Originally Posted by BOAC
......and you are saying they are NOT part of the IRS/INS system, but separate accelerometers for assessing landings?
Yes
they are inputs to the FDRS and can be accesses through the ACMS. We would also pull the QAR disk/tape and get those read as well.
346 AMM - ACMS function: The DMU part receives the necessary data from the aircraft systems and monitors these continuously. Occurs a specified condition or event the FDIMU automatically starts a pre-programmed Report. The FDIMU stores the result of this report on the internal non-volatile solid-state mass memory (SSMM). The report with their result can also be recorded either on the internal Smart ACMS Recorder SAR or on the PCMCIA card (if installed) or on the external Digital ACMS Recorder DAR (if installed). The SAR storage medium is a part of the SSMM. The user can make a printout of the on the SSMM stored Reports. In addition the Reports can also be transmitted to the ground station through the ATSU (ACARS) or downloaded through the MDDU or PCMCIA card.
The system software consists following standard Reports:
For Aircraft Performing Monitoring:
- <02> Aircraft Cruise Performance Report
- <50> Cruise Stability Statistic Report
For Engine Trend Monitoring:
- <04> Engine Take-Off Report
- <01> Engine Cruise Report
- <09> Engine Divergence Report
- <08> Engine Reverse Report
For Engine Exceeding Monitoring:
- <10> Engine Start Report
- <06> Engine Gas Path Advisory Report
- <07> Engine Mechanical Advisory Report
For Trouble Shooting:
- <11> Engine Run-Up Report
- <05> Engine On Request Report
For APU Monitoring
- <13> APU Main Engine Start / APU Idle Report
- <14> APU Shut Down Report
For Miscellaneous Monitoring Functions:
- <15> Hard Landing / Structural Load Report
- <19> Environmental Condition System Report
- <20> Ram Air Turbine Test Report
- <21> Door and Escape-Slides Control System Report
- <16> User Programmable Report
- <17> User Programmable Report
- <18> User Programmable Report
AMM 31-33-00 -
The three-axis Linear Accelerometer (LA) is installed between Frame 46 and 47 under a floor panel of the passenger compartment (center of gravity of the A/C). The LA generates acceleration data in analog format. The analog information from the LA is sent to the System Data Acquisition Computer (SDAC). The SDAC converts this information to a digital format and sends it via an ARINC-429 data-bus to the FDIU-part. The FDIU-parts sends these acceleration data to the DFDR together with the other flight-parameters. On each flight the FDIU-parts makes an integrity check of the acceleration-parameters.