A database of technical and aerodynamic sounds in aviation Päivikki Eskelinen-Rönkä Department of Speech Sciences University of Helsinki

Aviation Intro Industry of strict regulations: Personnel, technology, procedures Industry of strict regulations: Personnel, technology, procedures Organizations: ICAO, Eurocontrol, FAA, CAA … Organizations: ICAO, Eurocontrol, FAA, CAA … Documentation: technology, procedures, ratings (pilots + cabin crew) etc. Documentation: technology, procedures, ratings (pilots + cabin crew) etc. Accident investigation principles in Annex 13 Accident investigation principles in Annex 13 To find the cause, not the guilty! To find the cause, not the guilty!

Recorders Commercial aircrafts are equipped with Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) BLACK BOXES 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 Separate or combined recorders are usually installed in the tail section QAR, not crash survivable QAR, not crash survivable Two storage mediums: Two storage mediums: Analog: magnetic tape (30 min continuous) Analog: magnetic tape (30 min continuous) Digital: memory chips (2 hrs/CVR – 25 hrs/FDR) Digital: memory chips (2 hrs/CVR – 25 hrs/FDR)

FDR FDR collects information from different parameters, e.g. time, headings, altitudes, speeds, and movements of flight controls 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 Number of parameters: from 18 to over 1000 Reconstruction of the flight: video animation Reconstruction of the flight: video animation

CVR CVR records all speech and audio information in the cockpit and speech transmission systems CVR records all speech and audio information in the cockpit and speech transmission systems Several channels Several channels CAM = Cockpit Area Microphone, AREA CAM = Cockpit Area Microphone, AREA All technical and aerodynamic sounds All technical and aerodynamic sounds Speech transmission, Channels 1-3 Speech transmission, Channels 1-3 ATC transmission + passenger briefing + “hot mike” ATC transmission + passenger briefing + “hot mike”

Accident investigation To determine the probable cause of the accident: The recorders are located and removed The recorders are located and removed Emergency Locator Transmitter, ELT Emergency Locator Transmitter, ELT Underwater Locator Beacon, ULB ( 37.5 KHz 14,000 ft ) Underwater Locator Beacon, ULB ( 37.5 KHz 14,000 ft ) Analysis of recovered and translated FDR and CVR data: Analysis of recovered and translated FDR and CVR data: Animations, transcriptions (spectral analysis) Animations, transcriptions (spectral analysis) Separate investigations, tests etc. Collecting of reference samples Hearings, witness statements etc.

Problems with CVR and FDR analysis CVR Unintelligible speech: changing noise levels and/or G-forces Unintelligible speech: changing noise levels and/or G-forces Missing speech: unconsciousness, lack of CRM Missing speech: unconsciousness, lack of CRMFDR Slower sampling rate (e.g. 1-8 samples per sec) Slower sampling rate (e.g. 1-8 samples per sec) Longer recording time (e.g hours of data) Longer recording time (e.g hours of data) Synchronization with CVR (absolute timing?) Synchronization with CVR (absolute timing?) No separation between PIC and COP No separation between PIC and COP Malfunction 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 Experienced experts pilots, preferably with same ratings pilots, preferably with same ratings ATCOs ATCOs Qualitative analysis Qualitative analysisProblems Highly sensitive material Highly sensitive material Reference samples? Reference samples? Objective investigation?? Objective investigation??

Database project Arranging a separate test flight is a very expensive way to collect reference samples Database Database Organized collection of sound samples from different a/c types and models, e.g. Airbus A320 – family, Embraer 170 etc. 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 same type, but different a/c, e.g. Airbus A320 aircrafts 1-5 from different procedures, e.g. taxing, take-off, en- route, approach etc. from different procedures, e.g. taxing, take-off, en- route, approach etc.

Future work Negotiations with Negotiations with different Airline companies (Finnair at the moment) different Airline companies (Finnair at the moment) pilots’ association pilots’ association pilots’ trade union etc. pilots’ trade union etc. Co-operation with AIB Co-operation with AIB Database can be used in accident investigation Database can be used in accident investigation New quantitative analysis method New quantitative analysis method Funded Etelä-Savo Regional Fund of the Finnish Cultural Foundation. Funded by Etelä-Savo Regional Fund of the Finnish Cultural Foundation.