747.400 Vmca?
Thread Starter
Joined: Oct 2003
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From: pastis land
747.400 Vmca?
As I do not know anythings about 747.400 is there any nice boeing pilot to answer thse terrible questions for me?What is higher Vmcg or Vmca on B 747/400? ( I never imagined it could be something else than vmcg<vmca, but...)
Is there any interrest to teach young student Vmca on airplane rather than simulator?
Thanks to those who could alight my brain!
Joined: Jun 2001
Aviation Qualifications: ATPL
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From: FNQ ... It's Permanent!
747-400:
VMCG
118 - 124 kts
VMCA
112 - 117 kts 1 Engine Out
152 - 160 kts 2 Engines Out
Very simply, VMC calculations generally allow for a slight bank into the live engine. Obviously you cannot bank while still on the ground, you only have rudder, so the VmcG is slightly higher than Vmca1.
VMCG
118 - 124 kts
VMCA
112 - 117 kts 1 Engine Out
152 - 160 kts 2 Engines Out
Very simply, VMC calculations generally allow for a slight bank into the live engine. Obviously you cannot bank while still on the ground, you only have rudder, so the VmcG is slightly higher than Vmca1.
Joined: Sep 2002
Posts: 2,188
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From: La Belle Province
Vmca is always higher, in all airplanes
There is nothing which requires that Vmca be either smaller or larger than Vmcg. They are the result of different manoeuvres/tests, at rather different aerodynamic conditions. Therefore there is no way you can point at a single factor and draw the conclusion that one or other must be larger.
It doesn't even have to be consistent on a single airframe for two different flap configurations.
Joined: Apr 2004
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From: vancouver oldebloke
Milt,I 'm possably confused but to recover from VMCA is Immediate(once one runs out of rudder control)...
The only time the 2 seconds apply is in the ASDA DISTANCE evaluation...NOT in the recognition/reaction by V!....
Or am I totally at sea???
Cheers
The only time the 2 seconds apply is in the ASDA DISTANCE evaluation...NOT in the recognition/reaction by V!....
Or am I totally at sea???
Cheers
Joined: Oct 2003
Posts: 1,300
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From: Canberra Australia
oldebloke
The reason we TPs use a 2 second delay is to account for an 'average' reaction time to a rapidly deteriorating situation.
This is based on the 'slower reactors' in the system.
If you can beat the 2 seconds you are getting up there towards the above average.
Of course in determining a reasonable Vmcg things can get decidedly pear shaped!!
The reason we TPs use a 2 second delay is to account for an 'average' reaction time to a rapidly deteriorating situation.
This is based on the 'slower reactors' in the system.
If you can beat the 2 seconds you are getting up there towards the above average.
Of course in determining a reasonable Vmcg things can get decidedly pear shaped!!
