11.18 OBMS

Question 1

What does the CMCS consist of?

Answer 1

• 1 or 2 CMCs
• 2 or 3 MCDU’s
• Datalink to acars
• Computer in each aircraft system

Question 2

What are the 2 modes of operation for CMCS?

Answer 2

Reporting and Interactive

Question 3

When can interactive mode be used?

Answer 3

AC on ground

Question 4

What are the two functions of bite?

Answer 4

• Detect failures

- Perform tests on ground

Question 5

When is bite carried out automatically?

Answer 5

Power on

Question 6

How is CMCs redundancy achieved?

Answer 6

Second standby CMC

Question 7

How is the standby CMC switched in?

Answer 7

Automatically in case of failure

- manually on some aircraft

Question 8

How is redundancy fulfilled in interactive mode?

Answer 8

backup channel

Question 9

What is MCDU used mainly for in flight?

Answer 9

Controlling FMS

Question 10

What does the “fail” annunciators on the MCDU indicate?

Answer 10

MCDU is defective, use another one

Question 11

How many lines and characters make up the MCDU display screen?

Answer 11

14 lines, each containing 24 characters

Question 12

What is the top line of the MCDU called?

Answer 12

Title line

Question 13

What is the bottom line of the MCDU called?

Answer 13

Scratchpad or message line

Question 14

When using MCDU, when might the “no response” message be shown?

Answer 14

If there is a printer failure, out of paper, or in use by another system

Question 15

How is the “no response” indication, indicated on airbus?

Answer 15

by an asterisk

Question 16

How could you confirm that a recorded fault is the cause of a “cockpit effect”?

Answer 16

Correlation of time, date and ATA chapter

Question 17

When does memorisation of faults begin?

Answer 17

Beginning of flight, 3 mins after engine start

Question 18

When does the memorisation of faults end?

Answer 18

Flight is terminated during taxiing

Question 19

How is an intermittent failure defined?

Answer 19

Occurs once or several times during flight but isn’t reported after landing

Question 20

What happens to the last flight data at the beginning of the next flight?

Answer 20

Moved into history memory

Question 21

How many previous flights is the fault history data retained for?

Answer 21

63

Question 22

On the ground when is reporting mode terminated?

Answer 22

When interactive mode is selected

Question 23

What are 2 main purposes of different test functions on CMC?

Answer 23

• Confirm most likely reported LRU is faulty

- Confirm component repair or removal solved problem

Question 24

What three tests can be carried out?

Answer 24

• System

- complementary and output

Question 25

Why arent tests allowed during flight?

Answer 25

In case flight safety is influenced

Question 26

How can tests be enabled manually?

Answer 26

ground test enable switch

Question 27

What happens to the system with the ground test enable switch in the normal position?

Answer 27

all test signals are interrupted

Question 28

What special precautions are needed for a system test?

Answer 28

None, it is only a computer test of the system

Question 29

Which test requires preconditions?

Answer 29

complementary test

Question 30

What is displayed when you carry out a complementary test?

Answer 30

- Caution message | - moving surfaces

Question 31

Why is the final selection of the complementary test a different line select key than the previous page?

Answer 31

To ensure the operator is fully aware of what is going to happen

Question 32

What is necessary at the end of the complementary test?

Answer 32

A close up, to bring AC back to original condition

Question 33

What is the main purpose of the output test?

Answer 33

To trigger a cockpit function for the operator to monitor

Question 34

How is a successful output test indicated?

Answer 34

It isn't, it is determined by the operator dependent on the indicator response

Question 35

How often must the FMS nav database update be updated?

Answer 35

28 days

Question 36

How can data loading be carried out?

Answer 36

- Airborne data loader - Portable data loader - Cross loading between computers

Question 37

When does the FMC data loading page appear automatically?

Answer 37

When 2 FMC's detect different part numbers at power on