ACRP 4-01ACRP 4-01Aircraft Overrun and Undershoot Analysis for Runway Safety Areas

Manuel Ayres, Ph.D.

SummarySummary

Objective Approach Functional Hazard Analysis Accident/Incident Database Normal Operations Data Normalization Risk Models Analysis Software

ACRP 4-01 ProjectACRP 4-01 Project Airport Cooperative Research Program (ACRP) Objective: develop near-term practical solutions to problems faced by

airports Industry-driven program focused on applied research to airport operators Authorized in December 2003 as part of the Vision 100-Century of

Aviation Reauthorization Act Oct 2005, FAA executed a contract with the National Academies

(through TRB) to serve as manager of the ACRP Program oversight and governance are provided by representatives of

airport operating agencies

http://www.trb.org/crp/acrp/acrp.asp

Project TeamProject Team ARA Team

ARA Jim Hall – PI Manuel Ayres – PM Rich Speir Hamid Shirazi Tara Puzin Other

Loughborough University David Pitfield Robert Caves Andrew Appleyard Derek Wong

ESR-Technology Mark Eddowes

ACRP Staff Responsible Michael R. Salamone, CM

BackgroundBackground

71% of Accidents occur during landing and take-off 41% of onboard and 3rd party fatalities Landing overruns, landing undershoots, take-off

overruns, and crashes after take-off Runway safety areas (RSA) are prescriptive resulting

in ‘averaged’ degrees of protection Current RSA dimensions based on studies by FAA in

the 80s

Reason’s Swiss CheeseReason’s Swiss Cheese

Hazards

Holes are active failures & latent conditions

Successive layers of defenses, barriers and Safeguards

Accidents/ Incidents

The cheese is moving!

Objective of ACRP 4-01Objective of ACRP 4-01

Collect historical information related to overrun and undershoot accidents and incidents

Develop risk models for overrun and undershoot events

Evaluate risks associated with standard and non-standard RSA dimensions

Develop prototype software for overrun and undershoot risk analysis

Functional Hazard AnalysisFunctional Hazard Analysis

Formal and systematic process for the identification of hazards (similar to hazard and operability (“HAZOP”) studies)

Gathering together a multi-disciplinary team Determine relevant causal factors of overrun and

undershoot accidents and hazards to aircraft associated with airport operations

Support the data collection and development of risk models

Functional Hazard AnalysisFunctional Hazard Analysis

CategoriesAircraft characteristics and system faultsAirport characteristics and system faultsWeather characteristicsPilot related issues

Landing Overruns – Major FactorsLanding Overruns – Major Factors

Weather Tailwind Cross wind Visibility Ceiling

Airport Surface contaminants and friction (water, snow, ice, rubber

deposits) Pilot

Landing long Landing high Landing fast

Aircraft System faults

Takeoff Overruns – Major FactorsTakeoff Overruns – Major Factors

Weather Tailwind

Airport Surface contaminants and friction (water, snow, ice,

rubber deposits) Pilot

Delay to abort Aircraft

System or component malfunction require to abort takeoff

Landing Undershoots – Major FactorsLanding Undershoots – Major Factors

Weather Visibility Ceiling Wind variations (gusts, shear)

Airport Surface contaminants and friction (water, snow, ice,

rubber deposits) Pilot

Visual illusion

Visual IllusionVisual Illusion

Runway dimensions Runway and terrain slope Intensity of runway lighting Visibility Wet runway Crosswind

Source: David Newman and Flight Safety Foundation

A B

Other FactorsOther Factors Wind variations (gusts, shear) Temperature, Altitude Landing/Takeoff Distance (LDA vs. LDR; ASDA vs. ASDR) Slopes (longitudinal and transverse) Runway profile System faults Unstabilized approach “Press-on-itis” Incorrect (delay) application of thrust reverse, spoilers and brakes ‘Over-consideration’ for comfort Incorrect interpretation of reported operation conditions Selecting wrong runway Weight Availability of navigational aids Approach too low Attempt to land too close to arrival end of the runway

Database SourcesDatabase Sources

NTSB Accident Database & Synopses (Accidents and Incidents)

FAA Aviation Safety Reporting System - ASRS (Incidents) Accident/Incident Data System - AIDS (Incidents)

Transportation Safety Board of Canada (Accidents & Incidents) UK CAA-Safety Regulation Group (SRG) Mandatory Occurrence

Reporting Scheme (MORS) Database (Accidents & Incidents) Australian Transport Safety Bureau (Accidents & Incidents)

DATA CollectionDATA Collection

Cost of Investigation& Availability of

InformationCo

nse

que

nce

s

Accidents

Incidents

# Reported EventsProbability and# of Events

Database FiltersDatabase Filters

Both accidents and incidents North American, Western European, Australia, New

Zealand Fixed-wing Part 121, 125, 129, 135 and Part 91F Operations Aircraft with MTOW > 12500 lb Excluded single engine and piston engine aircraft

Access Database

• ~ 300 fields/record• Basic Data• Aircraft Data• Airport Data• Consequences• Details

• Flight Data• Obstacles• Terrain• Injuries• Weather• Wreckage

Accident LocationAccident LocationAccident LocationAccident Location

y

x

Wreckage Location

Summary TableSummary Table

Database Landing Overruns

Take-off Overruns

Landing Undershoots

FAA Accident/Incident Data System (AIDS)

13 (only incidents)

3 (only incidents)

21 (only incidents)

Aviation Safety Reporting System (ASRS)

87 (only incidents)

7 (only incidents)

13 (only incidents)

NTSB Accident Database & Synopses

226 (only accidents)

166 (only accidents)

65 (only accidents)

Transportation Safety Board of Canada

21 (accidents and incidents)

4 (accidents and incidents)

2 (accidents and incidents)

UK CAA-SRG MORS 26 (accidents and incidents)

6 (accidents and incidents)

Total (so far) 373 186 101 Grand Total (so far) 628

Normal Operations DataNormal Operations Data

Approach Evaluate number of operations that experience

certain factors benignly, singly and in combination. Generate risk ratios and quantify the importance of

risk factors Source: FAA's Enhanced Traffic Management System

Counts (ETMSC) & a National Oceanic and Atmospheric Administration's (NOAA) weather database

Normal Operations DataNormal Operations Data

NOD was sampled from a total of 78 selected airports Sampled airports account for 48,924,040 operations

from 2000 to 2005 inclusive (25.5% of all relevant traffic in the period)

Flights on the first day of February, May, August and November of 2002, 2003 and 2004 were sampled to constitute the NOD sample

After eliminating incompatible traffic, the final NOD sample consists of 24,240 flights

NormalizationNormalization

Small pool of relevant data available Data from different airports, operation conditions,

aircraft performance Comparing apples and apples Only raw distances between the final wreckage

location and the runway end have been used to develop current RSA recommendations

Assume an infinitely long hard surface runway

Normalization ProceduresNormalization Procedures

Correcting (overrun and undershoot) distances for Temperature Altitude Slope (when available) Aircraft performance Landing/Takeoff distance available Terrain (type, slope)

Risk ModelsRisk Models

Frequency Location Severity (Injuries, Cost)

Landing overrun Takeoff overrun Landing undershoot

Risk ModelsRisk Models

Three-Part Risk Model

Accidentprobability

model

Locationprobability

model

Accidentconsequences

model

Operationconditions

(accident and NOD data)

Operation conditions, terrain

Operation conditions, obstacles and terrain

Risk

Three-Part Risk Model

Accidentprobability

model

Locationprobability

model

Accidentconsequences

model

Operationconditions

(accident and NOD data)

Operation conditions, terrain

Operation conditions, obstacles and terrain

Risk

Frequency ModelsFrequency Models

Probability = Ni/a / Nn (under certain operation conditions)

P{Accident_Occurrence} is the probability (0-100%) of an accident type occur given certain operational conditions.

Xi = f(runway friction, ceiling, visibility, crosswind, tailwind, etc.)

...33221101

1}_{

XbXbXbbeOccurenceAccidentP

Location Model - OverrunsLocation Model - Overruns

RSA

naxexLocationP }{

mbyeyLocationP }{

x

y

Stop LocationProbability Distribution

Location Model - OverrunsLocation Model - Overruns

RSA

Frequency Contours

Decreasing Probability

Location Model - UndershootsLocation Model - Undershoots

RSA

naxexLocationP }{

mbyeyLocationP }{

x

y

Touchdown LocationProbability Distribution

Consequences ModelConsequences Model

Distance to Obstacle

Probability of Occurrence

Operation Conditions

Consequences Model

Type, Size of Obstacle

InjuryDamage

Terrain

High

Medium

Low

Distance to Obstacle

Probability of Occurrence

Operation Conditions

Consequences Model

Type, Size of Obstacle

InjuryDamage

Terrain

High

Medium

Low

High

Medium

Low

Prototype Analysis SoftwarePrototype Analysis Software

User-friendly application in Visual Basic for MS Excel Input operation conditions Normalize the data Estimate risks Denormalize data

Contact InfoContact Info

ARAJim Hall, 601-629-6165jhall@ara.com

Manuel Ayres410-540-9949 mayres@ara.com

ACRP StaffMichael R. Salamone (202) 334-1268msalamone@nas.edu

Questions?