11.18 On Board Maintenance System Flashcards
What is the purpose of OBMS?
To monitor and test the aircraft systems, to record and store the fault data, and to provide information about these faults to the flight crew and the engineer.
What is CMS?
Central maintenance systems
What is the primary purpose of the CMS?
monitor the fault status of aircraft systems, initiate aircraft system tests, generate fault reports from previous flight legs
What does a CMS consist of?
1 or 2 CMC’s
2 or 3 MCDU
What is the CMC?
Central maintenance computer, brains of the CMS
How many faults can be stored in the Non-Volatile memory?
500 faults
What classifications of faults does the CMS use?
Level A (Warning)
Level B (Cautions)
Level C (Advisory)
What is a hard failure?
Performance change of the system caused by a failure
What is a soft failure?
Failure that causes no immediate performance changes.
What is a maintenance memo?
lowest levels of indicated failure.
How are individual BITE systems connected to the CMC?
A digital bus either ARINC 429 or 629
What is an interruptive or manual BITE?
One where it must be started by crew.
What does MCDU stand for?
Multifunction Control Display Units
On the MCDU menu, what is found on page 1?
Support line maintenance and turn arounds. Page 2 is extended maint and troubleshooting
What is ACARS?
Aircraft Communications Addressing and Reporting System
What does ACARS do?
Sends faults reports back to operator.
What two modes does a disc drive unit operate in?
Automatic mode
Manual Mode
What can be done in automatic mode of a disc drive?
Both view and download
What format is the disc in a MDDU?
MS-Dos
What four sub-functions does the CMC have?
Data loading
Aircraft config monitoring
Repository management
Software pin
What is software pin programming?
Shows and makes the modification of aircraft computers configuration
What does the DLCS application do?
Stores and retrieves software to/from the repository.
What is a HMI?
principally an Airbus term where other manufacturers simply refer to the interface device in hand.
What two types of pin programming are there?
Hard
Soft
What is the ELS?
Electronic Library System
What is a class 1 EFB?
such as laptops or handheld electronic devices, such as iPads.
What is a class 2 EFB?
Class 2 are like Class 1 EFBs, but they are mounted on the aircraft and have electronic links to aircraft systems.
What is a class 3 EFB?
“installed equipment” and subject to airworthiness requirements
What is type A software?
static applications, such as document viewers
What is type B software?
electronic approach charts that are static or those that require panning, zooming, or scrolling.
What is type c software?
Multifunction Display (MFD); it has also been used to form part of an Automatic Dependent Surveillance-Broadcast system.
What are type c applications subject too?
Airworthiness directives
How are the inputs to the printer prioritised?
ACARS highest
ACMS
CMCS lowest
What can SHM facilitate?
40% reduction in maintenance cost
What are fatigue meters used for?
Used to record overall, accumulated stress levels on aircraft.
What are strain gauges used for?
to monitor stress levels on specific aircraft structures.
What are intelligent skins?
constructed with fibre optic sensors embedded in the material which are connected to signal processing units.
