December Perf/PoF

[Charlie Zulu]

Hi All,

Just got home from Gatwick and thought that I would start the monthly "ATPL Performance exam today" thread. :D

This month was mostly feedback. Two graph questions, one on SEP and the other being MEP (2 and 3 marks).

Can I check that everyone else got 3490' for one of them because the "heavy duty brakes" took 7% off the graph answer. Also the other one I came out with something like 1950' (er I think that was the answer I worked with - it has been a few hours and I've totally forgotten!).

Also in typical fashion, I've forgotten the actual graph question wording...

What did everyone else put as the answer to the "parabolic polar" question in PoF? I used Induced + Parasite Drag but I didn't like any of the possible answers.

Also "When can an aerofoil be considered cambered?" in PoF? I put "when the upper surface is cambered". It was the only option that sounded reasonable.

I really hope I don't have to go through these two exams again!

Thanks in advance.

Charlie Zulu.

[FFP]

Can confirm I got the same on the Perf and answered the same on the PoF. . . . .

So either we are both right . . .. :ok:

[Charlie Zulu]

Let us just hope we are! :D

[smith]

POf

Polar graph was the parasitic drag/induced drag curves.

Camber, was something to do with fitting circles or something, as a symmetrical wing's camber is 0.

I answered the same as you, but I now know I got the camber one wrong.

[smith]

Amother one from PoF

What is used as a stall warner in a jet a/c?

I put stick shaker but I think the answe was stick pusher.

[Kengineer-130]

stick shaker is correct for stall WARNER :ok: , it shakes the stick when the aircraft approaches a stalling AOA/airspeed. The stick pusher is applied when the pilot fails to take corrective action, ie regain a non-stalled AOA, and simply "pushes" the yoke forwards to regain AOA/ airspeed.

[smith]

Thanks kengi,

Quetion

What is used as a stall warning in a MRJT?

I think the answers were

a) aural warning
b)visual warning
c) stick shaker and/or buffet
d) stick pusher

Problem I have was there is no pre-stall buffet in a jet, technically I think all of them are correct in their own right.

[ClearReverse]

The answers to the perf exams you have given are 100% correct, the SEP is 1950ft and the MEP is 3490, for the MEP one you should have got approx 3750ft out of the graph and as stated decreased by 7% for the heavy duty brakes.

:ok:

[Tallbloke]

JAR-OPS says words to the effect that if the aircraft has no natural stall warning the pilot must be provided with one, i.e. if you can't feel the buffet a stick shaker is required.

As for the parabolic curve question, all I could get from it is that when Cl =0 Cd=parasite drag only, therefore it is possible to deduce parasite drag coefficient. That was my logic to selecting the only answer which appeared to fit.