Author Topic: B-1b (Read 1357 times)

AquaShrimp · « **on:** April 16, 2007, 08:13:47 AM »

I've seen B-1b bombers do rolls at airshows before. What is the g-limit on these aircraft? I think one also did a loop one year at an airshow, but I couldn't tell for sure. I know it did a vertical climb of about 15,000 feet from the deck.

For a bomber almost the size of a B-52, the B-1 sure is an amazing aircraft. Early models were more than capable of flying at mach 2+, but this was limited by redesigning the air intake to be more stealthy. Mach 1 is still achievable on the deck though.

Theres talk of updating the B-1s, which use the same engine as the F-16, with the engines of the F-22. This would double the non-afterburning power of its engines (from 14,000lbs of thurst in mill to 29-33,000 lbs).

Holden McGroin · « **Reply #1 on:** April 16, 2007, 01:50:34 PM »

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...

AquaShrimp · « **Reply #2 on:** April 16, 2007, 03:09:49 PM »

Wow, 7 or 8gs, thats pretty good for the old B1b! Especially since the F-14 could only pull 6.5gs. But then again, the air force knows how to build'em.

Bluedog · « **Reply #3 on:** April 16, 2007, 03:19:47 PM »

Just out of curiosity....what is the G limit of the human frame?

I was under the impression that todays fighter aircraft could hold out for longer than thier pilots can under G load.

AquaShrimp · « **Reply #4 on:** April 16, 2007, 03:25:21 PM »

Depends on duration.

9gs leads to unconsciousness in about 10 seconds.

20 to 40gs can be withstood for less than 1 second.

200gs have been withstood for milliseconds (though the retinas may temporarily detach causing blindness for several hours).

Holden McGroin · « **Reply #5 on:** April 16, 2007, 03:30:46 PM »

The F-14 has little canards that extend at ss speed to unload the tailplanes so that it can pull up at 7.5G at mach 2. 6.5 G is the amount it can hold in a consistant turn without flow seperation.

I've pulled 4 in a Citabria and that wasn't close to design load.

In order to race at Reno, Unlimited warbirds have to be certified to be able to pull 6 G's.

7 or 8 is not out of the question on the design board. I would say the B1's standard flight envelope is a bit more conservative.

Masherbrum · « **Reply #6 on:** April 16, 2007, 03:40:20 PM »

Tex pwns. That is "the Barrel roll, of Barrel rolls".

Gunslinger · « **Reply #7 on:** April 16, 2007, 03:41:14 PM »

I don't think the "bone" can pull that many G's. I do know that overseas the pilots "over G" the air craft all the time wich causes many many head aches to the mait. crews.

AquaShrimp · « **Reply #8 on:** April 16, 2007, 03:49:45 PM »

If I had to *guess*, I would say the Air Force puts the g-limit at 3.5 or 4 on the Bone. The Russian version, the Tu-160, which is a gargantuan airplane, is limited to 2.5gs. But I've seen the Bone do some intense maneuvers at airshows.

Old duke cunningham (crooks don't get their names capitalized by me), pulled either 12 or 14 gs in his F-4 and broke the flap hinges. The F-4 is only rated at 8gs I believe.

Eagle, our resident F-15 pilot, said he once over-g'ed his plane. He said he had to pull all kinds of panels off the plane with the groundcrew to check for damage (translation: he ate icecream sandwhich after icecream sandwhich while relaxing underneath the wing while they checked the panels).

eagl · « **Reply #9 on:** April 16, 2007, 06:01:07 PM »

Shrimp you a funny guy

A B-1 is limited to about 3 Gs. A B-1 would probably break up if the pilot attempted a loop (a loop in a B-1 would probably require 4-5 Gs and the plane would accelerate extremely quickly on the backside) but a roll would not be a problem at all.

As for human endurance, a properly trained person can withstand 9 Gs for significantly longer than 10 seconds, however it is very fatiguing and not a healthy thing to do. With proper anti-G equipment, 9 Gs can be held for quite some time.

Anytime you're over about 4 Gs there is some risk of injury, and above 9 Gs there would be significant risk of injury (broken bones, soft tissue damage, burst blood vessels, etc) especially if it was sustained more than a few seconds. I blew out a disc in my lower back (L5-S1) very early in my flying career even though I was flying the F-15E which is not exactly a high-G sustaining sort of aircraft like the F-15C, F-16, or F-22. Many fighter pilots I know have some some sort of back injury as a result of their flying career.

Spikes · « **Reply #10 on:** April 16, 2007, 06:04:12 PM »

Quote

Originally posted by AquaShrimp
Wow, 7 or 8gs, thats pretty good for the old B1b! Especially since the F-14 could only pull 6.5gs. But then again, the air force knows how to build'em.

b1b aint old

http://youtube.com/watch?v=idtPVZsC0A0

AquaShrimp · « **Reply #11 on:** April 16, 2007, 06:07:29 PM »

Depends on your definition of old. Its 25 years old, thats old for a warplane.

Spikes · « **Reply #12 on:** April 16, 2007, 06:07:59 PM »

http://youtube.com/watch?v=idtPVZsC0A0

not a loop but...

SuperDud · « **Reply #13 on:** April 16, 2007, 06:51:22 PM »

When the 707 came out way back when one of the test pilots did a roll with it when it did an over flight of some buyers. I think the guy lost his job but I bet it was a heck of a ride.

LePaul · « **Reply #14 on:** April 17, 2007, 12:20:22 AM »

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

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