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-   -   Va (https://www.pprune.org/flying-instructors-examiners/403821-va.html)

BA123 29th Jan 2010 13:21

Va
 
Can anybody answer the question does the speed Va increase or decrease with an increase in weight. And WHY ???

Cheers

what next 29th Jan 2010 13:32

Here is a good and brief explanation: Maneuvering speed - Wikipedia, the free encyclopedia

hugh flung_dung 29th Jan 2010 16:38

Va decreases with mass; the wikipedia link explains it well.

Va1=VA2*SQRTweight1/SQRTweight2 (from the lift formula)

HFD

DA-10mm 30th Jan 2010 03:45

are you kidding me?
is your instructor clueless?
are you clueless?
are you a pre-first-solo-student-pilot?
if not, change/fire your instructor...it would be the best move, career-wise, you ever make.

what next 30th Jan 2010 10:18

Hello!


DA-10mm: are you kidding me?
is your instructor clueless?
are you clueless?
are you a pre-first-solo-student-pilot?
if not, change/fire your instructor...it would be the best move, career-wise, you ever make.
Er, do you know what kind of course "BA123" is taking? I don't. But for all I know, he could be in the middle of a distance learning corse for the ATPL theory (beacuse this Va-stuff is not part of a typical PPL course.).

I did my ATPL that way. You have no "your instructor" to blame or to fire while you study at home during this kind of course. But you have to answer questions from time to time and send the results back to the training organisation (novadays via email, in my days we had to send letters by mail which slowed the process considerably) to progress to the next step. And sometimes, these home-study courses have not been written by didactic geniusses, to put it mildly. So who is he going to ask, if something is unclear? There are no instructors and no classmates. You see, what a blessing such an internet forum can be!

Greetings, Max

NB: I only meet "my" students once they have passed their theoretical exam and start with their practical instrument und ME flying. Changing or firing me would not really help in getting this Va question answered, would it?

Keith.Williams. 30th Jan 2010 16:47

VA (the Design Manoeuvre Speed) is the stalling speed at the Limiting Load Factor.

The Limiting Load Factor is fixed by the aircraft designers.

The stall speed at any given load factor is proportional to the square root of the Weight.

So if you know the VA for one weight, you can work out the VA for any new weight using the equation.

Va at new weight = VA at old weight x Square root of (New weight / Old weight).

(As said in a slightly different form in a previous post).


On first meeting this idea, some people ask "If the aircraft can survive say 3.5g at this high weight, why can it not survive a higher g at some lower weight?"

The answer is that although the wings might not break off, some of the other components would start to do so. The weight of the aircraft may have decreased, but the weights of indivual items like generators will not have changed. So imposing a greater g will overload their mountings.

markymojo 22nd Feb 2010 11:13

Hi Keith,

Heard you left Cabair - what are you up to these days?

Mark

DA-10mm 7th Mar 2010 04:35

Of course I don't know what course BA123 is taking. But I do know that "err" has two of the 18th letters of the English alphabet involved.
Level 3 or 4 English is not your friend, sorry.
How do you know it's a "he"? Are you sexist? Not all pilots are men.
Then again, "corse" is spelled with a "u" involved.
If you did your ATP that way, God forbid you're sitting on my right.
There's theory, and then there's practical application of knowledge.
what is "novaday...geniusses"?
In the end, BA123, it's a pretty easy theory to grasp, in order that you're ready absorbe and attain the wonders that are involved in all that is avaition, and not relying on others to give you information. You will gain the most knowledge by self-investigation (aka "figuring it out yourself").
been an instructor for over 15 years...have a question, PM me>

212man 8th Mar 2010 03:04


you're ready absorbe and attain the wonders that are involved in all that is avaition
You might want to check your own spelling and grammar, before jumping down other people's throats (especially if it appears that English may not be their first language - lives near Stuttgart!)

Intercepted 8th Mar 2010 12:56


been an instructor for over 15 years...have a question, PM me
You would be the last instructor I would contact for any type of service :rolleyes:

Curare 15th Mar 2010 01:57

Never a dull day on here


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