LW aircraft speed specifications

[CWMV]

Originally Posted by JG52Uther

You two are one step away from a vacation, so cut it out.

With all due respect, put up or shut up! Lol!

Please, these two just can't controll themselvs.

[Crumpp]

Originally Posted by Crumpp

Nothing??

Really, think about it, every pilot has to account for it in their flight planning.

We will come back to it and here is a huge hint, if you recognize it.

Tell me, what is the difference between these too formula's?

Both formulat's express the same thing.





I am begining to think the men in the VVS were not so stupid, huh!

You certainly cannot explain it and you are pilot, right?

Both forumula's express Vw = V wahr = True Airspeed

This one represents the mathematical expression for True Airspeed recognized and used by the majority of the wartime world:



This one represents the mathematical expression for True Airspeed including
adaptation of the Prandtl–Glauert compressibility correction:



Such was the basis for the post war work on compressibility and compressible aerodynamics.

Since during the war, NII VVS did not have access to classified German research into compressible aerodynamics, their ability to correct Indicated Airspeed to True Airspeed to arrive at the same results as the Germans was limited.

[bongodriver]

Here we go, graphs and equations and name dropping German scientists.....all this fuss for what is simply compressibility error.

interestingly enough compressibility error makes an ASI 'over read' so not sure why compressibility error will have been a factor in the Russians tests not being able to reach speeds.

to this day the simple rule of thumb of 2% indicated airspeed per 1000' of altitude added gives a pretty accurate TAS result.

[Crumpp]

all this fuss for what is simply compressibility error

Surprised myself it took this long for a pilot to recognize it.

interestingly enough compressibility error makes an ASI 'over read' so not sure why compressibility error will have been a factor in the Russians tests not being able to reach speeds.

whooosh....

[bongodriver]

Originally Posted by Crumpp

Surprised myself it took this long for a pilot to recognize it.





whooosh....

Well if you just mentioned compressibility error in the first place it would have been simpler, but as usual you hide it behind the 'look at me and my clever internet aerodynamicist equations', another indication of someone who isn't a pilot, internet amateurs use gaphs and equations and pilots like to keep it simple with 'rules of thumb'
either way, now you have confirmed it you have also invalidated everything you contributed by failing to realise the error has the opposite effect to what the Russians were facing, apparently they couldn't reach the high speeds claimed despite their instruments over reading due to the error....

and to cap it all you put a smug 'whooosh' at the end

[Crumpp]

If the russian's calibrate their instruments based on the common expression for compressibility used at the time, they will always measure results which are slower than the German's.

Now, I don't know if that is the answer in this specific case. No details are passed along in the anecdote.

Robteks first post in this thread was spot on.

Robtek says:

This is so unspecified that it is absolutely worthless besides the anecdotical value.

What german fighters in which version and what equipment? No Information.

Were they trying to reach the 190 A8 speeds with a F8 or so?

And then hearsay from a german specialist, who might say anything to please his new masters.

Worthless for any real value deductions, i'd say.

I just took the opportunity to demonstrate the following to the community.

It is a fact, the expression for compressibility effects was NOT the same. The implication of that is you cannot take performance data from different countries during WWII at face value.

The other damning fact is that all instruments, manifold pressure, rpm, airspeed indicators, altimeter, etc...require both periodic maintenance and calibration.

You claim to be a pilot but do not seem to understand these basic facts.

Instead you leap on the anecdotal bandwagon because it is something you think will advance your game shape agenda.

It is no different than the ridiculous "testing" of performance without first understanding the atmospheric conditions.

Both incident's are example of behavior that folks who understand aircraft performance would not undertake!! Like I did, they would think it is a very silly thing to do.

My suggestion is less whining from the community about specific aircraft performance to fit an agenda and more enjoyment of the game.

[Crumpp]

now you have confirmed it you have also invalidated everything you contributed by failing to realise the error has the opposite effect

If the russian's calibrate their instruments based on the common expression for compressibility used at the time, they will always measure results which are slower than the German's.

[bongodriver]

You claim to be a pilot but do not seem to understand these basic facts.

No claims, it's all been proven.

Robteks first post in this thread was spot on.

Actually I can agree, but I only decided to question the sudden conviction to the theory it was all about the difference between IAS and TAS, really it doesn't matter who calibrates how, like I mentioned a simple 'rule of thumb' calculation gives a pretty accurate result, I'm sure the Russians had thumbs too (even opposeable ones) the compressibility effects you talked about were really geared around transonic flight, given the anecdote was in all probability talking about more mainstream German aircraft i.e. the piston engined ones then theres not too much chance the data you provided was applicable.

The other damning fact is that all instruments, manifold pressure, rpm, airspeed indicators, altimeter, etc...require both periodic maintenance and calibration.

Damming? how so? what makes you think the Russians were incapable of giving captured machines any maintenance, actually as a pilot i can tell you that instruments barely ever 'need' maintenance, sure they get checked for obvious reasons but seldom do they loose calibration.

I just took the opportunity to demonstrate the following to the community.

you demonstrated something? appart from the usual internet trawled stuff and equations which I have to admit were barely readable I saw no demonstrations of anything relevant.

Instead you leap on the anecdotal bandwagon because it is something you think will advance your game shape agenda.

My 'gameshape agenda' as you put it is towards accuracy.

It is no different than the ridiculous "testing" of performance without first understanding the atmospheric conditions.

Which I did....youre welcome by the way.

Both incident's are example of behavior that folks who understand aircraft performance would not undertake!! Like I did, they would think it is a very silly thing to do.

Yeah, your specialty, sitting on the sidelines thinking evryone else is stupid.

My suggestion is less whining from the community about specific aircraft performance to fit an agenda and more enjoyment of the game.

From a guy who whinges about aircraft performance and barely plays the game....

[fruitbat]

just stick Crummp on ignore, he's not worth it.

If he told me it was raining outside, i'd still have to look outside to check.

[bongodriver]

Originally Posted by Crumpp

If the russian's calibrate their instruments based on the common expression for compressibility used at the time, they will always measure results which are slower than the German's.

Doesn't matter how the Russians calibrate their compressibility, I'm sure the 'captured' 'German' aircraft they were testing had 'German' instruments in them anyway.