could real life aircraft take it?

[Wingnutt]

I was wondering about some of the extreme "gamey" manuevers you see on here, for example people rapidly going from pulling a very high positive g to a very high negative G over and over again.

seems like even pretty robust aircraft would suffer rapid and severe structural fatigue from such abuse..  slamming a 109 from +6 g to -5 or within less than 1 second.. seems like alot of stress on the airframe.


thoughts?

[CAP1]

I was wondering about some of the extreme "gamey" manuevers you see on here, for example people rapidly going from pulling a very high positive g to a very high negative G over and over again.

seems like even pretty robust aircraft would suffer rapid and severe structural fatigue from such abuse..  slamming a 109 from +6 g to -5 or within less than 1 second.. seems like alot of stress on the airframe.


thoughts?

and on the pilot too

[Cthulhu]

I was wondering about some of the extreme "gamey" manuevers you see on here, for example people rapidly going from pulling a very high positive g to a very high negative G over and over again.

seems like even pretty robust aircraft would suffer rapid and severe structural fatigue from such abuse..  slamming a 109 from +6 g to -5 or within less than 1 second.. seems like alot of stress on the airframe.


thoughts?

We talking limit stresses or fatigue? They're two different animals. Besides, even low cycle fatigue occurs over thousands or even tens of thousands of cycles. Since you get a brand new plane everytime you up, no biggie.

Cap1 is right, it's the driver who's taking the real beating.

[Wingnutt]

I think that in ww2 if you took a real 109 up, pulled back on the stick till you hit 6gs then immediately slammed it all the way forward as hard as you could.. till you pulled g's far beyond red out, then pulled back again to max positive g.. over and over again..  I cant help but think that would damage the aircraft almost immediately.

[DiabloTX]

Are the stories of P-51's coming back with bent wings an urban myth or are they grounded in some sort of truth?

[AquaShrimp]

Truth.  High speed dives could permanently deform the wings.  The Mustang had a few problems with structural failures.  Due to a variety of reasons, it had a propensity to shed its wings or tail. 

I once read that the Mustang was only designed to be in combat for 16 weeks.  After that it would be considered war-weary.  Aluminum is light, but it isn't the best metal for handling repeated stress.  Once aluminum is overstressed, it will be weaker at the point where it was bent.  Steel doesn't have this sort of memory.

[Bronk]

Truth.  High speed dives could permanently deform the wings.  The Mustang had a few problems with structural failures.  Due to a variety of reasons, it had a propensity to shed its wings or tail. 

I once read that the Mustang was only designed to be in combat for 16 weeks.  After that it would be considered war-weary.  Aluminum is light, but it isn't the best metal for handling repeated stress.  Once aluminum is overstressed, it will be weaker at the point where it was bent.  Steel doesn't have this sort of memory.

Source?

[gripen]

I once read that the Mustang was only designed to be in combat for 16 weeks.  After that it would be considered war-weary.  Aluminum is light, but it isn't the best metal for handling repeated stress.  Once aluminum is overstressed, it will be weaker at the point where it was bent.  Steel doesn't have this sort of memory.

I won't be suprised if the American fighters were built for in average 100-200 hours. However, there were plenty of P-51Bs and Cs in service when the hostilities ended.

[Yossarian]

Source?

In Robert Johnson's book "Thunderbolt", he talks about how (his?) Thunderbolt had wrinkled wingtips after pulling out of a compression dive.

[colmbo]

If within limits the rapid stick pump to G limit wouldn't break the airplane -- the first time you did it. <G>  Everytime you pull G you stress the airframe.  With time the structure is weakened -- hence the War Weary status of aircraft.  Same reason the aerobatic pilots today "retire" their airplanes after a while -- they're worn out.


Aquashrimp - Minor point about the Mustang:  The high speed dive didn't damage the airplane the loads induced in recovery from the dive were the problem.  The wing loss problem on the Mustang came from something with the gear.  I don't remember the exact details, something about no uplocks on the gear, doors sagging.

[AquaShrimp]

Source?

"P-51 Mustang".  I don't have the book here in front of me.  However, it was about 350 pages of first hand accounts of Mustang pilots and ground crews.  Made in the 70s I believe.  Awesome book.

[Bronk]

"P-51 Mustang".  I don't have the book here in front of me.  However, it was about 350 pages of first hand accounts of Mustang pilots and ground crews.  Made in the 70s I believe.  Awesome book.

Thanks, see if I can pick it up.

[Wingnutt]

I know there was an account of a jug having a bomb rack malfunction causing a 500 pounder not to release, he had to pull out of the dive with it still attached and as a result bent the wings, something like 6 inches at the tip.

[colmbo]

I know there was an account of a jug having a bomb rack malfunction causing a 500 pounder not to release, he had to pull out of the dive with it still attached and as a result bent the wings, something like 6 inches at the tip.

Hmmm.  I can't see how having a bomb hung would bend the wing.  Wings get bent due to the load concentration at the fuselage -- all the weight in the middle type of thing.  A bomb at mid span is supported on both sides, to bend at the bomb rack one part of the wing would have to pull harder than the other part it would seem.

I can see how you would become distracted because of the hung bomb, try to pickle it off and get way to low and have to pull really hard to avoid the earth -- now that could easily bend a wing.

[AquaShrimp]

You don't see how having a 500lb bomb under six or seven g's of force could overstress and bend the metal of a wing?  The force of the bomb is acting like a fulcrum, bending the wing where it attaches to the fuselage.