Transcript CVR / FDR Current Status of Investigation

A database of technical
and aerodynamic sounds
in aviation
Päivikki Eskelinen-Rönkä
Department of Speech Sciences
University of Helsinki
Aviation Intro
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Industry of strict regulations: Personnel,
technology, procedures
Organizations: ICAO, Eurocontrol, FAA, CAA
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Documentation: technology, procedures,
ratings (pilots + cabin crew) etc.
Accident investigation principles in Annex 13
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To find the cause, not the guilty!
Recorders
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Commercial aircrafts are equipped with Flight
Data Recorder (FDR) and Cockpit Voice
Recorder (CVR)
BLACK BOXES
Separate or combined recorders are usually
installed in the tail section
QAR, not crash survivable
Two storage mediums:
Analog: magnetic tape (30 min continuous)
 Digital: memory chips (2 hrs/CVR – 25 hrs/FDR)
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FDR
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FDR collects information from different
parameters, e.g. time, headings, altitudes,
speeds, and movements of flight controls
Number of parameters: from 18 to over 1000
Reconstruction of the flight: video animation
CVR
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CVR records all speech and audio information
in the cockpit and speech transmission systems
Several channels
CAM = Cockpit Area Microphone, AREA
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All technical and aerodynamic sounds
Speech transmission, Channels 1-3
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ATC transmission + passenger briefing + “hot
mike”
Accident investigation
To determine the probable cause of the accident:
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The recorders are located and removed
 Emergency Locator Transmitter, ELT
 Underwater Locator Beacon, ULB (37.5 KHz 14,000 ft)
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Analysis of recovered and translated FDR and CVR
data:
 Animations, transcriptions (spectral analysis)
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Separate investigations, tests etc.
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Collecting of reference samples
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Hearings, witness statements etc.
Problems with CVR and FDR analysis
CVR
 Unintelligible speech: changing noise levels and/or
G-forces
 Missing speech: unconsciousness, lack of CRM
FDR
 Slower sampling rate (e.g. 1-8 samples per sec)
 Longer recording time (e.g. 25 - 33 hours of data)
 Synchronization with CVR (absolute timing?)
 No separation between PIC and COP
 Malfunction
Without CVR -speech the analysis of
FDR data can be problematic
The cause of accident may be present in the
technical and aerodynamic sounds
Analysis tradition
Auditive analysis
 Experienced experts
pilots, preferably with same ratings
 ATCOs
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Qualitative analysis
Problems
 Highly sensitive material
 Reference samples?
 Objective investigation??
Database project
Arranging a separate test flight is a very
expensive way to collect reference samples
Database
Organized collection of sound samples from
different a/c types and models, e.g. Airbus A320 –
family, Embraer 170 etc.
 same type, but different a/c, e.g. Airbus A320
aircrafts 1-5
 from different procedures, e.g. taxing, take-off, enroute, approach etc.
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Future work
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Negotiations with
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Co-operation with AIB
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different Airline companies (Finnair at the moment)
pilots’ association
pilots’ trade union etc.
Database can be used in accident investigation
New quantitative analysis method
Funded by Etelä-Savo Regional Fund of the Finnish
Cultural Foundation.