Flight Data Recording & Data Transfer

Transcription

1 Flight Data Recording & Data Transfer

2 Flight Data Recorders

3 Dr David Warren Aeronautical Research Laboratory (ARL)

4 History Early recorders used scratch foil analogue recording Limited number of parameters Single use foil Digital recorders introduced in 1950s Tape based, so can overwrite after 25 hours Higher precision Better protection of data Defined in ARINC standard 573 Solid state recorders introduced in 1990s More robust than tape Lighter as no tape transport required

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6 Parameters or parameters? Hercules 7 parameters B737 NG 88 parameter rule 1063 parameters recorded

7 1100 ºC flame for 30 minutes. 260 ºC for 10 hours Immersion in aircraft fluids for 24 hours Immersion in sea water for 30 days 5,000 pounds crush for 5 minutes on each axis Pressure equivalent to depth of 20,000 ft. 3,400 G shock for 6.5 ms 500 lb. Dropped from 10 ft with a ¼- inch-diameter contact point

8 Quick Access Recorder Data Acquisition Unit Flight Data Recorder

9 Investigating aircraft accidents What does the Flight Data Recorder not need to record?

10 Things we don t need to record created during the training course Fuel Aircraft registration and Type Passenger list Departure and Destination airports = Route Date & time Weight

11 Flight data recorders - Summary Designed for accident investigation Parameters recorded depend upon age of aircraft manufacturer s design

12 Data Frames

13 Data Format Example of FDR data, with the frame start identified. 002AF5C C 0C F2 0E 3C 0C..v...d...<.ò.<. 002AF5D C 00 0C C..X...H AF5E0 00 0C E0 0F C 40 0C AF5F AF B 0E DF 0F 02 0C A5 0F G.w...+.ß....x. 002AF D3 01 D8 0F EA 03 A4 0F EE 0F FD 0F U.Ó.Ø.ê..î.ý AF E AF630 F8 0F C 0B 0C 00 0A ø...œ AF F C 0C F2 0E w..d...<.ò AF AC 00 4C L AF D0 02 0D B Ð...D AF670 A AF B 0E DF 0F 04 0C A5 0F w...+.ß AF D4 01 DA 0F EA 03 A4 0F 73 0E T.Ô.Ú.ê..s AF6A D AF6B0 FB 0F û AF6C C 0C F2 0E 3C 0C..v...d...<.ò.<. 002AF6D0 6A j.!...h AF6E AF6F FC 0F...ü. 002AF700 CC B 0E DF 0F 02 0C A5 0F Ì.w...+.ß....y. 002AF D4 01 D8 0F EA 03 A7 0F EE 0F FE 0F T.Ô.Ø.ê..î.þ...

14 ARINC 573 data frames The data is encoded in frames. The data in a frame consists of a snapshot of the many avionics subsystems on the aircraft. Each frame contains the same data at a different snapshot in time. Each frame is broken into four sub-frames. At the start of each sub-frame is a unique sync word that is used by the receiver to synchronize with the incoming data. Data rate minimum is 64 words per second. 128 & 256 wps common to allow more data to be recorded

15 Data frame layout Word T seconds T+1 sec T+2 sec T+3 sec 1 Sync Sync Sync Sync 2 Time Time Time Time 3 Heading Heading Heading Heading 4 Roll Roll Roll Roll 5 Engine 1 N1 Engine 2 N1 Engine 3 N1 Engine 4 N1 6 OAT Lavatory smoke to OAT Flap selection 64 latitude longitude latitude longitude

16 Sample rate = 1Hz Word T seconds T+1 sec T+2 sec T+3 sec X X X X to 64

17 Sample rate = 0.5Hz Word T seconds T+1 sec T+2 sec T+3 sec X X X X 4 Y Y 5 6 to 64

18 Sample rate = 2Hz Word T seconds T+1 sec T+2 sec T+3 sec 1 2 Z Z Z Z 3 X X X X 4 Y Y to 34 Z Z Z Z to 64

19 Data frame problems There is no rule about which parameter to record where There is no standardisation of data storage format Manufacturers purchase equipment from different suppliers New FDAUs are programmable The consequence is that a given aircraft type can have many alternative formats of FDR data Known as Data frame layout or Logical frame layout

20 Logical frame layout and signal conversion

21 Types of Flight Data Recorders FDR Originally data was supplied to a Flight Data Recorder. Hard to access as it was encased in steel and repeated downloading wears out the tape Can repeatedly download solid state FDRs QAR Quick Access Recorders stored the same data but on tapes or data cards that are easy to take off the aircraft DAR Direct Access Recorder stored data from programmable data frame, allowing large airlines to configure their own data frame Makes the frame layout problem worse!!!

22 Data Transfer

23 L3 Communications microqar By far the most common recorder at FDS Removable media Built-in clock Data transferred by compact flash card CF card MUST NOT be formatted microqar stores it s own serial number, date and time into the data stream

24 Avionica miniqar Older than uqar (did L3 Communications copy Avionica?) No clock No removable media Downloaded using Avionica s Ruggedised Service Unit (RSU)

25 Teledyne PC Card Teledyne DFDAU with PCMCIA data card slot Data files stored in DOS file structure

26 SAGEM PC Card SAGEM Flight Data Interface and Management Unit (FDIMU) has a slot for a PCMCIA data card Found on Airbus aircraft Data stored in files

27 Penny & Giles MO Disk Magneto Optical disk Like a small CD in a floppy disk cover Prone to data errors, especially upon landing due to vibration FDS recommend replacement by uqars.

28 L3 FA2100 Fairchild made the FA2100 FDR Fairchild were bought out by L3 Communications This solid state FDR uses data compression Can record more than the mandated 25 hours. (50-80 hours possible). Download using the Portable Interface unit (PI) Can select only data that has not been downloaded before, to avoid repeated transfer and analysis of old data

29 Honeywell FDAMS Installed on RJ100 aircraft and others Data stored in files, one file per flight Engineering data (engine running times etc) also stored in files on same card

30 Wireless downloading Where data is transferred wirelessly, we receive the data through an FTP site, however the underlying data format still complies with one of the data formats previously described.

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