Aircraft Accident Investigation By Chinmay Patel Roll No

Aircraft Accident Investigation By: Chinmay Patel Roll No: 98001019

Outline n History of Flight Data Recording n Recording and Storage of Data n Flight Data Recorder (FDR) n Cockpit Voice Recorder (CVR) n Crash Survivability Features n Post Crash Procedures n Information Retrieval n Aircraft Reconstruction as a Technique

History n Wright Brother’s recording of propeller rotations n First Generation FDRs Ø Ø Stainless Steel Tape 200 to 400 hrs of information n 1958: 1 st mandate in USA n 1960: 1 ST mandate in UK First Generation FDR

History n 1970 s: Second Generation FDRs n n FDAUs introduced Magnetic Tapes used n 1991: Solid State Memory FDRs n 34 Parameters for 25 hrs Second Generation FDR

Recording and Storage n Magnetic Tapes n Track about 100 Parameters n 30 minutes of CVR audio n Solid State Memory Boards: Stacked array of memory chips No moving parts n More reliable n More Parameters (~ 700) n 25 hrs of FDR data + 2 hrs of CVR audio n

Data Acquisition n Location on the Aircraft

FDR n Sensors FDAU FDR n Minimum of 11 to 29 Parameters to be Recorded n Eg: Time, Pressure Altitude, Airspeed, Heading, Accelerations, Control Surface Settings, Fuel Flow, Engine RPM & Temperature… etc Solid State FDR

CVR n Records all kinds of Cockpit Conversation, Warning alerts & Noises n Various Microphones in the Cockpit record sounds Pre-amplified Digitized Stored n Re-write older material n Provide an idea of the Crew’s Situation & Decisions taken

Crash Survivability n Crash Survivable Memory Unit (CSMU) n Damage resistant features n n n Aluminum housing Dry Silica Layer for insulation Steel/Titanium shell n Thoroughly tested against impact, fire and environmental damage

Post Crash Procedures n Locating the Black Box n n Orange in color Underwater Locator Beacon n Pulses of 37. 5 k. Hz every second for 30 days Can transmit sound from 14000 ft under water Can be tracked by Ultrasound Sensors Black Boxes are transported with utmost care n Kept in environment identical to that in which it was found n ULB

Information Retrieval n Manufacturers supply NTSB with H/W & S/W for Data Retrieval n Team of experts interprets the data from FDR and the CDR audio n A typical team includes: Airline representative n Airplane Manufacturer representative n NTSB Transportation-Safety Specialist n NTSB Air-Safety Investigator n

Aircraft Reconstruction n 2 D as well as 3 D reconstruction n Decide n Origin & Cause of Failure n Chain of Events n Important investigation technique n Better understanding of Failure Modes n Helps in ruling out false theories n Assurance that no possibility is left out

Comet G-ALYP Reconstruction n De Havilland Comet (1954) n Mid-air Explosion: 35 lives lost n Reconstruction provided clue to failure modes n Culprit: Fatigue failure of the stressed skin

TWA 800 Reconstruction n Boeing 747 -131 (1996) n Mid-air Explosion n 230 lives lost n Several Controversies n Reconstruction helped to rule out false theories n Total of 876 pieces arranged n Culprit: Explosion in central fuel tank