is Vmca mean stall speed?
Joined: May 2013
Posts: 1,126
Likes: 2
From: have I forgotten or am I lost?
some kind soul bent the ground adjustable trim tab on a Cessna 150 of all things.
a mate was PIC and we went out for a fly to a local restorer of Tiger Moths.
on the flight back my mate asked me to put my foot on the right rudder so that he could give his leg a rest.
at my questioning it eventuated that he had lost muscle control of his right leg and had quietly poked his left foot on the right rudder. when this eventually also gave out he had both feet on the right rudder and both his legs had lost muscle control.
my right leg lasted a few minutes then I had both legs on the right rudder and finally we flew the aircraft with both of us with both legs pressed on the right rudder.
all because the little ground adjustable trim tab on the rudder had been bent to about twice its angle.
so Vmca is one thing. the elephant here is the question of just how long you could actually push hard on the rudder. the need doesnt diminish but the ability of human muscles to push sure diminishes.
...I'll go back to sleep....
a mate was PIC and we went out for a fly to a local restorer of Tiger Moths.
on the flight back my mate asked me to put my foot on the right rudder so that he could give his leg a rest.
at my questioning it eventuated that he had lost muscle control of his right leg and had quietly poked his left foot on the right rudder. when this eventually also gave out he had both feet on the right rudder and both his legs had lost muscle control.
my right leg lasted a few minutes then I had both legs on the right rudder and finally we flew the aircraft with both of us with both legs pressed on the right rudder.
all because the little ground adjustable trim tab on the rudder had been bent to about twice its angle.
so Vmca is one thing. the elephant here is the question of just how long you could actually push hard on the rudder. the need doesnt diminish but the ability of human muscles to push sure diminishes.
...I'll go back to sleep....
Joined: Feb 2000
Posts: 1,550
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From: Alaska, PNG, etc.
Maybe I've misunderstood you.
Joined: Feb 2008
Posts: 1,342
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From: Wingham NSW Australia
Double asymmetric
A Squared, my omission. What I failed to include in my post was Vmca. i.e. we never practiced double asymmetric flight in the B707 in the aircraft or in the simulator in relation to demonstrating Vmca. Given that you fly the C130 (L382) I can understand that you would look at double asymmetric in the Simulator, not so sure that I would agree with practicing the configuration in the aircraft. I know we did not practice it in the C130 other than in the Simulator. I assume you do not practice it in the aircraft at low altitude or at a speed anywhere near Vmca2. I also trust that in your aircraft practice you do not shut down the engines but come back to, or slightly above, flight idle.
Joined: Feb 2000
Posts: 1,550
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From: Alaska, PNG, etc.
Old fella, thanks. Makes more sense when you include "demonstrate VMCA" You are correct, we do not shut down engines, rather use a throttle setting close to flight idle which simulates a feathered engine. No, we do not get anywhere near VMCA2, and the simulation ends at MDA. I have seen 2 engine VMCA, but that was in the sim on a scenario with losing a second engine on a 3 engine ferry takeoff.
Joined: Jun 2011
Posts: 297
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From: Devonshire
Glider Overshoots P.S.
It was more than 60 years ago, when I did my gliding, as related above, as accurately as I can recall. (See # 13. # 15 or #19 above.)
Time has moved on and the French National Gliding Centre at Montaigne Noire, near Revel seems to have gone too.
The lessons that I learned there, may have been of help when I was having to trade height for speed following one propeller auto coarsening on overshoot at weather minima. To have attempted to retain all height might have led to a stall. My speed got awfully slow.
Time has moved on and the French National Gliding Centre at Montaigne Noire, near Revel seems to have gone too.
The lessons that I learned there, may have been of help when I was having to trade height for speed following one propeller auto coarsening on overshoot at weather minima. To have attempted to retain all height might have led to a stall. My speed got awfully slow.
Last edited by Linktrained; 23rd December 2013 at 21:57.




