Does HTC calculate CoG or use NASM documents for the Ta152?

[Zimme83]

Ta 152:


And the Dora:

[Vraciu]

Not really, whats matter is the center of gravity of the fuel tank, and that is a POINT...

Not exactly.   Every fuel tank is different.   Fuel in the tank has an arm that varies based on what's in there and it isn't always linear.

[Vraciu]

The evidence indicates that the Ta-152 forward fuel tank is on the CG.

Maybe because the Cessna is a 1,600 lb airplane instead of 10,000 lbs and the 200 lb pilot already sits in front of the CG?

The evidence indicates that the Ta-152 forward fuel tank is on the CG.

Maybe because the Cessna is a 1,600 lb airplane instead of 10,000 lbs and the 200 lb pilot already sits in front of the CG?

All airplane's experience CG shifts based on occupant movement.   After the US Airways Express Beech 1900 crash the entire industry in the USA went through a major change in how Weight and Balance is calculated.   Our envelopes and how they're utilized changed as did standard weights for pax and bags. 

Long story short is we now accommodate passenger movement in ways we didn't before.   Our CG envelope for average weights got narrower as a result with few, if any, exceptions. 

If a 50,000+ lb airplane is be affected you can see that a single engine piston fighter will be as well. 

[Vraciu]

The TA had a rubber bladder inside the fuel tank which would prevent the fuel from moving around...

That's simply not the case.   It is going to move somewhat.   The only way to mitigate fuel movement is via baffles and such.   In large aircraft this is standard otherwise turning would be a rather interesting event.

[Vraciu]

The bladder would hold the fuel, a baffle would lessen it sloshing about.

And that "point" might change position depending on the shape of the tank.

This and this.

[Vraciu]

Test method is as follows:

Fuel burn times 10

Set power, turn of autopilot. Combat trim off as well.

Switch to desired tank. Burn until empty and see what happens. Not much happens in pitch burning any tank. Wing tanks do have an effect on roll.

Is it possible the autopilot is horsing the controls some and not using trim?

Can you trim it up manually and leave it hands off in pitch to see what it does?

[Zimme83]

That's simply not the case.   It is going to move somewhat.   The only way to mitigate fuel movement is via baffles and such.   In large aircraft this is standard otherwise turning would be a rather interesting event.

In a straight and level flight in the MA environment there will be no movements of the fuel so that would not affect the 'test'

[Vraciu]

In a straight and level flight in the MA environment there will be no movements of the fuel so that would not affect the 'test'

Impossible.   The fuel will move toward the lowest point in the tank.   Unless the tank is perfectly symmetrical (not possible with a bladder, and difficult at best with a wet cell) it will shift. 

[FLS]

All airplane's experience CG shifts based on occupant movement.   After the US Airways Express Beech 1900 crash the entire industry in the USA went through a major change in how Weight and Balance is calculated.   Our envelopes and how they're utilized changed as did standard weights for pax and bags. 

Long story short is we now accommodate passenger movement in ways we didn't before.   Our CG envelope for average weights got narrower as a result with few, if any, exceptions. 

If a 50,000+ lb airplane is be affected you can see that a single engine piston fighter will be as well.

I'm sure Hitech kept that in mind when he considered passenger movement on the Ta-152.   

The next complaint will concern incorrect trim change when the paratroopers jump out of the C-47.   

[AAIK]

Is that a 190 with an mk103 as an optional loadout?

[Zimme83]

3 of them...

[Krusty]

The question is not "does HTC dynamically compute weight shifting during flight" -- we know they do. The quest is: The base underlying model of the Ta-152... Was it based off the bad NASM testing reports? Or was it based off Luftwaffe factory documents? Does it take the proper tail balance into account or is it based on a root setup that is in error because it was testing based on a poor quality field repair?

[Zimme83]

Part of the problem is that the stall itself probably isnt modeled correct. For a good reason, simulating the air flow around the wings when the aircraft is stalling would prob require a lot of computing power...

[Dawger]

Is it possible the autopilot is horsing the controls some and not using trim?

Can you trim it up manually and leave it hands off in pitch to see what it does?

Test conducted with the AP off. AP on would be an invalid test.

[Vraciu]

Test conducted with the AP off. AP on would be an invalid test.

Well, there you go then.