B-1b

[Wolfala]

The 707 roll with interview.

http://www.aviationexplorer.com/boeing_707_roll.wmv

[SuperDud]

Thanks for posting that wolf, good to know the guy didn't end up losing his job.

[Excel1]

Originally posted by LePaul
Holy 757 did you see the video after the inverted B-1B you posted?

http://www.youtube.com/watch?v=fYZOByowrlU

I saw an RNZAF 757 do that high speed pass into a near vertical climb manoeuvre at an air show a couple of years ago. As it got slower and slower and topped-out I was half way expecting to see a hammerhead on the end of it...but it levelled off, although it looked pretty mushy.

Judging by the way they throw their 757's around I think the RNZAF are missing not having the nimbler faster toys

[mars01]

Gs are not all in all bad,

I have pulled 7gs max in the Pitts and -4 which translates in to -5 when you calculate the fact that you start out at +1.  I make it a point to stay within the G limits of the aircraft for obvious reasons.  And only occasionally hit these limits mistakenly.

Not sure if the military builds to the same specs, but the General Aviation G rating is such that it will allow for a 1 1/2 times the Gs before some kind of potential structural failure.

So in the pitts that is rated for +6 , -3.  The structure was rated at 6, -3 because at 9 and -4.5 Gs something failed.


As for the Gs while rolling, if done right they should be all positive and not exceed 2gs.

For a loop it is not necessary to pull more than 3.5 to 4 gs all of which are utility category numbers.

The problem is, FK up the loop or roll and you could find yourself over G very quickly and that is a big problem.  

You also have to look into high G cycles and the materials being stressed.  Many of the military aircraft out there that have aluminum spars etc have a set number of G cycles and after that the aluminum is weakened to the point of failure.  Do a search on Beech T34s and wing spar failure.

[AquaShrimp]

I was thinking the Pitts was rated for more than 6gs.  Kinda disappointed now.  I believe Patty Wagstaff has pulled 12 or 13 gs in her Extra 300.

Yeah, aluminum has what is known as a fatigue memory.  It is permanently weakened after its specifications are exceeded.  However, the Soviets used to add some type of rare earth element to their aluminum, to make it stronger for aircraft use.

[mars01]

Mine is a 2B, I believe the 1s have a bit higher G rating.  While many of the components can take more Gs it is what they certified it at.  What are you disappointed about?  It still does all the maneuvers.    I have flown an Extra 300 and the Pitts S2C comes closer to it with the stiffer wing.

BTW the extra is only rated and certified for +/- 10 Gs

[AquaShrimp]

At 10gs, is it even possible to keep your eyes focused on a g-meter?  Extra 300s dont have flight control computers, so it would be up to the individual pilot to limit themselves.

[mars01]

You have to remember these are not sustained G loads.  If they hit 10 Gs, and they do, it is only for a couple of seconds.  But it still takes it's toll.

I know a guy who flies an Edge 540 and when he comes down his G meter is usually +10 -9 and when you look at him his eyes are all red and watery etc.  The negatives at that level are what really hurt, or so I am told.  I know -4 is uncomfortable but not a big deal, unless your doing back to back outside maneuvers.

[festus]

Originally posted by Bluedog
Just out of curiosity....what is the G limit of the human frame?
 

"in the verticle axis...83G known to produce fatal incapacitation". This is a comment in a F-16 mishap investigation report from November 2006.

[1K3]

Originally posted by Holden McGroin
A loop or a roll doesn't take a tremendous amount of G's.  



I would venture a guess that the B1 could pull 7 or 8...

God I HATE the sound of axial-flow jet engines:furious

[Hazzer]

A roll in a 707 is only  2G 's