Rich Freeman on 19 Jul 2017 18:30:40 -0700


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Re: [PLUG] Waaaaay Off Topic: Thunderstorm Movement


On Wed, Jul 19, 2017 at 5:48 PM, Lee H. Marzke <lee@marzke.net> wrote:
>
> What I also wanted to do on my Decathlon aerobatic flight was inverted flight,  and to steer towards a point
> on the ground inverted, as I couldn't figure out how that worked.  In normal flight, When you bank right , the
> nose goes right, however it turns out when inverted, and you bank right, the nose goes left ! That
> screwed up my mind until figued it out.
>

I've done it on flight sims - it is pretty intuitive there.  I'm sure
it is less intuitive when you're hanging by your shoulder straps.  In
sims at least you tend to need a fair bit of "negative" pitch to
maintain level flight, probably because the wings aren't shaped for it
(I assume that there is a lot more induced drag as well, but I'm not
sure about that).

> The recommended emergency descent through a cloud layer without a
> gyro is to enter a spin ( which IS stable in most gliders ), and hold the spin until you break
> out of the bottom of the cloud, and then recover from the spin.   OK,  not sure I really want
> to do that maneuver.  I'm OK with spins when I can see but not in a cloud.

That is really interesting.  I'm pretty sure spins are stable in most
aircraft - that is why they're so deadly.  With most other undesired
situations the aircraft will return to normal flight if you just let
go of the controls assuming they're properly trimmed.  With a spin
that doesn't happen because it is stable (that is, when perturbed
slightly away from the spin the plane will want to re-enter the spin -
it takes firm/deliberate control inputs to get it out).

Of course, every plane is different.  When I was doing power off
stalls in the 172 I could barely tell that it had entered the stall
(horn hadn't quite gone off) but it was clear from the VSI, and it
barely took any effort to recover with very little altitude loss.
From what I understand something like an airliner is a whole different
beast in a stall.

> The handle on the far left in cockpit during TO roll are the spoilers.

Yeah, I've played around in gliders a bit in the sims as well.  I'm
sure it isn't quite the same but they do have spoilers and negative
flap settings, and ballast.  I guess they leave the spoiler off until
they take off to reduce the load on the gear.  I was thinking that the
guy sitting on the wing might over-load it, especially at the end, but
then I realized that during flight the load is actually upwards and if
anything he's probably balancing it out somewhat as he moves outwards.

Thanks for the video links - they were interesting, and the sound of
the variometer brought back memories!  I was surprised by some of the
maneuvers and looked up the L-23 manual, and it looks like it will
handle load factors around 6 - I guess without any fuel/etc they can
build them fairly strong.

Makes me want to go flying again, well, until I remember the landing
approach over the trees at KUKT which seems to always be rough.  (It
is much more pleasant at airports that have plenty of grass, like
Trenton/ABE/RDG.  Landing there is like putting it on easy mode...)

-- 
Rich
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