Center of gravity on airplanes question.

[JB73]

i have never read any information about this, so i have to wonder...

in WWII there were planes with many different ammo loads on the same airframe. in ym example i am going to use the 190A5.

in game we have 2 loadouts, one with only 2 cannons, and one with 4 cannons. mentioned in another thread i have seen first hand the performance difference in the to loadouts, so i understand that ammo weight is modeled in game.

so here's my question. in real life with a different ammo load, and the obvious weight differences, how much did that effect the flight chareristics of a plane, and how did it move the center of gravity of the airframe?

mentioned in other threads, planes turn and roll on their center of gravity. if such an obvious change in the nose weight of a plane we present, wouldn't it throw off all filght manuevers?

did they add or remove ballast of some sort near the tail to equalize the plane?

what about the P47's with all those huge ammo differences. did the wingload change dramatically? did they do anything to counter this effect?


thanks, just thought of this odd scenario.

[Starbird]

The CG would be somewhere around 20-30% chord on most ww2 planes, as a guess. With guns and ammo in the wings I wouldn't think that would change the CG all that much.

Flight performance would be highly effected with the extra weight. You can see this with a fully loaded p-47 versus a light p-47 in ah. With all the ammo, fuel and bombs out on the wings, the roll intertia of the aircraft is increaed, so it wouldn't want to roll as fast as a light p-47.

An aircraft with wing tanks will roll faster with its tanks emptied than the same aircraft with tanks full. The stall speed also increases with a higher wing loading, along with all of the problems that encompases.

All of the wing mounted weapons (bombs, rockets, gondolas) would be designed so that their weight is as close to the CG as possible, so that releasing them wouldn't move the CG too much. Aircraft with nose mounted guns and fuel tanks would be designed with them in mind, and the weight could be offest with a longer tail moment.

So I would think that if the aircraft is engineered with these limits in mind, you as a pilot won't have to worry too much.

Thats how I understand it.

[JB73]

that si a valid point about the roll rate and stuff but lets look at another example.

the 109G10.

i don't know exactly where the CG is, but i doubt it is directly center of the wing roots. if that is that case, loading the gondolas on the plane even though on the wing, might be forward or behind the CG.

going further ot the extreme are bombs and rockets. they have even more weight.

now that effect on the CG of the plane, how strong is it, and again did they counter it in some way in the field?

all i can guess is they did something different with the different plane loadouts in the field, but have never seen a mention of it.

[hitech]

Dropable ordanance would be hung as to not change the CG.

Also to clairfy, roll rate does not change when adding stuff wings . But it does take longer to get the roll going and stop it.

HiTech

[JB73]

TY for the info. did not know either

so when you say roll rate not changed, you mean the actual distance travled over time of the wingtips correct?

in your explnation, where it might take a plane 5 seconds to roll 180, the wing tips travled at XX degrees/second rotation.

with a wingload, it might take 6 second to complete the same 180 roll, but at their top speed of rotation they would still travel at XX degrees/second instead of YY degrees/second.

am i getting that right?

[hitech]

Correct

[Starbird]

I knew I'd get something wrong in that post.