 CFI oral intel
More_Flaps <Moreflaps@> wrote in
news:b1345c9e-2b51-4f40-a7f8-7724677a5446@i18g2000prn..com:
> On Jun 4, 9:38 pm, Michael Ash <m...@mikeash.com> wrote:
>> In rec.aviation.student Gezellig <geezel...@> wrote:
>>
>>
>>
>>
>>
>> > Michael Ash pretended :
>> >> In rec.aviation.student Gezellig <nokon...@> wrote:
>> >>> On Fri, 30 May 2008 01:20:04 -0500, Michael Ash wrote:
>>
>> >>>> Joking aside, if your straps were loose enough that you could
>> >>>> slump forward, that *would* affect your CG which would in turn
>> >>>> affect your trimmed airspeed.
>>
>> >>>> There's another issue that I just thought of that I don't think
>> >>>> anyon
> e has
>> >>>> mentioned yet, though. Won't you get into a graveyard (bad
>> >>>> terminolog
> y for
>> >>>> this scenario, as you're already dead) spiral? After all, if you
>> >>>> coul
> d
>> >>>> stay straight and level just by taking your hands off the
>> >>>> controls yo
> u
>> >>>> wouldn't need to fear IMC with no gyroscopic instruments. So it
>> >>>> seems
> that
>> >>>> if you start high enough, the correct answer to this question
>> >>>> would b
> e
>> >>>> whatever the terminal velocity of your fuselage is without its
>> >>>> wings.
> Am I
>> >>>> off base here?
>>
>> >>> You fly until gassless, stall, nose down, then descend too
>> >>> rapidly, striking the ground with the wings ripped off. Works for
>> >>> me.
>>
>> >> You don't stall, because when the engine quits the airplane will
>> >> start
> to
>> >> descend, maintaining approximately the original airspeed.
>>
>> > At what point do you expect to lose the wings via "the correct
>> > answer to this question would be whatever the terminal velocity of
>> > your fuselage is without its wings."?
>>
>> If you enter a spiral dive as I surmised, the wings fall off either
>> when you exceed Vne or when you exceed the maximum loading the wings
>> can support, whichever comes first. However it would seem that
>> whether this happens or not will depend on the airplane in question.
>>
>
> If the plane is in a steady dive at 2x VNE what is the wing loading?
> VNE may be set by srface instability (flutter) or perhaps engine
> overspeed but is not set by wing loading -that is Va -at least that's
> my understanding.
>
That's right, but the tendency to flutter is exacerbated by load. So, if
you're over redline and you're loading the wing, flutter will occur at a
lower speed than if that surface was unloaded. Flutter is all to do with
the elastic properties of the flight surface, so if it's loaded up
you're exciting the cycle.
Bertie
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