Originally Posted by ask26
Hi there, I am studying for my ATPL's and in looking at feedback I have 4 that I was wondering if people could help with, I think they are quite hard and so this is a more appropriate place than in the Wannabees forum:
1) An aircraft with a high Design Limit Load Factor allows a manufacturer to design for a smaller stick force/g
=== True or False
I think true as for example in an aerobatic aircraft you don't want to over stress the pilot so the sf/g would be less but the max stick force would be the same
True, the airworthiness standards for civil aeroplanes requires a minimum back stickforce of 15lbf to reach the maximum positive g limit. If the g-limit is higher, then Fs/g can be smaller for the same outcome.
2) The stick force/g is a limit in use of an aircraft; the pilot can check this out in the flight manual.
=== True or False
Untrue, it's a design factor - important in certification work, but largely transparent to operators.
3) Where is the discontinuity plane in a normal shockwave?
=== Normal to the surface
=== Normal to the relative airflow
Different websites suggest both but I was wondering if there is a subtle difference between one normal to the surface as a shock wave and normal to the relative airflow as in a bow wave.
Hmmm, a terminology question. I hate them - in my case I'm afraid that I'm not familiar with this particular form of words.
4) Does a bow wave form at M=1.0 or just above Mach 1
Again different results, Googling gave me Selkirk Aviation College that suggests at M=1.0 but Nasa seems to imply at above M=1.0
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Any help that people can give would be much appreciated
Generally a bit below in reality because of local flow variations, but for the purposes of a simplistic question it would form at M=1+a_little_bit, because that's the point when air ceases to be able to get properly out of the way. At M=1 the air is *only just* getting out of the way of the aeroplane without a shockwave forming.
G