart, on information made available from accidentinvestigations. The causes of accidents, especially those inwhich large aircraft are involved, are of interest to all Statesand in particular to those States operating similar aircrafttypes. Therefore, prompt dissemination to all States of thefindings of aircraft accident investigations can be a majorcontribution to aviation safety. To facilitate the exchange ofaccident information, all States are encouraged todisseminate their Final Reports to other States. Use of theInternet can expedite such dissemination.


1.7.2 ICAO also encourages States to exchangeinformation concerning any interim safety recommen-dations made before the completion of the Final Report.

1.7.3 The Accident/Incident Data Reporting(ADREP) Summary provides States with information onaccidents and incidents. However, the information in theADREP Summary is brief and States that require moredetailed information should request a copy of the FinalReport from the accident investigation authority in the Statewhich conducted the investigation. A list of addresses andweb sites of accident investigation authorities is containedin Appendix 2 to Chapter 4 of Part I of this Manual.

1.8 ICAO ADDRESS

In accordance with the provisions of Annex 13, acopy of the Final Report shall be sent to ICAO andaddressed:

International Civil Aviation OrganizationAttention: AIG999 University StreetMontréal, Quebec, Canada H3C 5H7

For electronic copies, the e-mail address is“[email protected]”.


Appendix 1 to Chapter 1FORMAT AND CONTENT OF THE FINAL REPORT

To enable the Final Report to be presented in a convenientand uniform manner, a standardized format is contained inthe Appendix to Annex 13. Detailed guidance oncompleting each section of the Final Report is providedbelow.

INTRODUCTION (Title and Synopsis)

The title of the Final Report should contain the followinginformation: name of the operator; manufacturer, model,nationality and registration marks of the aircraft; and placeand date of the accident.

The introduction should contain brief information on thenotification of the accident to national and foreignauthorities, the identification of the accident investigationauthority conducting the investigation, the accreditedrepresentation from other States and brief information onthe organization of the investigation. The authorityreleasing the report, as well as the date of release, shouldalso be given.

The introduction should contain a synopsis which brieflydescribes the accident. It should provide an overview of theaccident flight, a statement of why the accident happenedand a brief summary of the injuries and damage. Thesynopsis could be described as an executive summary ofthe Final Report and should usually not exceed one page inlength.

The title page, or the inside cover, may contain a statementon the accident prevention objective of the investigationand the Final Report. It may also be stated that it is not thepurpose of the investigation and the Final Report toapportion blame or liability. For example, the followingtext may be considered: “In accordance with Annex 13 tothe Convention on International Civil Aviation, it is not thepurpose of aircraft accident investigation to apportionblame or liability. The sole objective of the investigationand the Final Report is the prevention of accidents andincidents.”

The introduction may also contain a statement regardingthe responsibility for implementing the safety recommen-dations. For example, the following text may beconsidered: “Unless otherwise indicated, recommendations

in this report are addressed to the regulatory authorities ofthe State having responsibility for the matters with whichthe recommendation is concerned. It is for those authoritiesto decide what action is taken.”

The introduction should contain a reference to the time ofday used in the report, and the differential between localtime and Co-ordinated Universal Time (UTC).

A table of contents, a list of abbreviations used in the reportand a list of appendices will enhance the readability of thereport.

1. FACTUAL INFORMATION

This part of the Final Report is descriptive in character andshould be a comprehensive record of the facts andcircumstances established in the investigation. When theinvestigation was conducted by groups, the report shouldcomprise a consolidation of the relevant information fromthe group reports. Supporting documents, such asphotographs, diagrams, relevant parts of flight recorderreadouts and technical reports, should be included orappended to the report. However, only those documents, orportions thereof, which are required to support the facts,analysis and conclusions should be appended to the FinalReport.

The collection of Human Factors information is an integralpart of the investigation. Thus, the Human Factors infor-mation should be integrated into the appropriate areas ofthe factual part of the report, rather than being placed undera separate heading. Human Factors information should bepresented in a language that is consistent with thepresentation of the other factual information.

The factual information part of the Final Report shouldcontain a description of all the events and circumstancesdirectly related to the occurrence. The sequence shouldbegin as far back in time as is necessary to include thesignificant events which preceded the accident. This partalso contains all factual information, i.e. informationresulting from direct verification, which is essential for thedevelopment of the analysis, conclusions and safetyrecommendations. The significance of the facts should not


be explained in the factual information part. Suchdiscussions should be presented in the analysis part.

1.1 History of the flight

1.1.1 The history of the flight describes the significantevents which preceded the accident, in chronological orderwhen this is practicable. The information is usuallyobtained from sources such as flight records, flight datarecorders, cockpit voice recorders, air traffic servicesrecords and recordings, and witness accounts. Theinformation should be correlated to local time, or UTC ifthe flight involved more than one time zone. Theinformation presented in this section of the report should bebased on established facts. Usually the flight number, thetype of operator and operation, the crew briefing and flightplanning, the departure point and time of departure, and thepoint of intended landing will be given, followed by adescription of the events leading to the accident, includingnavigational details and relevant radio communications. Itis important to give a description of the flight and thepertinent events as they occurred, including areconstruction of the significant portion of the flight path,if appropriate. Evidence which facilitated the reconstructionof the sequence of events, such as witness accounts, cockpitvoice recorder and air traffic services transcripts, should bementioned.

1.1.2 In the history of the flight section, the objectiveis to enable the reader to understand how the accidenthappened but to avoid any analysis of why the accidentoccurred.

1.1.3 With regard to the location of the occurrence,include:

— the latitude and longitude, as well as a geographicalreference to a well-known location (such as 75 kmsouth of XYZ);

— the elevation of the accident site;

— time of the occurrence in local time (and UTC if theflight crossed time zones); and

— whether it was day, dawn, dusk or night.

1.2 Injuries to persons

1.2.1 Table 1-1 should be completed in numbers.

1.2.2 Fatal injuries include all deaths determined to bea direct result of injuries sustained in the accident. Seriousinjury is defined in Chapter 1 of Annex 13. For statisticalpurposes, ICAO classifies a fatal injury as an injury whichresults in death within thirty days of the accident. Theheading “Others” in the table refers to persons outside theaircraft who were injured in the accident. When theaccident involves a collision between two aircraft, aseparate table should be used for each aircraft.

1.2.3 Also, the nationalities of the passengers and thecrew should be listed by stating the number of fatalities andserious injuries for each nationality.

1.3 Damage to aircraft

1.3.1 This section should contain a brief statement ofthe damage sustained by the aircraft in the accident

Table 1-1. Injuries to persons

Injuries Crew Passengers Total in the aircraft Others

Fatal

Serious

Minor Not applicable

None Not applicable

TOTAL


(destroyed, substantially damaged, slightly damaged, or nodamage). A detailed description of damage to relevantaircraft components and systems should be included inSection 1.12 — Wreckage and impact information.

1.4 Other damage

1.4.1 Make a brief statement of damage sustained byobjects other than the aircraft, such as buildings, vehicles,navigation facilities, aerodrome structures and installations,and any significant damage to the environment.

1.5 Personnel information

1.5.1 Provide a brief description of the qualifications,experience and history for each flight crew member (pilot,co-pilot and flight engineer) including age, gender, type andvalidity of licences and ratings; flying experience (totalhours), types flown and hours on the type; hours flown inthe last 24 hours, 7 days and 90 days prior to the accident;results of recent training and mandatory and periodicchecks; experience on route and aerodrome involved in theaccident; relevant information on duty time and rest periodsin the 48 hours prior to the accident; significant medicalhistory and medical checks. Also, state the positionoccupied by each flight crew member and identify who wasflying the aircraft.

1.5.2 When relevant to the accident, give a briefstatement of the duties and responsibilities of the cabincrew, as well as their qualifications, experience andtraining. For example, these details would be relevant if theaccident involved an evacuation of the aircraft.

1.5.3 When relevant to the accident, include a briefstatement of the validity of licences and ratings, thequalifications and experience of air traffic servicespersonnel, including age, gender, position manned, totalexperience (in years), and details of experience specific tothe position manned. Details of training and pertinentchecks should be included, as well as duty times and restperiods in the 48 hours prior to the occurrence.

1.5.4 When relevant to the accident, information onmaintenance personnel and other personnel involved shouldinclude qualifications, experience, time on duty, shift workrosters, workload and the time of the day.

1.5.5 Use sub-headings, as appropriate, to organizethe information in this section.

1.6 Aircraft information

1.6.1 When relevant to the accident, provide a briefstatement of the airworthiness and maintenance of theaircraft including the following information:

— General information: Aircraft manufacturer andmodel, serial number and year of manufacture;nationality and registration marks, validity of theCertificate of Registration; name of the owner andthe operator; and validity of the Certificate ofAirworthiness;

— Aircraft history: Total flying hours sincemanufacture, since overhaul, and since last periodicinspection. Include relevant information onmaintenance log and maintenance documentation,compliance (or otherwise) with airworthinessdirectives, manufacturer service bulletins andaircraft modification status;

— Helicopters: Main rotor and tail rotor types andserial numbers. When relevant, include total time,time since overhaul, time since inspection, andcertificated time and cycle limits for relevantcomponents;

— Engines and propellers: Engine manufacturer andmodel, position on the aircraft and engine or enginemodule serial numbers; engine overhaul period ifan engine failure occurred; and total hours, hourssince overhaul and hours since last inspection, foreach engine. If relevant, provide the sameinformation for the propellers;

— Fuel: Type of fuel used and type of fuel authorized.Also, state the amount of fuel on board and how itwas determined, its specific gravity and itsdistribution in the fuel tanks;

— Accessories: In respect of any component whichfailed, give details of the manufacturer, type,model, part and serial number, certificated time andcycle limits, and operating time since manufactureand since overhaul;

— Defects: List any technical defects in the aircraft,engine or accessories which were discovered duringthe investigation or recorded in the appropriate logand not cleared. Indicate whether the defects wererecurring and whether the flight was permissibleunder the aircraft master minimum equipment list.If there were no defects, make a statement to thateffect; and


— Aircraft load: The maximum certificated take-offmass and landing mass, actual take-off mass, andmass at the time of the occurrence should be given.Also, state the certificated limits for the centre ofgravity of the aircraft, and the centre of gravity attake-off and at the time of the occurrence. Includea description of the operator’s loading controlsystem, the load distribution and its security, andhow the details of the aircraft mass and centre ofgravity were established.

1.6.2 Describe any aircraft part or system which hada bearing on the accident. Similarly, describe operationalprocedures, performance limitations and other aircraftrelated circumstances which played a role in the accident.The objective is to enable the reader to fully understandhow the accident happened.

1.6.3 The availability, serviceability and use oftransponder, airborne collision avoidance system (ACAS)and traffic alert and collision avoidance system (TCAS),ground proximity warning system (GPWS) and terrainawareness warning system (TAWS), should be stated. Therelevant systems should be discussed in detail for near-collisions, mid-air collisions, approach and landingaccidents and controlled flight into terrain accidents.

1.7 Meteorological information

1.7.1 Provide a brief statement on the relevantmeteorological conditions, including the forecast and actualweather, together with an appreciation of the weather inretrospect. When relevant to the occurrence, the followinginformation should be included:

— Describe when, where and how the pilot obtainedweather information;

— Weather forecast: Route and aerodrome forecastsavailable to the pilot, and details of any weatherbriefing obtained by the pilot prior to departure orreceived en route;

— Weather observations at the time and place of theoccurrence including precipitation, ceiling,visibility, runway visual range, wind speed anddirection, temperature and dewpoint;

— Actual weather on the route of the flight, includingweather observations, SIGMETs, pilot reports andwitness accounts;

— A general view of the weather situation (synopticweather);

— Weather radar recordings, satellite photos, low-levelwind shear alert system (LLWSAS) data, and otherrecorded meteorological information; and

— Natural light conditions at the time of the accident,such as day (sunlight or overcast), twilight (dawn ordusk; when relevant, the time of sunrise or sunset atthe applicable altitude should be included), night(dark or moonlight) and when relevant, the positionof the sun relative to the direction of the flight.

1.7.2 The amount of meteorological information to beincluded in this section depends on the significance of themeteorological factors in the occurrence. A detaileddescription of the forecast and weather observations isappropriate for a weather-related occurrence whereas abrief summary of the weather is appropriate when theweather was not a factor.

1.8 Aids to navigation

1.8.1 Include relevant information on navigation andlanding aids available, such as global navigation satellitesystem (GNSS), non-directional radio beacon (NDB), veryhigh frequency omnidirectional radio range (VOR),distance measuring equipment (DME), instrument landingsystem (ILS), and visual ground aids, as well as theirserviceability at the time of the accident.

1.8.2 When relevant, include pertinent information onequipment on board the aircraft, such as autoflight system,flight management system (FMS), global positioningsystem (GPS), and inertial navigation system (INS),including their serviceability. Relevant maps, charts,approach plates and radar recordings should also bediscussed and included in, or attached to, the report.

1.9 Communications

1.9.1 Describe the communication facilities availableto the flight crew and their effectiveness. Describe thecommunications with the air traffic services and othercommunications relevant to the flight, including referenceto communication logs and transcripts of recordings. Whenessential to the analysis and understanding of theoccurrence, pertinent extracts from the transcripts of airtraffic services communications recordings should beincluded in this section or attached to the report.


1.10 Aerodrome information

1.10.1 When the occurrence took place during take-off or landing, include information concerning theaerodrome and its facilities. When relevant, include thefollowing information:

— Name of aerodrome, location indicator, referencepoint (latitude/longitude) and elevation;

— Runway identification, runway markings, runwaylength and slope, length of overrun, andobstructions;

— Runway conditions, such as pavement texture andgrooving, rubber deposits, presence of water, slush,snow, ice, friction coefficient and braking action;

— Lighting, such as runway, taxiway and stopwaylighting; and visual aids, such as visual approachslope indicator system (VASIS) and precisionapproach path indicator (PAPI);

— Runway inspection programmes and inspectionscarried out; and

— Bird and wildlife programmes.

1.10.2 If the aircraft was taking off from, or landingon, an area other than an aerodrome, relevant informationon the take-off or landing area should be given.

1.10.3 This section should be divided into departureaerodrome information and destination aerodromeinformation, if both aerodromes were pertinent to theoccurrence.

1.11 Flight recorders

1.11.1 Provide the particulars for each flight recorder,such as manufacturer, model, number of parametersrecorded, recording medium and duration of the recording.The recorders would include flight data recorders (FDR),cockpit voice recorders (CVR), quick access recorders,engine parameter recorders, video recorders, non-volatilememory chips in aircraft systems, and other on-board orground-based recorders.

1.11.2 Describe the condition of the recorders onrecovery, in particular their exposure to fire and impactforces. If the flight recorder(s) could not be recovered, thereasons should be explained. If data was not recorded or

could not be extracted, describe the reasons for themalfunction or loss of data. Include techniques used toextract data and any problems encountered. If the recordersoperated properly, a short statement to this effect should bemade and the pertinent data presented.

1.11.3 In this section, provide information recordedby the flight recorders. Because of the length of a flightdata recording read-out report, include here or in anappendix to the Final Report only those parts of the read-out reports which are pertinent to the analysis and findings.

1.11.4 Transcripts from the cockpit voice recordingsshould be included in the Final Report or its appendicesonly when essential to the analysis and understanding ofthe occurrence. Parts of the recordings not essential to theanalysis shall not be disclosed. Chapter 5 of Annex 13contains provisions pertinent to transcribed voicerecordings and should be taken into account when it isconsidered necessary to include such transcripts in the FinalReport or its appendices.

1.11.5 If the aircraft was not required to be equippedwith flight recorders, a statement along the following linesmay be used: “The aircraft was not equipped with a flightdata recorder or a cockpit voice recorder. Neither recorderwas required by the relevant aviation regulations.”

1.12 Wreckage and impact information

1.12.1 Provide a general description of the site of theaccident and the distribution pattern of the wreckage,including the final portion of the flight path, the impactpath, the impact sequence and the location of impactimpressions on the ground, trees, buildings and otherobjects. The impact heading, aircraft attitude (pitch, rolland yaw) and aircraft configuration at impact should begiven. When relevant, the terrain surrounding the site of theaccident should be described. Relevant wreckage dis-tribution diagrams, charts and photographs should beincluded in this section or appended to the report. Thelocation and the state of the major parts of the wreckageshould be presented. In case of an in-flight break up of theaircraft, a detailed description of the wreckage distributionshould be provided.

1.12.2 In major accident investigations, it might benecessary to present the examination of the wreckage andthe technical investigations under appropriate sub-headingsin this section, such as structures, power plants,instruments, flight controls and systems. The descriptionsunder each sub-heading should embrace the significant


facts determined by the group which was responsible forthe detailed investigation. Under appropriate sub-headingsalso include the relevant results of special technicalinvestigations, examinations and laboratory tests, and thesignificance of the results obtained (see also Section 1.16— Tests and research). When relevant, the technicallaboratory and test reports should be appended to the FinalReport.

1.12.3 It is important to include all pertinent materialfailures and component malfunctions, and to indicatewhether they occurred prior to or at impact. It is essentialthat failed or malfunctioning components which aredeemed to be significant to the accident be described. Adetailed description of all wreckage components is notnecessary; describe only components considered to berelevant or which required examination and analysis. Theinclusion of drawings of components and photographs ofspecific failures will enhance the Final Report. Suchdrawings and photographs could be presented together withthe appropriate text or as an appendix.

1.13 Medical and pathological information

1.13.1 Describe the results of the medical andpathological investigations of the flight crew. Medicalinformation related to flight crew licences should beincluded under Section 1.5 — Personnel information.When relevant to the accident, the medical investigationmay also concern the cabin crew members, passengers andground personnel.

1.13.2 The results of the pathological andtoxicological examinations concerning injuries, detection ofdisease and factors which impaired human performance,such as carbon monoxide, oxygen deficiency, alcohol andother drugs, should be stated. If alcohol and drugs aredetected, their effects on human performance as determinedby medical experts should be presented in this section.

1.13.3 Describe the pathological evidence ofsignificance to the survival investigation such as therelationship of injuries and pathological evidence to thedeceleration forces, aircraft attitude at impact, seat designand attachments, seat belts (see also Section 1.15 —Survival aspects), break-up of the aircraft structure, smokeinhalation, decompression and any evidence of preparationfor an emergency situation, such as forced landing, ditchingand unlawful interference.

1.13.4 Given the provisions of Annex 13, Chapter 5with regard to medical and private records, particular care

should be taken that such information is disclosed in theFinal Report only when pertinent to the analysis andconclusions of the accident.

1.13.5 If the medical examinations indicate that theperformance of flight crew members was not degraded, asentence along the following lines may be used: “Therewas no evidence that physiological factors or incapacitationaffected the performance of flight crew members.”

1.14 Fire

1.14.1 If a fire or an explosion occurred, give a briefdescription of whether the fire started in flight or afterground impact. For in-flight fires, describe the effectivenessof the aircraft fire warning systems and the aircraft fireextinguishing systems. The determination of the origin of afire, source of ignition, fuel source, duration, severity andeffects on the aircraft structure and the occupants usuallyrequires an analysis of the facts and indications, and shouldtherefore be dealt with in the analysis part of the FinalReport. This section should describe the factual informationwhich was established in the investigation related to the fireand which should then be discussed and analysed in theanalysis part.

1.14.2 For fires on the ground, describe thepropagation and the extent of the fire damage. The responsetime of the rescue fire service, access to the accident site bythe rescue fire service vehicles, the type of fire fightingequipment used, the type of extinguishing agent and theamount that was used and its effectiveness should also bedescribed.

1.14.3 The effect of the fire on the evacuation andsurvivability of the occupants should be described inSection 1.15 — Survival aspects.

1.14.4 If there was no fire, a sentence along thefollowing lines may be used: “There was no evidence offire in flight or after the impact.”

1.15 Survival aspects

1.15.1 Give a brief description of the search andrescue activities. When applicable, include informationregarding the serviceability and effectiveness of theemergency locator transmitters.

1.15.2 The location of crew members and passengersin relation to injuries sustained should be stated. The failure


of structures, such as seats, seat belts and overhead binsshould be described. Also, the use and effectiveness ofsafety equipment should be reported. Aspects pertinent tothe crashworthiness of the aircraft should be addressed, aswell as occupant survivability in relation to impact forcesand fire.

1.15.3 If an evacuation was conducted, a descriptionof the following information is usually included:

— first notification of an accident to the emergencyservices and the response time;

— emergency lighting in the aircraft (installation,activation, functioning and failures);

— communications;

— passenger behaviour and carry-on baggage;

— emergency exits (types of exits and their use);

— evacuation slides (types of slides, activation andtheir use);

— injuries sustained in the evacuation; and

— post-evacuation events.

1.16 Tests and research

1.16.1 Describe the results of any tests and researchundertaken in connection with the investigation. Flighttests, simulator tests and computer modelling of aircraftperformance are examples of the type of information thatshould be included in this section. Relevant details ofresearch that is used to support the analysis should also beincluded.

1.16.2 The results of examinations of aircraft andengine parts may alternatively be included in Sections 1.6— Aircraft information, 1.12 — Wreckage and impactinformation or 1.16.

1.17 Organizational and management information

1.17.1 When relevant to the accident, providepertinent information on any organization and its manage-ment whose activities may have directly or indirectlyinfluenced the operation of the aircraft. The organizationsto be addressed in this section could include:

— operator;

— maintenance organizations;

— air traffic services;

— aerodrome administration;

— meteorological services;

— aircraft manufacturer;

— certification and licensing authority; and

— regulatory authority.

1.17.2 When deficiencies in the organizationalstructure and functions had a bearing on the accident, theinformation could include, but need not be limited to, thefollowing factors:

— safety culture;

— resources and financial viability;

— management policies and practices;

— internal and external communications; and

— certification, safety oversight and regulatoryframework.

1.17.3 When relevant, provide pertinent informationconcerning the operator, such as type and date of issuanceof the air operator certificate, types of operationsauthorized, types and number of aircraft authorized for use,and authorized areas of operation and routes. Also, includeinformation concerning any deficiencies found in theoperator’s company operations manual and other operatordocumentation, when the deficiencies had a bearing on theaccident.

1.18 Additional information

1.18.1 Give relevant information and facts, notalready included in Sections 1.1 to 1.17, which are essentialto the development of the analysis and conclusions parts ofthe Final Report.

Note.— Ensure that the factual information part of theFinal Report contains all the technical data which isessential to the analysis and conclusions parts of the report.


1.19 Useful or effective investigation techniques

1.19.1 When useful or effective investigationtechniques have been used during the investigation, brieflydescribe the main features of these techniques and theirpertinence to future investigations. However, the data andthe results obtained as they relate to the accident, should beincluded under the appropriate Sections 1.1 to 1.18. Thefull report on the use of these techniques may be includedas an appendix to the Final Report.

2. ANALYSIS

2.1 In the analysis part of the Final Report, thesignificance of the relevant facts and circumstances whichwere presented in the factual information part should bediscussed and analysed in order to determine which eventscontributed to the accident. There might be a necessity torepeat the description of some of the evidence alreadypresented in the factual information part, however, theanalysis should not be a restatement of the facts. Also, nonew facts should be introduced in the analysis part. Thepurpose of the analysis is to provide a logical link betweenthe factual information and the conclusions that provide theanswer to why the accident occurred.

2.2 The analysis part should contain an evaluation ofthe evidence presented in the factual information part andshould discuss the circumstances and events that existed ormay have existed. The reasoning must be logical and maylead to the formulation of hypotheses which are thendiscussed and tested against the evidence. Any hypothesiswhich is not supported by the evidence should beeliminated; it is then important to clearly state the reasonswhy a particular hypothesis was rejected. When ahypothesis is not based on fact but is an expression ofopinion, this should be clearly indicated. As well, thejustification for sustaining the validity of a hypothesisshould be stated and reference should be made to thesupporting evidence. Contradictory evidence must be dealtwith openly and effectively. Cause-related conditions andevents should be identified and discussed. The discussionin the analysis should support the findings and theimmediate and systemic causes of the accident.

2.3 Also, discuss and analyse any issue that came tolight during the investigation which was identified as asafety deficiency, although such issue may not havecontributed to the accident.

2.4 Because the Final Report is often drafted as theinvestigation progresses and several investigators (all the

groups in a major investigation) will contribute to theanalysis part of the report, the development of an outlineand sub-headings for the analysis part will ensure that theinvestigators know their drafting assignments. Such anoutline will also indicate to the investigators how the sub-headings will come together in forming the analysis part ofthe Final Report. An example of such an outline is providedin Table 1-2.

3. CONCLUSIONS

This part should list the findings and the causes establishedin the investigation. The conclusions are drawn from theanalysis. However, it is essential to maintain the samedegree of certainty in a conclusion as was established in theanalysis. For example, if the discussion in the analysisindicates that an event or circumstance was likely, then thefinding should contain the same qualifier (likely).

3.1 Findings

3.1.1 The findings are statements of all significantconditions, events or circumstances in the accidentsequence. The findings are significant steps in the accidentsequence, but they are not always causal or indicatedeficiencies. Some findings point out the conditions thatpre-existed the accident sequence, but they are usuallyessential to the understanding of the occurrence. Thefindings should be listed in a logical sequence, usually in achronological order.

3.1.2 All findings must be supported by and directlyrelated to the factual information and the analysis. No newfactual information should be introduced in the findings.

3.1.3 It is customary to report on certain conditions inevery investigation, such as the validity of licences, thetraining and experience of the flight crew members, theairworthiness and maintenance of the aircraft, the loadingof the aircraft, and whether there was a pre-impact failure.The following findings are typical of what is usuallyincluded:

— The flight crew members were licensed andqualified for the flight in accordance with existingregulations;

— The maintenance records indicated that the aircraftwas equipped and maintained in accordance withexisting regulations and approved procedures;


Table 1-2. Example outline for the analysis part

EXAMPLE OF SUB-HEADINGS IN THE ANALYSIS PART

An aircraft impacts the ground short of the runway during an instrument approach in marginal weather. Some of theoccupants are killed or injured. Based on these few facts, the investigator-in-charge can identify many of the areas tobe investigated and analysed. At an early stage of the investigation, the investigator-in-charge is able to allocatedrafting assignments to the investigators for tentative sub-headings in the analysis part, as follows:

2.1 General

2.2 Flight operations

2.2.1 Crew qualifications2.2.2 Operational procedures2.2.3 Weather2.2.4 Air traffic control2.2.5 Communications2.2.6 Aids to navigation2.2.7 Aerodrome

2.3 Aircraft

2.3.1 Aircraft maintenance2.3.2 Aircraft performance2.3.3 Mass and balance2.3.4 Aircraft instrumentation2.3.5 Aircraft systems

2.4 Human Factors

2.4.1 Psychological and physiological factors affecting the personnel involved

2.5 Survivability

2.5.1 Rescue fire service response2.5.2 Analysis of injuries and fatalities2.5.3 Survival aspects

The tentative sub-headings in the analysis part may require adjustments as the investigation progresses, but the listidentifies the major areas that should be covered in the analysis. The list is a good starting point as it indicates to theinvestigators where each drafting assignment for the sub-headings will fit into the analysis part as a whole.


— The mass and centre of gravity of the aircraft werewithin the prescribed limits; and

— There was no evidence of airframe failure or systemmalfunction prior to the accident.

3.1.4 Significant events and factors that wereinvestigated in detail, but eliminated in the analysis, shouldalso be stated in the findings. For example, findings such as“flight crew fatigue was not a factor in the accident” and“there was no malfunction of the elevator control system”should be considered when a comprehensive investigationwas made into these aspects. Areas of ambiguity should beidentified and stated, for example, “the investigation wasunable to establish whether the pilot-in-command or the co-pilot was the pilot flying the aircraft at the time of theaccident”.

3.1.5 Some States present the causes of the accidentseparately from the findings under their own heading.Other States indicate in the list of findings which of thefindings were causes of the accident, for example by addingafter such a finding “(causal factor)” or “(contributoryfactor)”.

3.1.6 Examples of frequently used findings inaccident reports are listed in Appendix 5 to Chapter 1.

3.2 Causes

3.2.1 Causes are those events which alone, or incombination with others, resulted in injuries or damage. Acause is an act, omission, condition or circumstance whichif eliminated or avoided would have prevented theoccurrence or would have mitigated the resulting injuries ordamage.

3.2.2 The determination of causes should be based ona thorough, impartial and objective analysis of all theavailable evidence. Any condition, act or circumstance thatwas a causal factor in the accident should be clearlyidentified. Seen together, the causes should present apicture of all the reasons why the accident occurred. The listof causes should include both the immediate causes and thedeeper or systemic causes. No new information should beintroduced in the causes. The causes should be presented ina logical order, usually chronological order, bearing inmind that it is essential that all the causes be presented. Thecauses should be formulated with preventive action in mindand linked to appropriate safety recommendations.

3.2.3 Some States list the causes, usually sequentiallyas they occurred, without attempting to prioritize thecauses. Other States would prioritize the causes by usingterms such as primary causes and contributing causes.

3.2.4 When certain of a cause, a definite statementshould be used; if reasonably sure of a cause, a qualifyingword such as “probable” or “likely” should be used. Thecauses statement is usually a reiteration of statements madeat or near the end of the analysis and in the findings. Forexample, if the analysis and the findings state that a cause-related event or circumstance was “probable”, then thecauses statement should contain the same qualifier(probable).

3.2.5 When there is insufficient evidence to establishwhy an accident occurred, there should be no hesitation instating that the causes remain undetermined. In manyinstances, the most likely scenario could be stated providedthat a qualifier, such as “likely” or “probable” is included.However, a list of possible causes should not be given.

3.2.6 The causes should be formulated in a waywhich, as much as practicable, minimizes the implication ofblame or liability. Nevertheless, the accident investigationauthority should not refrain from reporting a cause merelybecause blame or liability might be inferred from thestatement of that cause. An example of a formulation of thecauses is given in Table 1-3.

4. SAFETY RECOMMENDATIONS

4.1 In accordance with Annex 13, the sole objectiveof the investigation of an accident shall be the preventionof accidents and incidents. Therefore, the determination ofappropriate safety recommendations is of utmostimportance. The safety recommendations are actions whichshould prevent other accidents from similar causes orreduce the consequences of such accidents. In order toensure that appropriate action is taken, each safetyrecommendation should include a specific addressee. Thisis usually the appropriate authority of the State which hasresponsibility for the matters with which the safetyrecommendation is concerned.

4.2 Annex 13 requires that at any stage of theinvestigation of an accident, the accident investigationauthority of the State conducting the investigation shallrecommend to the appropriate authorities, including thosein other States, any preventive action that is considerednecessary to be taken promptly to enhance aviation safety.The interim safety recommendations made during the


Table 1-3. Example of causal statements

EXAMPLE OF FORMULATION OF CAUSES

One accident — same causes

The causes of this accident were: The causes of this accident were:

• the failure of airport management to identify andcorrect poor runway drainage;

• the known and uncorrected lack of runway drainage;

• the failure of the air traffic controllers to informthe flight crew that there was standing water on therunway;

• lack of communication between the ATC and theflight crew regarding the degenerated runwaycondition;

• the flight crew’s mismanagement of the aircraft’sairspeed; and

• the aircraft crossing the threshold 16 knots aboveVref; and

• the flight crew’s mismanagement of thrustreversers.

• the late application of reverse thrust.

Note. — The causal statement to the left implicates three groups of persons -— the flight crew, the airportmanagement and the air traffic controllers. Since the formulation of causes should not be blame-setting in nature,the statement on causation should focus on functions that in the example case were not performed at the level requiredfor safe operation. Such a functional statement logically leads to corrective or preventive measures that should berecommended to prevent future accidents.

investigation may be presented in the safetyrecommendations part of the Final Report. Also, thepreventive actions taken in response to the interimrecommendations should be presented, as well as any otherpreventive actions taken by the appropriate authorities andthe industry, such as changed operating procedures by theaircraft operator and the issuance of service bulletins by themanufacturer. Some States present the interim safetyrecommendations and describe the preventive actions takenin the factual information part, Section 1.18, in lieu ofincluding this information in the safety recommendationspart. Publishing the preventive actions taken in the FinalReport has significant accident prevention value for thoseinvolved in similar operations.

4.3 A safety recommendation should describe thesafety problem and provide justification for safety actions.An example of a recommendation is given in Table 1-4.Attention should be focussed on the problem rather than thesuggested solution. Consideration should be given towhether a safety recommendation should prescribe aspecific solution to a problem or whether therecommendation should be flexible enough to allow theaddressee latitude in determining how the objective of therecommendation can be achieved. A safety recommen-dation should identify what actions to take, but leave scope

for the authorities responsible for the matters in question todetermine how to accomplish the objective of therecommendation. This is particularly important if all thesalient facts are not available and additional examination,research and testing appears necessary. In addition, theaccident investigation authority may lack the detailedinformation and experience required to evaluate thefinancial, operational and policy impacts on the addresseeof specific and detailed recommendations.

4.4 During aircraft accident investigations, safetyissues are often identified which did not contribute to theaccident but which, nevertheless, are safety deficiencies.These safety deficiencies should be addressed in the FinalReport. Some States include safety recommendations notrelated to the causes of the accident in the safetyrecommendations part of the Final Report. Other Stateshave adopted means other than the Final Report to notifythe appropriate authorities of safety deficiencies that are notrelated to the accident, although the actions taken areusually described in the Final Report.

4.5 In summary, the safety recommendations shouldinclude a convincing presentation of the safety problem withthe attendant safety risks deriving from it, as well as arecommended course of action for the responsible authority


to take in order to eliminate the unsafe condition. The safetyrecommendations should identify what action is required, butshould leave considerable scope for the implementingauthority to determine how the problem will be resolved.

APPENDICES

The appendices should include, as appropriate, anypertinent information considered necessary to understandthe report, such as a glossary, supporting technical reports,accident site diagrams, photographs and flight recorderdata. Graphics and diagrams should have a professional

appearance and should show only the information requiredfor understanding the report. The appendices should benumbered and listed in the table of contents. The followingis a list of appendices commonly found in a Final Report:

— communications transcripts;— flight data recorder readouts;— flight plan and loadsheet;— technical investigation reports;— pertinent pages from manuals and handbooks;— pertinent maintenance records;— maps and diagrams; and— photographs.

Table 1-4. Example of a safety recommendation

EXAMPLE OF THE WORDING OF A SAFETY RECOMMENDATION

Consider the following safety recommendation:

“ICAO should establish a working group to clarify the international Standards and Recommended Practices inAnnex 14 regarding the marking of runway centrelines in relation to co-located threshold markings and turn-around areas.”

In accordance with the guidance above, the addressee (in this example ICAO) should be given sufficient latitudein determining how to achieve the objective of the recommendation. It should be left to ICAO to determine howthe work is to be undertaken, e.g. working group, consultant or panel. A general statement, such as “internationalrequirements” could also be used, thus leaving it to ICAO to determine whether Standards, RecommendedPractices and/or guidance material would be appropriate to meet the objective of the recommendation. Based onthe foregoing reasoning, the following formulation of the safety recommendation would be preferable:

“The (accident investigation authority) recommends that ICAO re-examine the international requirements inAnnex 14 regarding the marking of runway centrelines in relation to co-located threshold markings and turn-around areas.”


Appendix 2 to Chapter 1REPORT WRITING CONVENTIONS

1. GENERAL GUIDELINES

The purpose of writing any report is to convey the facts ofthe subject of the report to its readers in a succinct, clear,unambiguous and well organized manner. When draftingthe Final Report, the writer should not assume thateveryone who reads the report is familiar with the technicaldetails. Therefore, information should not be omittedbecause it is obvious to the writer. The writer shouldremember that the readers will not have visited the accidentsite, nor did they participate in the investigation. Thewriter’s responsibility is to present the reader with a wordpicture of the accident and the investigation. The writershould assume that the reader is intelligent but uninformedand will analyse the facts presented in order to test theconclusions of the Final Report. For example, if it isobvious to the writer that the weather was not a factor inthe accident, this should be clearly stated, but neverthelessthe reader should be provided with enough weatherinformation to substantiate the conclusion.

2. EDITORIAL STANDARDS

2.1 Convey an attitude of impartialityand write objectively

2.1.1 The report should not favour any party involvedwith the accident, e.g. the pilot, the operator, the aircraftmanufacturer or special interest groups, such as advocatesfor noise abatement, nor should it reflect prejudice againstany party.

2.1.2 The straightforward descriptive narrative whichavoids flowery descriptions and human interest itemsshould be used. Clues to the investigator’s personality orprejudices should not be apparent to the reader. Theindiscriminate use of adjectives and adverbs is usually notacceptable in accident report writing.

2.1.3 The writer should write to express the facts, notto impress the reader. If the Final Report must delve intocomplicated areas such as aerodynamics, metallurgy, andthe operation of aircraft systems, the subject should beexplained in a way that it is easy to understand. To maintain

the readability of the body of the Final Report, complexsubjects may be explained in an appendix to the FinalReport.

2.1.4 Subjects of equal importance should be givenequal coverage when describing the facts, conditions andcircumstances.

2.2 Clarity

2.2.1 The use of an outline, such as that provided inthe Appendix to Annex 13, is a commonsense approach tothe task of writing the Final Report.

2.2.2 Clarity in report writing can be enhanced byreporting sequentially. The History of the flight, forexample, should describe the flight in a logical sequencefrom start to finish. Placing events out of sequence tends toconfuse the reader.

2.2.3 Each sentence should be a logical unit. Thewriter should keep the subject of the sentence and its verbclose together. Long asides between the subject and theverb interrupt the flow of the sentence. The informationshould be organized logically within each section andgrouped under an appropriate heading.

2.2.4 The writer should provide the reader with alead-in and context for new information or ideas by firstreferring to any related information already presented.

2.2.5 Pronouns, especially “this”, “that” and “it”should be placed close to their antecedents to ensure clarity.A pronoun should refer to a specific antecedent rather thanan implied antecedent.

2.2.6 Sentences should begin with the real subject ofthe sentence, rather than with subjects such as “It is...” or“There are...”.

2.2.7 The writer should select the words that bestdescribe the situation. Vague terminology should beavoided, for example, “Damage to the aircraft appeared tobe the result of impact loading” and “It was presumed thatthe aircraft started to cartwheel after striking the leftwingtip”. Words such as appeared, seemed and presumed


are not precise enough for the factual part of the report. Theinvestigator must report evidence found and not that whichappeared, seemed, or was presumed to have been.

2.2.8 The findings and statements in the report mustbe unambiguous and subject to only one interpretation.

2.3 Conciseness

2.3.1 Long sentences might make it difficult for thereader to comprehend the point the writer is trying to make.This does not mean that the report should consist entirelyof simple sentences. Long sentences are acceptable ifunderstandable. Any sentence which must be re-read to beunderstood is too long.

2.3.2 The writer should avoid unnecessary repetition,and extraneous and irrelevant data, which might confusethe reader and may cloud the reader’s comprehension of theconclusions.

2.4 Consistency

The writer should verify that the terminology used isconsistent throughout the report. The writer should use thesame terms for the same things, and should spell,hyphenate and abbreviate words consistently. When usingabbreviations, the writer should spell out the words in fullfollowed by the short form in parentheses the first time theyare used. Thereafter, the abbreviations should be used. Allthe abbreviations used should be included in a glossary.

2.5 Gender

Avoid gender stereotyping, such as referring to theinvestigator-in-charge or an engineer by using the pronoun“he”.

3. ACTIVE VS. PASSIVE VOICE

3.1 The choice of voice has a great effect on the forceof the narrative. The active voice is more vigorous and lessambiguous than the passive. Use of the passive voice oftenleads to wordiness, fuzziness and sometimes grammaticalerrors. In most cases, the active voice is preferable. Forexample, “When the pilot detected a fuel leak...” ispreferable to “When a fuel leak was detected by thepilot...”.

3.2 The passive voice is more appropriate in somecases, such as:

— when the agent, or doer of the act, is unknown;— when a reference to the actor is inappropriate; and— when the agent is less important than the action,

e.g. “The two survivors were rescued...”.

3.3 The writer should recognize when each voice isappropriate and not overuse the passive voice.

4. READ AND REVISE

4.1 Revising is a part of writing. Few investigatorscan express clearly on the first attempt what they intend toconvey. One means of improving clarity is through thewrite – read, re-write – re-read process. The writer shouldreview what he/she has written and check if it needs furtherclarification, shortening, rearrangement or other changes.Experienced writers find advantage in setting the reportaside for a day or more before making a critical review toensure that it conveys the intended meaning. Solicitingcomments from other investigators often pinpointsambiguous areas of the report in which the writer shouldmake improvements. Comments from other investigatorsshould be accepted as constructive and not as personalcriticism.

4.2 The writer should edit the report to ensure that itis logical and consistent. Some of the common traps indrafting a report are:

— Hasty generalization: basing a conclusion on toofew instances, e.g. “Three of the ten witnessesagreed that the pilot was flying too low”;

— Using absolute words such as “always” or “never”:such words are seldom appropriate, e.g. “Mid-aircollisions are always the result of pilot inattention”;

— Oversimplification: linking two events as if onecaused the other when the relationship betweenthem is more complex, e.g. “This practice violatedfundamental flying principles”;

— Asserted conclusion: drawing conclusions frominsufficient data, e.g. “Based on wide experience,the experts concluded that landing accidents are theresult of unstable approaches”;


— Post hoc fallacy: assuming that because one eventfollows another, the second event was caused by thefirst, e.g. “Inexperienced pilots are more susceptibleto CFIT accidents”;

— Either/or fallacy: assuming that a complicatedquestion has only two possible answers, e.g. “Thechoice was to fly the mission in accordance withthe company directives or not to fly it at all”;

— Non sequitur: drawing a conclusion that bears nological relation to the facts presented, e.g. “Becauseof his position as Director of Flight Operations, hewas fully qualified to assess the qualifications of hispilots”; and

— False analogy: suggesting that because two thingsor situations share some similarities, they must bealike in other ways, e.g. “Flying an aircraft at nightis no different to flying it during the day in IMC”.

5. TONE OF EXPRESSION

5.1 Blame or liability

5.1.1 Annex 13 states that it is not the purpose of theinvestigation to apportion blame or liability. Nevertheless,blame or liability might sometimes be inferred from thefindings. When such is the case, it is essential that all thecauses established be clearly presented in the report. To dootherwise would jeopardize the objective of the investi-gation which is the prevention of accidents and incidents.

5.1.2 Avoid words or phrases that have connotationsof blame. For instance, use the statement “The operator didnot notify...” rather than “The operator failed to notify...”.An investigator should not write from the perspective of aregulator who is concerned about non-compliance withrules and regulations, nor from the perspective of amanager in a company, where determination of support fordisciplinary or legal action may be an objective.

5.2 Contravention of regulationsand orders

5.2.1 Deviations from the accepted norms ofcompliance with regulations and procedures should beclearly identified when relevant to the accident. The natureof the regulation and the extent of the deviation should bedescribed in sufficient detail in order to explain the safetyimplications of the deviation. The analysis should explainthe reasons why the deviation created a hazard.

5.2.2 For a contravention to be included as a cause, itshould be clear that complying with the regulation orprocedure could have prevented the accident or lessenedthe consequences of the accident.

5.3 Human suffering

The writer must recognize the human suffering that isassociated with an accident by using respectful and discreetlanguage in the report. If sensitive information must bereported because it pertains to the causes or safetydeficiencies, it should be reported with due sensitivity.

6. COMMONLY USED LANGUAGE

Many accident investigation authorities employstandardized phraseology for the details which are recordedin any Final Report on an accident, such as crewqualifications and aircraft serviceability. Refer toAppendix 5 to Chapter 1 — Commonly used findings.

7. GLOSSARY

A glossary should be appended to the Final Report. Onlythe abbreviations used in the report should appear in theglossary.


Appendix 3 to Chapter 1SYMBOLS AND ABBREVIATIONS

1. INTRODUCTION

1.1 This appendix presents a list of symbols andabbreviations which might be used in a Final Report. Notethat symbols which are comprised of letters are presentedamong the abbreviations.

1.2 When compiling a glossary of abbreviations foran accident report, include only those abbreviations used inthe report.

2. SYMBOLS

° Degree (examples °C (temperature) and 1° (angle))% Per cent (example 95% fan speed (N1))' Minute” Second

3. ABBREVIATIONS

A

AC Alternating currentAdvisory circular

ACARS Aircraft communications addressing andreporting system

ACAS Airborne collision avoidance systemACC Area control centreAD Airworthiness DirectiveADF Automatic direction-finderADI Attitude direction indicatorADIZ Air defence identification zoneADS Automatic dependent surveillanceAFCS Automatic flight control systemAFIS Aerodrome flight information serviceAFTN Aeronautical fixed telecommunication

networkAGL Above ground levelAIC Aeronautical information circularAIP Aeronautical Information PublicationAIREP Air-report

AMSL Above mean sea levelANO Air navigation orderAOA Angle of attackAOC Air Operator CertificateAOM Aircraft Operating ManualAPP Approach control office

Approach controlApproach control service

APU Auxiliary power-unitARTCC Air route traffic control centreASI Airspeed indicatorASR Airport surveillance radarATC Air traffic controlATCC Air traffic control centreATFM Air traffic flow management ATIS Automatic terminal information serviceATPL Airline Transport Pilot LicenceATS Air traffic servicesAVASIS Abbreviated visual approach slope

indicator system

B

C

C Degrees Celsius (Centigrade)Centre (runway identification)

CAA Civil aviation authorityCivil aviation administration

CADC Central air data computer CAM Cockpit area microphoneCAS Calibrated airspeedCAT Clear air turbulence

CategoryCAVOK Visibility, cloud and present weather

better than prescribed values andconditions (cloud and visibility OK)

CFIT Controlled flight into terrain CG Centre-of-gravitycm Centimetre(s)C of A Certificate of airworthinessCPL Commercial Pilot LicenceCRM Crew resource managementCRT Cathode-ray tubeCTA Control areaCVR Cockpit voice recorder


D

DA Decision altitudeDA/H Decision altitude/heightDC Direct currentDFDR Digital flight data recorderDH Decision heightDME Distance measuring equipment

E

E EastEastern longitude

EAS Equivalent airspeedECAM Electronic centralized aircraft monitorEICAS Engine indication and crew alerting

systemEFIS Electronic flight instrument systemEGPWS Enhanced ground proximity warning

systemEGT Exhaust gas temperatureELT Emergency locator transmitterEMI Electromagnetic interferenceEPR Engine pressure ratio ETA Estimated time of arrival

Estimating arrivalETD Estimated time of departure

Estimating departure

F

FAF Final approach fixFAP Final approach pointFAR Federal Aviation RegulationsFCOM Flight Crew Operating ManualFD Flight directorFDAU Flight data acquisition unitFDM Flight deck managementFDR Flight data recorderFIR Flight information regionFIS Flight information serviceFL Flight levelFMC Flight management computerFMS Flight management systemFOD Foreign object damage (also the object)FSS Flight service stationft Foot (feet)ft/min Feet per minute

G

g Normal accelerationGNSS Global navigation satellite system

GPS Global positioning systemGPWS Ground proximity warning system

H

h Hour(s)HF High frequency (3 000 to 30 000 kHz)Hg MercuryhPa HectopascalHSI Horizontal situation indicatorHUD Head-up displayHz Hertz (cycle per second)

I

IAF Initial approach fixIAS Indicated airspeedIFR Instrument flight rules IIC Investigator-in-chargeILS Instrument landing systemIMC Instrument meteorological conditionsINS Inertial navigation systemIRS Inertial reference systemISA International standard atmosphere

J

JAR Joint Aviation Requirements

K

kg Kilogram(s)kHz Kilohertzkm Kilometre(s)km/h Kilometres per hourkN Kilonewtonkt Knot(s)

L

L Litre(s)Left (runway identification)

LDA Landing distance availableLED Light emitting diodeLF Low frequency (30 to 300 kHz)LLWS Low-level wind shearLOFT Line-oriented flight trainingLORAN Long range air navigation system

M

m Metre(s)M Mach number


MAC Mean aerodynamic cordMDA Minimum descent altitudeMDA/H Minimum descent altitude/heightMDH Minimum descent heightMEL Minimum equipment listMET Meteorological

MeteorologyMeteorological services

MHz Megahertzmin Minute(s)MLS Microwave landing systemmm Millimetre(s)MMEL Master minimum equipment listMOC Minimum obstacle clearance (required)MOPS Minimum operational performance

standardsMSA Minimum sector altitudeMSL Mean sea levelmu Coefficient of sliding friction

N

N NorthNorthern latitudeNewton

N1 Engine fan speed (high pressure turbinespeed)

N2 Engine compressor speedNDB Non-directional radio beaconNDT Non-destructive testingNOTAM Notice to airmen (a notice distributed by

means of telecommunication containinginformation concerning the establish-ment, condition or change in anyaeronautical facility, service, procedure orhazard, the timely knowledge of which isessential to personnel concerned withflight operations)

NM Nautical mile(s)

O

OAT Outside air temperatureOCA Obstacle clearance altitudeOCH Obstacle clearance heightOCL Obstacle clearance limitOCS Obstacle clearance surfaceOPS Operations

P

PA Public address systemPANS Procedures for Air Navigation Services

PAPI Precision approach path indicatorPAR Precision approach radarPCU Power control unit PIC Pilot-in-commandPIREP Pilot reportP/N Part number

Q

QA Quality assuranceQAR Quick access recorderQFE Atmospheric pressure at aerodrome

elevation (or at runway threshold)(pressure setting to indicate height aboveaerodrome)

QNH Altimeter sub-scale setting to obtainelevation when on the ground (pressuresetting to indicate elevation above meansea level)

R

RA Radio altimeterResolution advisory

RCC Rescue coordination centreRESA Runway end safety areaRF Radio frequencyRFFS Rescue and fire fighting serviceRMI Radiomagnetic indicatorRNAV Area navigationRPM Revolutions per minuteRTF RadiotelephonyRVR Runway visual range

S

s Second(s)S South

Southern latitudeSAR Search and rescueSAS Stability augmentation systemSB Service BulletinSCAS Stability and control augmentation

systemSDR Service difficulty reportSEM Scanning electron microscopeSI International system of unitsSID Standard instrument departureSIGMET Significant meteorological information

(information concerning specified en-route weather phenomena which mayaffect the safety of aircraft operations)

SL Service Letter


SMC Surface movement controlSMR Surface movement radarS/N Serial numberSPECI Aviation selected special weather reportSRA Surveillance radar approachSSR Secondary surveillance radarSTAR Standard instrument arrivalSTOL Short take-off and landingSVR Slant visual range

T

t TonneTAF Terminal aerodrome forecastTAR Terminal area surveillance radarTAS True airspeedTAWS Terrain awareness and warning systemTCAS Traffic alert and collision avoidance

systemTCH Threshold crossing heightTDP Take-off decision pointTDZ Touchdown zoneTMA Terminal control areaTODA Take-off distance availableTORA Take-off run availableTRACON Terminal radar approach controlTWR Aerodrome control tower

Aerodrome control

U

UAC Upper area control centreUAR Upper air routeUHF Ultra-high frequency (300 to 3 000

MHz)ULB Underwater locator beaconUTC Coordinated Universal Time

V

VASIS Visual approach slope indicator systemVFR Visual flight rulesVHF Very high frequency (30 to 300 MHz)VMC Visual meteorological conditionsVOR VHF omnidirectional radio rangeVSI Vertical speed indicatorVTOL Vertical take-off and landing

V SPEEDS

V1 Decision speedV2 Take-off safety speedVMCA Minimum control speed in the airVMCL Minimum control speed during landing

approach with all engines operatingVMO/MMO Maximum permissible operating speed

or maximum permissible operatingMach number

VNE Never exceed airspeedVR Rotation speedVREF Reference landing approach speed, all

engines operatingVS Minimum calibrated speed in flight

during normal stall manoeuvreVS1 Stalling speed (“clean” configuration)

W

W WestWestern longitude

X

Y

Z


Appendix 4 to Chapter 1AVIATION TERMINOLOGY

INTRODUCTION

This appendix comprises two sections. The first sectionis titled Descriptive Technical Terms and lists technicalterms which have a specific meaning and an explanatorydefinition. The second section presents some commonlyused Human Factors Terms.

1. DESCRIPTIVE TECHNICAL TERMS

Arcing. Visible effects (burn spots, fused metal) of anelectrical discharge between two electrical connections.Also: flash over.

Battered. Damaged by repeated blows or impacts.

Bent. Deviated from original line or plane usually causedby lateral force. Also: creased, folded, kinked.

Binding. Restricting movement, such as tightened or stickingcondition, may result from high or low temperature or aforeign object jammed in mechanism. Also: sticking,tight.

Bowed. Curved or gradually deviated from original line orplane often caused by lateral force or heat.

Brinelling. Circular surface indenting of bearing races,usually caused by repeated shock loading of thebearing. False brinelling is wear caused by bearingrollers sliding back and forth across a stationary race,while true brinelling is plastic displacement of material.

Broken. Separated by force into two or more pieces. Also:fractured.

Bulged. Swollen outward locally. Usually caused byexcessive local heating or differential pressure. Also:ballooned, swelling.

Burned. Oxidized destructively. Usually caused by highertemperature than the parent material can withstand.

Burrs. A rough edge or a sharp projection on the edge orsurface of the parent material.

Carboned. Covered by an accumulation of carbon deposits.Also: carbon-covered, carbon-tracked, coked.

Chaffed. Worn by frictional damage. Usually caused bytwo parts rubbing together with limited motion.

Checked. Cracked on the surface. Usually caused by heat.

Chipped. Broken away at the edge, corner or surface of theparent material. Usually caused by heavy impact; notflaking.

Collapsed. Inwardly deformed original contour of a part.Usually due to high pressure differentials.

Corroded. Gradually destroyed by chemical action. Oftenevidenced by oxide build-up on the surface of theparent material. Also: rusted, oxidized.

Crack. Visible partial separation of material.

Crossed. Damaged parent material of parts due to improperassembly (as in the case of crossed threads) or partsrendered inoperative (as in the case of crossed wires).

Curl. A condition where the tip(s) of compressor or turbineblades have been curled over due to rubbing againstengine casings.

Dented. Damage by impact of a foreign object resulting in asurface indentation with rounded bottom. Parent materialis displaced, but seldom separated. Also: peened.

Deposits. A build-up of material on a part either fromforeign material or from another part not in directcontact. Also: metalizing.

Disintegrated. Separated or decomposed into fragments.Excessive degree of fracturing (breaking) as withdisintegrated bearings. Complete loss of original form.Also: shattered.

Distortion. Extensive deformation of the original contourof a part usually due to impact of a foreign object,structural stress, excessive localized heating or anycombination of these. Also: buckled, depressed,twisted, warped.


Eccentricity. Part(s) wherein the intended common centeris displaced. Also: non-concentric.

Electrical circuits — grounded. Circuits in which thecurrent has a path to ground.

Electrical circuits — open. Incomplete electrical circuitdue to separation at or between electrical connections.

Electrical circuits — shorted. Circuits in which the currenthas an undesired path between leads or circuits that arenormally at different electrical potentials.

Eroded. Component from which material has been carriedaway by flow of fluids or gases; may be accelerated byheat or grit.

Fatigue. The progressive failure of a part under repeatedloading.

Flattened out. Permanent loss of curvature beyondtolerance limits. Usually caused by compression.

Frayed. Worn into shreds by rubbing action.

Fretting. Removal of material by rubbing.

Fusing. Joining together of two materials. Usually causedby heat, friction or electrical current flow.

Galling. Chafing or severe fretting caused by relativemovement of two surfaces under high contact pressure.

Glazing. Undesirable development of a hard, glossy surfacedue to rubbing action, heat or varnish.

Gouging. Scooping out of material usually caused by aforeign object. Also: furrowed.

Groove(s). Smooth, rounded furrow or furrows of wear,usually wider than scoring, with rounded corners and asmooth groove bottom.

Hot-spot. Result of subjection to excessive temperatureusually evidenced by change in colour and appearanceof part. Also: heat discoloured, overheated.

Melted. Deformed from the original configuration due toheat, friction or pressure.

Mis-match. Improper association of two or more parts.

Mis-positioned. Improperly installed part which maydamage the installed part or two associated parts. Also:mis-aligned, reversed.

Nick. A sharp surface indentation caused by impact of aforeign object. Parent material is displaced, seldomseparated.

Out-of-round. Part with inconsistent diameter.

Out-of-square. Part with deformation of right anglerelationship between part surfaces.

Peeling. A breaking away of surface finishes such ascoatings and plating. Peeling would be flaking of largepieces. A blistered condition usually precedes oraccompanies peeling. Also: blistered, flaked.

Pick-up. A transfer of metal from one surface to another.Usually the result of rubbing two surfaces togetherwithout sufficient lubrication.

Pit. A small irregular shaped cavity in the surface of theparent material usually caused by corrosion, chippingor electrical discharge.

Plugged. Totally or partially blocked pipe, hoses, tubing,channelling or internal passages. Also: clogged,obstructed, restricted.

Porous. State of material caused by internal voids. Usuallyapplied to cast material or welds.

Rolling-over. Lipping or rounding of a metal edge. Also:lipped, turned.

Rubbed. Moved with pressure or friction against anotherpart.

Rupturing. Excessive breaking apart of material usuallycaused by high stresses, differential pressure, locallyapplied force or any combination of these. Also: blown,burst, split.

Score(s). A deep scratch or scratches made by sharp edgesof foreign matter.

Scratches. Light narrow, shallow mark or marks caused bymovement of a sharp object or particle across a surface.Material is displaced, not removed.

Seized. Parts bound together. May be due to expansion orcontraction due to high or low temperature, foreignobject jammed in mechanism or lack of lubricant. Also:frozen, jammed, stuck.

Sheared. Body divided by cutting action. Also: cut.


Spalled. Sharply roughened area characterized byprogressive chipping-away of surface material. Not tobe confused with flaking.

Stretching. Enlargement of a part. May result fromexposure to operating conditions or excessive force.Also: growth.

Stripping. A condition usually associated with fastenerthreads or electrical insulation. Involves removal ofmaterial by force.

Torn. Separated by pulling apart.

Worn. Consumption of material of a part as a result of use.

2. HUMAN FACTORS TERMS

This section presents a selection of Human Factors termswhich are likely to be encountered when writing the FinalReport on an accident. Knowledge of these terms willfacilitate the identification and formulation of the HumanFactors aspects which were present in the accident.

HUMAN FACTORS

Acute fatigue. The result of excessive physical and/ormental activity during a short period. A temporarycondition that may be reversed by adequate rest.

Channelized attention. A mental state which exists when aperson’s full attention is focused on one stimulus to theexclusion of all others. This becomes a problem whenthe person fails to perform a task or processinformation of a higher priority and thus fails to noticeor has no time to respond to cues requiring immediateattention.

Chronic fatigue. The result of long exposure to successiveperiods of acute fatigue, over many days or weeks,without adequate rest periods for recovery.

Cockpit authority gradient. The relative skills andexperience in a particular environment that are factorsin determining the extent of the pilot’s authority.

Cognitive saturation. The information to be processedexceeds an individual’s span of attention.

Complacency. A state of reduced conscious attentioncaused by a sense of security and self-confidence.

Behaviour characteristics of complacency includeoverconfidence and boredom, both of which cansignificantly degrade performance.

Confirmation bias. An expectation of an event maydiminish an individual’s ability to recognize evidencethat events are not developing as anticipated.

Distraction. The interruption and redirection of attention byenvironmental cues or mental processes.

Fascination. An attention anomaly in which a personobserves environmental cues, but fails to respond tothem.

Fatigue. The progressive decrease in performance due toprolonged or extreme mental or physical activity, sleepdeprivation, disrupted diurnal cycles, or life eventstress.

Habit pattern interference. Behaviour in which the subjectreverts to previously learned response patterns whichare inappropriate to the task at hand.

Illusion. An erroneous perception of reality due tolimitations of sensory receptors and/or the manner inwhich the information is presented or interpreted.

Inattention. Inattention is usually due to a sense of security,self-confidence or perceived absence of threat.Boredom is a form of inattention due to anuninteresting and undemanding environment.Complacency is another form due to an attitude ofoverconfidence, laxity or lack of motivation.

Pressure. A type of stress resulting from the demands ofmanagement, peers, self-induced goals, time,environmental factors or man-machine relationship.

Situational awareness. The ability to keep track of theprioritized significant events and conditions in theenvironment of the subject.

Spatial disorientation. Unrecognized, incorrect orientationin space.

Stress. Mental or physical demand requiring some action oradjustment.

Vigilance. Maintenance of the appropriate level ofconscious attention for the assigned task. Lapses inattention may occur after a person has been at amonitoring task for a period of time.


Appendix 5 to Chapter 1COMMONLY USED FINDINGS

The following findings might be used in aviation accidentreports and are presented here as examples only. Theinvestigator-in-charge must ensure that each finding in anaccident report is pertinent, valid and in the proper context.

1. AIRCRAFT

— The aircraft was certified, equipped and maintainedin accordance with existing regulations andapproved procedures.

— The aircraft had a valid Certificate of Airworthinessand had been maintained in compliance with theregulations.

— The maintenance records indicated that the aircraftwas equipped and maintained in accordance withexisting regulations and approved procedures.

— The aircraft was airworthy when dispatched for theflight.

— The mass and the centre of gravity of the aircraftwere within the prescribed limits.

— There was no evidence of any defect or malfunctionin the aircraft that could have contributed to theaccident.

— There was no evidence of airframe failure or systemmalfunction prior to the accident.

— The aircraft was structurally intact prior to impact.

— All control surfaces were accounted for, and alldamage to the aircraft was attributable to the severeimpact forces.

— The aircraft was destroyed by impact forces and apost-impact fire.

— Due to the destruction of the aircraft by the impactand fire, it could not be determined whether anypre-impact failure or system malfunctioncontributed to this accident.

— The destruction of the aircraft by impact and fireprecluded determination of any material failure orsystem malfunction.

— The position of the fuel selectors could not bedetermined due to the extensive fire damage.

— The fuel sampled was of the proper grade andquality, and contained no contamination.

— The fuel that remained in the aircraft fuel tanks wasuncontaminated and of the recommended grade.

— The engine(s) stopped from fuel exhaustion (nousable fuel on board).

— The engine(s) stopped from fuel starvation (usablefuel on board).

— The intercom system, flight deck lighting and otherstandby electrical services failed some four minutesbefore impact as a result of a rapid decay in batterypower for which no explanation was found.

— The obsolescent design of the aircraft’s primaryflight instruments and radio navigation systemscontributed to the loss of situational awareness ofthe crew at a time of high crew workload.

— The worn condition of the left tire reduced brakingeffectiveness in the wet runway conditions.

— Propeller blade damage and twist was consistentwith the engine producing power at impact.

— The propeller(s) exhibited chord-wise scratchingand torsional damage indicative of the engineproducing power at impact.

2. CREW/PILOT

— The flight crew/pilot/co-pilot was licensed andqualified for the flight in accordance with existingregulations.


— The flight crew/pilot/co-pilot was properly licensed,medically fit and adequately rested to operate theflight.

— The flight crew/pilot/co-pilot was in compliancewith the flight and duty time regulations.

— Although the aircraft was equipped for instrumentflight, the pilot was not qualified for IFR flight.

— The pilot’s degraded performance was consistentwith the effects of fatigue, but there was insufficientevidence to determine if the pilot’s degradedperformance contributed to the accident.

— Although the pre-flight rest period was adequateand the flight duty time was within the companyflight time limitations, the two-hour turnaround inthe middle of the night may have reduced thealertness levels of the two pilots.

— The pilot’s actions and statements indicated thathis/her knowledge and understanding of the aircraftsystems was adequate/inadequate.

3. FLIGHT OPERATIONS

— The flight was conducted in accordance with theprocedures in the company Operations Manual.

— The flight crew carried out normal radiocommunications with the relevant ATC units.

— The pilot attempted to continue visual flight ininstrument meteorological conditions.

— There was insufficient height available to effect arecovery from the stall.

— During (phase of flight), the aircraft began anuncommanded turn to the right/left.

— During flare for touchdown, the pilot lost control ofthe aircraft in a strong gust of wind.

— The aircraft was fitted with a radio altimeter, but theoperator’s procedures did not require reference to itduring non-precision approaches.

— The wind conditions in which the pilot landed theaircraft were outside the limits detailed in the FlightManual and the Operations Manual.

— Braking performance analysis indicated that, in theconditions existing at the time of the accident, theaircraft could not have stopped on the runwayavailable.

— The incorrect handling of the airframe de-icingsystem resulted in a considerable accretion of ice orsnow during the descent.

— The continuation of the landing with the airspeedabove the calculated threshold speed resulted intouchdown beyond the normal touchdown point.

— The pilot made an early decision to divert towardsa suitable aerodrome while attempting to determinethe extent of the emergency.

4. OPERATOR

— The presentation of the operator’s EmergencyChecklist was inadequate for use under conditionsof stress.

— The Standard Operating Procedure for the non-handling pilot to monitor the progress of theapproach was not effective in preventing the pilotflying the aircraft from descending below thepublished approach profile.

— The operator’s Quality Assurance system had notidentified frequent deviations from therequirements of the Aircraft Maintenance Manualover a considerable period of time.

— The Crew Resource Management training arrangedby the operator did not promote good flight deckcommunication.

5. AIR TRAFFIC SERVICES ANDAIRPORT FACILITIES

— The approach/approach radar controllers wereproperly licensed, medically fit and correctly ratedto provide the service.


— The number of air traffic controllers on duty in thetower was (not) in accordance with the regulations.

— The air traffic controller’s workload was assessedas low/moderate/high with normal complexity.

— The air traffic controller gave conflicting clearancesto the two aircraft.

— The air traffic controller issued a clearance to ...(flt #) which caused a loss of separation to anotheraircraft (flt #).

— The air traffic controller requested (flt #) to (turn,climb, descend) immediately to avoid traffic.

— ATC provided prompt and effective assistance tothe flight crew.

— Use of incorrect RT terminology by the flight crewwhen declaring the emergency negated an effectiveresponse from ATC.

— All aerodrome approach aids and lighting facilitieswere operating normally at the time of the accident.

— The airport was not equipped with a facility torecord the Secondary Surveillance Radar. The lackof data significantly impaired the reconstruction ofthe aircraft’s descent profiles, given the limitedinformation available from the FDR fitted to theaircraft.

6. FLIGHT RECORDERS

— The aircraft was not equipped with a flight datarecorder (FDR) or a cockpit voice recorder (CVR);neither was required by regulation.

— The 30-minute closed loop cockpit voice recordertape was of inadequate duration to be helpful in theinvestigation of this accident.

— The lack of a CVR recording covering the period ofthe incident prevented some details of the eventsfrom being resolved.

7. MEDICAL

— There was no evidence that incapacitation orphysiological factors affected the flight crewperformance.

— There was no evidence that the pilot suffered anysudden illness or incapacity which might haveaffected his/her ability to control the aircraft.

— Toxicological tests for common drugs/ carbonmonoxide/ hydrogen cyanide were negative/positive.

— Based on the autopsy, toxicology, and medicalreports, there was no evidence to indicate that thepilot’s performance was degraded by physiologicalfactors.

— A post-mortem examination of the pilot showedthat the cause of death was a coronaryatherosclerosis/hypertensive heart disease.Toxicological results were negative for carbonmonoxide, cyanide, volatiles and tested drugs.

— The flight crew was diagnosed as suffering fromcarbon monoxide (CO) exposure.

— A toxicology report revealed 0.180 per cent alcoholin the pilot’s blood. The specimen was taken onehour and 12 minutes after the accident.

8. SURVIVABILITY

— The accident was not survivable due to themagnitude of the deceleration forces and theseverity of the post-impact fire.

— The occupants succumbed to the effects of the post-impact fire.

— Although a shoulder harness was available, the pilotdid not wear it.

— The fatal injuries sustained by the occupants mighthave been prevented had they worn shoulderharnesses.

9. SAFETY OVERSIGHT

— The civil aviation authority’s safety oversight of theoperator’s procedures and operations was adequate/inadequate.

— The civil aviation authority’s safety oversightprogramme had not addressed the subject of thediverse nature of the operator’s fleet of aircraft, in


terms of the primary flight instruments, navigationequipment, flight deck layout and its suitability forpublic transport operations.

— The safety oversight programme conducted by thecivil aviation authority on this operator hadidentified deficiencies in the Crew Resource

Management aspects of the company’s operations.However, the oversight programme was ineffectivein producing sufficient and timely improvement.

— The civil aviation authority’s monitoring systemhad been ineffective in identifying and making theoperator correct the procedural lapses.

Chapter 2

THE ACCIDENT/INCIDENT DATA REPORTING(ADREP) SYSTEM

2.1 REPORTS

2.1.1 In accordance with Annex 13, States report toICAO information on all aircraft accidents which involveaircraft of a maximum certificated take-off mass of over2 250 kg. ICAO also gathers information on aircraftincidents considered important for safety and accidentprevention. Thorough accident and incident investigationsidentify safety issues in the aviation system, both at theairline level and at the national level. However, it issometimes difficult to differentiate between isolatedmanifestations of a problem and systemic unsafe conditionswith a potential for loss of life or property damage. Suchsafety issues must be validated; in part, this is done bycomparing the accident and incident experience in questionwith the broader experience of the airline, the State andother States. This type of comparative analysis requiresreliable and complete data. The Accident/Incident DataReporting (ADREP) System operated by ICAO providesStates with the data that will assist them in validating safetyissues. Based on this validation process with its attendantassessment of risk, accident investigation authorities canoffer meaningful recommendations for correcting unsafeconditions in the aviation system.

2.1.2 Detailed information concerning the reportingof accidents and incidents to the ADREP system iscontained in the ICAO Accident/Incident Data Reporting(ADREP) Manual (Doc 9156).

2.2 ADREP INFORMATION AVAILABLETO STATES

2.2.1 When ADREP reports are received from States,the information is checked and stored in a computer. Thestored reports constitute a database of worldwideoccurrences in order to provide States with the followingservices:

a) a bi-monthly summary of reports received,containing information on occurrences which havebeen reported to ICAO during the preceding two-month period, and providing States with up-to-dateinformation on significant occurrences on aworldwide basis;

b) annual ADREP statistics, presenting statisticalinformation under broad categories, such as thetypes of events which took place and the phases ofoperation in which they occurred;

c) replies to States’ requests for specific information.States requesting information for specific safetyproblems should forward to ICAO a request forinformation outlining the problem under study.Replies may be sent using e-mail, facsimile, courieror mail depending on the urgency of the request andthe amount of data to be sent; and

d) a record for individual States. ICAO may provideany State, upon its request, with the completerecord of accidents and incidents reported by thatState to ICAO, and thus serve as an occurrencedatabase for those States which wish to takeadvantage of this service.

2.2.2 The ICAO ADREP database of accident andincident information is used to provide States with flightsafety information. States’ administrations are encouragedto request ADREP information from ICAO in order toassist them in their accident or incident investigation andprevention efforts. For example, if it is suspected in aninvestigation that a specific malfunction or failure hasoccurred, information on similar occurrences may behelpful in the investigation. ADREP information is alsoused by States for accident prevention studies, includingthose prompted by operators, manufacturers and safetyorganizations. Printouts are provided by ICAO with theunderstanding that the ADREP information will be used foraccident prevention only.

IV-2-1


2.2.3 In 2003, the ADREP database contained 28 000reports, of which 18 000 were Accident/Incident DataReports. Fifty-one per cent (51%) of the reports concernedairline operations and forty-nine per cent (49%) weregeneral aviation. Seventy-five per cent (75%) wereaccidents and twenty-five per cent (25%) were incidents.

2.3 DATA VALIDITY

2.3.1 The validity of the safety information whichICAO provides to States depends on the detail and carewith which accidents and incidents have been investigatedand reported to ICAO. Thus, it is in the interest of all Statesto accurately report all investigated occurrences inaccordance with Annex 13. Only then can ICAO providevalid and complete information required for accidentprevention.

2.4 PRELIMINARY REPORT(ADREP FORM P)

2.4.1 Basic factual and circumstantial information onan accident is usually available within the first two to fourweeks of the investigation. The Preliminary Report form isa simple and standard method for reporting suchpreliminary information. In accordance with Annex 13,when the aircraft involved in an accident is of a maximummass of over 2 250 kg, the Preliminary Report shall be sentby the State conducting the investigation to:

a) the State of Registry or the State of Occurrence, asappropriate;

b) the State of the Operator;

c) the State of Design;

d) the State of Manufacture;

e) any State which provided relevant information,significant facilities or experts; and

f) ICAO.

2.4.2 When the aircraft involved in an accident is ofa maximum mass of 2 250 kg or less, and whenairworthiness or matters considered to be of interest toother States are involved, the State conducting the

investigation should forward the Preliminary Report to thesame States as above, but excluding ICAO.

2.4.3 The Preliminary Report shall be sent by airmailwithin thirty days of the date of the accident unless theAccident/Incident Data Report has been sent by that time.When matters directly affecting safety are involved, it shallbe sent as soon as the information is available and by themost suitable and quickest means available.

2.4.4 An example of a completed Preliminary Report(ADREP Form P) can be found in Doc 9156.

2.5 ACCIDENT DATA REPORT(ADREP FORM D)

2.5.1 When the investigation has been completed andthe Final Report has been released, the Accident DataReport is to be compiled. The purpose of the Accident DataReport is to provide a standard method for reportingaccurate and complete information on an accident,including factors (causes) and safety recommendations. Inaccordance with Annex 13, the Accident Data Report is tobe sent to ICAO by the State conducting the investigationof an accident involving an aircraft of a maximum mass ofover 2 250 kg.

2.5.2 If, at the end of the investigation, it isestablished that some of the data in the Preliminary Reportwas not correct or was incomplete, this should be reflectedin the Accident Data Report. When ICAO receives theAccident Data Report, the Preliminary Report informationwill be updated. Similarly, if a State re-opens aninvestigation, the information previously reported shouldbe amended by a new report.

2.5.3 If an accident investigation has been completedand the Accident Data Report can be compiled within thirtydays of the date of the accident, the State conducting theinvestigation should send an Accident Data Report toICAO, instead of a Preliminary Report. In such cases, thisState should also send the Data Report to the States whichnormally would have received the Preliminary Report.

2.6 INCIDENT DATA REPORT(ADREP FORM D)

2.6.1 Accident investigations have frequently broughtto light previous incidents which were dismissed as

Part IV. ReportingChapter 2. The Accident/Incident Data Reporting (ADREP) System IV-2-3

insignificant at the time of their occurrence. The knowledgeacquired in retrospect from the accident investigations hasdemonstrated that these incidents, if properly investigated,could have provided the basis for remedial action, whichmight have prevented the accident. Therefore, it is highlydesirable that incidents be investigated and the reports begiven the same worldwide release as accident reports.

2.6.2 In accordance with Annex 13, if a Stateconducts an investigation into an incident to an aircraft ofa maximum mass of over 5 700 kg, that State shall send, assoon as is practicable after the investigation, the IncidentData Report to ICAO.

2.6.3 If a State has found an incident significantenough to carry out an investigation, it is likely that safetymatters are involved and it is therefore important thatICAO receive the relevant information. The types ofincidents which are of main interest to ICAO for accidentprevention studies are listed in an Attachment toAnnex 13.

2.6.4 An example of a completed Accident/IncidentData Report (ADREP Form D) can be found in Doc 9156.

2.6.5 Copies of the Preliminary Report and theAccident/Incident Data Report shall be sent to ICAO,addressed as indicated in Chapter 1, 1.8.

2.7 CONSTRAINTS ON INCIDENTDATA REPORTS

2.7.1 Considering the sensitivity related to thedissemination of incident information, the followingconstraints are placed upon the use of incident data byICAO:

a) ICAO will use incident information for the purposeof accident prevention only;

b) when ICAO conducts analyses based on incidentinformation, it will be identified as such; and

c) ICAO will de-identify incident reports before theirdissemination, by deletion of the State of Registry,the nationality and registration marks, and the nameof the owner and operator.

— END —

© ICAO 20035/03, E/P1/2000

Order No. 9756P4Printed in ICAO

Documents

50ff3ff2-ecd8-4f88-b84c-467c0a0101be-9756_p4_cons_en