11.18 On Board Maintenance Systems Flashcards
On board maintenance systems have been designed to bring the systems maintenance reporting in to one central location called what
The CMCS Central Maintenance Computer System
What does the CMCS consist of
- One or 2 central maintenance computers located in the avionics compartment
- 2 or 3 MCDUs (multi-purpose control and display units) in the cockpit as the main interface between a/c and engineer
- A cockpit printer for hard copies of info
- An ACARS connection to datalink the information to home base
- A digital computer in each a/c system which is linked to CMC for troubleshooting
Roughly how many individual computers are connected to the CMC
Between 50-100
What are the 2 modes of operation of the CMCS
- Reporting mode
- Interactive mode
What is the purpose of the reporting mode in the CMCS
Reporting mode is active during normal flight
It scans all of the aircraft systems and logs any faults
Where are the logged faults from the CMCS displayed
The MCDU, it can then be printed for a hard copy or sent via ACARS datalink
What is the purpose of interactive mode of the CMCS
Interactive mode is only available on the ground and is used for functional checks and investigations
What does BITE stand for
Built In Test Equipment
What are the 2 BITE functions available
- To detect failures
- To perform system tests on the ground
What is the MCDU used for during flight
It is used to control the FMC (Flight Management Computer)
When would a No Response message appear on the CMCS
- Not working
- Out of paper
- In use by another system
