Spanair Flight JK5022 Accident involving aircraft

MINISTERIO DE FOMENTO

COMISIÓN DE INVESTIGACIÓN DE ACCIDENTES E INCIDENTES DE AVIACIÓN CIVIL

Spanair Flight JK5022

Accident involving aircraft McDonnell Douglas DC-9-82 (MD-82), registration EC-HFP, operated

by Spanair, at Madrid-Barajas airport on 20 August 2008

ESASI, Amsterdam19-20 April 2012



1. History of the flight2. The relevant data3. Investigation challenges4. Design aspects. Take Off Warning System

(TOWS) 5. Overview of maintenance factors analysis6. Overview of operational factor analysis

SUMMARY



HISTORY OF THE FLIGHT (4/4)

G:\ESASI\Spanair 5022.avi



• The physical evidences. Flaps/slats– Wing control surfaces and associated elements.

Flaps/slats– Flaps/slats control lever– Slats indication lights– DFDR data – CVR data

• The TOWS failure – CVR data

THE RELEVANT DATA



• Several flap actuators were recovered.Each was extended by a differentamount.

• In the case of the right outboard flap, itsinboard actuator was extended fiveinches and the central actuator 1.1inches.

• The flaps were easily extended andretracted, making it impossible todetermine the position they had on theaircraft.

WING CONTROLSURFACES AND ASSOCIATEDELEMENTS

FLAPS/SLATS



WING CONTROLSURFACES AND ASSOCIATEDELEMENTS

FLAPS/SLATS

SLATS DRUM ACTUATORS

The part of the piston that wasextended was not covered in soot.The actuators were not blocked andcould be moved freely.

TRACKS FOR THE NOS. 0 AND 1SLATS PANELS ON THE LEFT SIDE.They were found locked in the fullyretracted position.



THE LEFT STUB ON THE FLAPS LEVER WAS CONSIDERABLY DEFORMED.

THE SLOT CORRESPONDING TO THE UP/RET POSITION ON THE FIXED FLAPS GUIDE HAS A MARK THAT CORRESPONDS TO THE DAMAGE MADE BY THE LEVER STUB.

FLAPS/SLATS CONTROL LEVER



FLAPS/SLATS CONTROL LEVER & SLATS INDICATION LIGHTS

Take off condition-CG/flaps selectionindication panel

Flaps/Slatscontrol lever

Slats indicationlights



DFDR DATA FLAPS DEFLECTION

Second taxi and takeoff was with flapsetting 0º.

FDAUFlight Data Acquisition

Unit

DFDRFlight Data

RecorderDFGC

Flap sensor

Slat sensor

Flaps sensors send info directly FDAUSlats sensors send info to DFGC and then to FDAU. A problem in bus connecting DFGC and FDAU prevented torecord Slat parameter in DFDR.



CVR DATA TOWS

Throughout the takeoff run and until the end of the CVR recording, no sounds were recorded coming from the Takeoff Warning System (TOWS).



1. Flaps and slats remain retracted during takeoff which it is a non approved configuration.

2. Crew did not actuate flap/slat control lever.

3. TOWS failed to provide a warning to the crewof the improper aircraft configuration.

FINDINGS



WHY1 did not TOWS work?

2 did not crew select and verify flap/slat position in spite of having procedures and checklistsintended to?

AND3 Were there any previous conditions that might

have prevented the accident?

INVESTIGATION CHALLENGES

DESIGN ASPECTS

OPERATION ASPECTS

MAINTENANCE ASPECTS



• The relationship between the TOWS and the RAT probe. The R2-5 relay

13

DESIGN ASPECTS. TOWS FAILURE

Z‐29Breaker

Ram Air Temperature (RAT) Probe

Heater

AC Power

Thrust Rating Panel (TRP)

R2‐5 Relay

Section “C”

Section “D”

Section “B”

Section “A”

K‐33Breaker

AC Power Ground‐Flight SwitchesLanding GearCoil

TOWS



DESIGN ASPECTS. TOWS FAILURE

14

Comparison between the recovered relay R2-5 and a new one of the same model

R2-5 operation diagram

The R2-5 relay

Groundcondition

Flight condition



• Data from five MD-80 operators• Sampling of over 100 airplanes spanning 15 years

DESING ASPECTS. TOWS FAILURE.THE R2-5 RELAY.

High RAT probe temperature. Cases involving other MD operators

Cases compiled byBoeing (2000-2008)

REPLACEMENT R2-5 RELAY

(80%)



Functional test of R2-5 relay• Reference to Leach and Boeing specifications• The results did not reveal any defect

CT scan• Performed at ZEISS facilities in Aalen (Germany)• No abnormalities found in internal components in

this exam

Comparison between the recovered relay R2-5 and a new one of the same model

DESING ASPECTS. TOWS FAILURE.R2-5 RELAY INSPECTION.



DESING ASPECTS. TOWS FAILURE.R2-5 RELAY TEARDOWN.



Design aspects. Conclusions

• R2-5 findings

Given the importance of the R2-5 relay to the operation of theTOWS, an evaluation should be conducted of the relay’s operatingconditions, its real service life, its reliability and its failure modes.Specific maintenance instructions should be defined for thiscomponent based on the findings of said evaluation.



• TOWS in airplanes of the MD-82 generation

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TOWS design should be reviewed in MD-82 generation airplanes.The goal of this review should be to require that the TOWScomply with the applicable requirements for critical systemsclassified as essential in CS 25.1309 and FAR 25.1309.



• Certification of TOWS systems

20


Regulations CS-25 and FAR 25 should be revised to add a requirement that ensures that TOWS are not disabled by a single failure or that they provide the crew with a clear and unequivocal warning when the system fails.

Guidelines and the clarifying material for the CS-25 and FAR-25 regulations should consider the human errors associated with faults in takeoff configurations when analytically justifying the safety of the TOWS, and to analyze whether the assumptions used when evaluating these systems during their certification are consistent with existing operational experience and with the lessons learned from accidents and incidents.



Local conditions• There was another airplane ready for replacement of

aircraft if deemed necessary.• Self-induced pressure for mechanic:

People on board waiting to departure after a delay.High temperatures inside the cabin.Ground assistance and flight crew waiting for adecision from maintenance (replace or not theaircraft).

• The MEL was available on board

Overview of maintenance factors analysis



• Individual actions– AMM was not consulted– Maintenance personnel performed an incomplete analysis of

the RAT probe heater malfunction on the ground.

• Maintenance personnel actuation analysis1. To place more importance on the most immediate

information available 2. To adopt only a few theories3. Once a theory is adopted, they tend to look for evidence to

support it and reject information contrary to it.


Tunnel vision phenomenon



MINIMUM EQUIPMENT LIST (MEL) CONCERNS

• Go straight to MEL looking for alleviation is not restricted byrules but is not in line with good maintenance practices.

• MEL is usedAs first option to try to dispatch an aircraft in detriment ofa troubleshooting and/or malfunction correction.Under conditions of dispatch pressure and few time tomake a decision.




• MMEL should be modified in items that may be related to RATprobe heating on the ground so that said items includemaintenance (M) and/or operating (O) instructions to check theTOWS.

• Troubleshooting contained in AMM only consider the case inwhich the heating system does not supply heat to the RATprobe in flight.

Maintenance aspects. Conclusions



According to factual information:

1. CHECKLISTS. Spanairchecklists didn’t requireTOWS to be checked prior toevery flight.

2. CRM. There were severaldeviation from the SOP’s.

3. STALL RECOVERYPROCEDURE. Crew didn’tidentify aircraft stall.

Overview of operational factors analysis



1. There were differences between Boeing FCOMand Spanair OM.

2. Nobody (authority, operator, audits) noticedthose differences, so the TOWS wasn’t checkedprior every flight according to Spanairprocedures.

SOP’s. CHECKLISTS (1/6)




1. National authorities in Europe only accept thechecklists. They aren’t required to approvethem. It isn’t clear how in-depth it should bethe assessment to accept checklists (therearen’t guides).

2. It is not required the operators to have aprocedure for controlling the changes inchecklists. There aren’t any guidance materialfor the preparation or modification ofchecklists.





The Spanair checklists didn’t follow the bestcriteria related to the design of checklist.



14.12.08 “After start” checklistThe item to check the flaps/slats was omitted. We can hear on the CVR “Ask for taxi..” when first officer is about to read the item 9, the last one.



STOWEDEIGHT, ELEVEN

ALIGNED

ELEVEN


SOP’s. CHECKLISTS (4/6)14:22:06 “Takeoff Imminent” checklist Final items reading by the first officer: “FINAL ITEMS, WE HAVE, SORRY…



1. Best criteria to design and modify checklistsshould be known by everybody.

2. Regulation and guidelines should bedeveloped for both, European authorities andoperators, related to the design andmaintenance of checklists.





• Guidance material should be drawing up for thepreparation, evaluation and modification ofchecklists associated with normal, abnormal andemergency procedures that is based on the criteriathat govern safety management systems.

Operational aspects. Conclusions.




CREW RESOURCE MANAGEMENT (1/3)

The circumstances of the accident revealed theexistence of several factors potentially related toknowledge and training deficiencies resulting in humanerrors:

stress induced by operational pressures,hurry-up,lack of coordination among crew members,lack of assertiveness,channelized attention,expectation bias,procedural adherence




1. Captain and first officer received initial and recurringCRM training according to regulation.

2. Line Checks by the authority and operationalassessments didn’t reveal any weaknesses related toCRM.

3. There is a mismatch between the improper CRM observedin the accident and the efforts expended in the area ofCRM. We should ask:

4. Proper training for inspectors.





•Research or studies should be conducted aimed to assesshow the requirements involving crew resource management(CRM) in the European Union are applied and theireffectiveness. The results of these studies should reveal theweaknesses that exist in this area and yield proposals forcorrecting them.

•Regulatory initiatives should be undertaken intended torequire commercial public transport operators to implementa program of line operations safety audits (LOSA), as part oftheir accident prevention and flight safety programs.





Just after take off, the stick shaker and stall auralwarning activated.• The crew didn’t recognized the stall condition.• So, they didn’t apply the stall recovery

procedure, although the stall recoveryprocedure didn’t include the flap/slat levercheck.

STALL RECOVERY PROCEDURE (1/3)




1. The need to train takeoff stalls has emerged asa constant from most significant accidentsrelated to improper takeoff configuration.

2. Include a check of flap/slat lever in the stallrecovery procedure is key for an effectiverecovery.

3. Simulator are capable of emulating stallconditions.





•Takeoff stall recovery should be part of initial andrecurring training programs of pilots.

•The stall recovery procedure in the (AFM) of largetransport airplanes should include a check of theflap/slat lever and its adjustment.

•Requirements should be established for flightsimulators so as to allow simulator training to coversustained takeoff stalls that reproduce situations thatexceed those included in the flight envelope.





THANK YOU VERY MUCH FOR YOUR ATTENTION

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Spanair Flight JK5022 Accident involving aircraft