ATPL bristol questions/answers that do not seem right.

[hatallas]

hi
i a busy workig on my AGK with bristol (i am not a bristol student).
and i came accross this question, and dont agree with the answer, couldt any1 tell me why i am wrong...

If the maximum operating pressure of the oxygen system is exceeded the:

Passenger oxygen masks will drop down (the answer i gave)

Oxygen is discharged overboard via a safety plug. (bristol right answer)

[VFR Transit]

Now I am not doing the ATPL theory so could get this wrong myself, however my idea would be that Bristol is correct.

If the maximum operating pressure of the oxygen system is exceeded the:

Passenger oxygen masks will drop down (the answer i gave)

Oxygen is discharged overboard via a safety plug. (bristol right answer)

safety plug to me could mean a safety releif valve!! which in turn means should the system be set up as 2 bar max operating pressure and then the system starts running over at say 3 bar (being over the max operating pressure) the system will vent the excess (blowout) using the safety plug.

Like i said i am not doing the ATPL's, so await to be corrected.

VFR

[hollingworthp]

It's certainly correct for my aircraft type.

[Boeing 77W]

Bristol is correct

[hatallas]

when they say overboard, do they mean out of the aircraft, or out of the container?
english is not my first language, so most of the time i have difficulties interpreting the meaning of some questions...

[hatallas]

alright, sweet thanks :ok:

[Mercenary Pilot]

If the maximum operating pressure of the oxygen system is exceeded the:

Passenger oxygen masks will drop down (the answer i gave)

Wrong because on the vast majority of airliners, pax O2 is generated via chemical cylinders (above the seats) which are activated by pulling the masks down. The pax masks are usually lowered in 1 of 2 ways.

1/ Manually activated by the crew via an electrical switch

or

2/ Automatically activated when cabin pressure drops below a certain level (usually around 10'000 pressure alt)

Oxygen is discharged overboard via a safety plug. (bristol right answer)

This is the correct answer. Although it isn't really very clear (good 'ol JAR ATPL question bank:ugh:), it is talking about the crew oxygen which gets topped up by maintenance every so often. If they put to much in, there is a safety plug which blows and releases the O2 overboard. There is a way of inspecting this preflight on most types (usually a green disk).


MP
:ok: