PDA

View Full Version : Performance Problem


Jinkster
15th May 2004, 14:30
Hello all,

Another quick performance question.

An aeroplane is in a power off glide at best gliding speed. If the pilot increases the pitch attitude the glide distance:

a) remains the same
b) may increase or decrease depending on the aeroplane
c) decreases <---answer
d) increases

Explanation please :ok: - I thought that the if the pilot increased the pitch, the glide distance would increase. :hmm:

Which of the following set of factors could lead to a V2 value which is limited by VMCA?

a) low take off mass, low flap setting and low field elevation
b) high take off mass, high flap setting, low field elevation
c) high take off mass, low flap setting, high field elevation
d) low take off mass, high flap setting and low field elevation <--answer

Explanation please :ok:

Thanks, I owe someone a pint :ok:

rodquiman
15th May 2004, 15:14
To the first question:

If you change your pitch you change your speed, so you are not at you best gliding speed which is the one that gives you the maximum range. You have to keep the maximum L/D and you get it with only one pitch attitude for each density altitude and each weight.

To the second question:

With the condition given in answer D you will have really low take off speeds (V1, Vr, V2) so they are closer to Vmca. Now add a low TOW and a low field elevation which help to increase Vmca and you will have Vmca close to V2 or Vmca higher than V2.

:ok: