Tarantine
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B-52 Airframe Life

Tue Dec 14, 2004 9:34 am

I have read that the B-52 will possibly fly for another 30yrs or so. I was wondering how much airframe life is left in the 52. I thought boeing designed the plane for approx 10,000hrs (unsure of the cycle life). Anyone know how many sorties a B-52 accumulates annually?
 
EMBQA
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RE: B-52 Airframe Life

Tue Dec 14, 2004 10:10 am

I don't know. But the B-52 is one of the finest planes ever built. I read somewhere that there is one B-52 that has been flown by a Grandfather, a Father and a Son. 3 Generations all to fly the same plane..!!!
"It's not the size of the dog in the fight, but the size of the fight in the dog"
 
grom365
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RE: B-52 Airframe Life

Thu Dec 16, 2004 5:30 am

There are a couple of things that could keep the B-52 - or any old airplane - flying past it's "design life".

1. Design tools. Planes designed back in ye olden days didn't have the advantage of finite modeling, etc., that today's engineers do. For the same flight profile(s) and service life requirements, today's aircraft use thinner gages and more efficient structural designs because we have the tools to more accurately predict stress and loads distributions than in the past. In other words, analyze the design of an older plane with today's tools, and you'll find many of them have greater margins than originally calculated.

2. At one point in its life (I think it was the 'D' model), the flight profile changed from a HI-HI-HI to a HI-LO-MED. This caused the wing and tails to be redesigned and beefed-up for the increased loads experienced at high speed and low altitude. Now that the "standard" flight profile no longer includes low level ingress, you get an increase in fatigue life.

3. There will likely be some kind of service life enhancement program to deal with fatigue critical areas. This may range from adding doublers to re-winging the plane. Something like this would happen during a phased maintenance period, and while expensive, would be a lot cheaper than building a new bomber from scratch.
 
Woodreau
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RE: B-52 Airframe Life

Thu Dec 16, 2004 7:27 am

Just from hearing the gossip, I understand the Air Force intends on keeping the B-52 around until 2040, which means when they'll be about 80 years old when they finally retire them.
Bonus animus sit, ab experientia. Quod salvatum fuerit de malis usu venit judicium.
 
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vzlet
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RE: B-52 Airframe Life

Thu Dec 16, 2004 7:57 am

What I find amazing is that the B-52 first flew less than 7 years after the end of WWII.
"That's so stupid! If they're so secret, why are they out where everyone can see them?" - my kid
 
LeanOfPeak
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RE: B-52 Airframe Life

Thu Dec 16, 2004 3:55 pm

According to GlobalSecurity.org, the limiting part for the economic service life of the B-52 is the upper wing surface, which will supposedly last to between 32,500 and 37,500 hours. Using that as the limit, they anticipate that high-time airframes should start being retired in 2030, medium-time frames in 2040, and the required number of frames can no longer be sustained by 2044, though some of the lower-time frames could theoretically operate to 2050 or beyond. The last would theoretically be retired only 8 years short of the type flying for a century.

http://www.globalsecurity.org/wmd/systems/b-52-life.htm.
 
DeltaGuy
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RE: B-52 Airframe Life

Thu Dec 16, 2004 7:19 pm

The G's served in Desert Storm, yet were retired shortly after....how old were they? They didn't seem to be that old, right up there with their H brothers in currently....seems like they had some life in em, especially seeing how the H is going to serve far longer than any other B-52 variant out there.

DeltaGuy
"The cockpit, what is it?" "It's the little room in the front of the plane where the pilot sits, but that's not importan
 
grom365
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RE: B-52 Airframe Life

Thu Dec 16, 2004 8:23 pm

The 'G' model was retired not just because of fatigue life, but because of arms reduction treaties. The 'H' models are conventional weapons only.
 
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vzlet
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RE: B-52 Airframe Life

Fri Dec 17, 2004 2:27 am

Grom365,
Aren't the "H" models the sole platform for ALCMs, including the original nuclear version of the AGM-86 as well as the AGM-129?
"That's so stupid! If they're so secret, why are they out where everyone can see them?" - my kid
 
citation501sp
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RE: B-52 Airframe Life

Fri Dec 17, 2004 7:29 am

Yes the B-52H can still carry out its original nuclear mission. Although they no longer are kept waiting on alert for nuclear attack. They can be changed over in a few hours.

During the seventies and eighties, two wings of B-52H's the 5th BW and the 319th BW took over the conventional bombing mission from the B-52D's, "The Strategic Projection Force". During Desert Storm the roles were reversed the H's stood nuclear alert while the majority of G's did conventional bombing.

501SP
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N328KF
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RE: B-52 Airframe Life

Fri Dec 17, 2004 7:37 am

Definitely not like the old days where they kept some of them in the air all the time.
When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt
 
57AZ
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RE: B-52 Airframe Life

Fri Dec 17, 2004 10:59 am

Nope, but the E-4B "Doomsday" plane still sits on 24-hour Ground Alert. Airborne Alert ended with the fall of the Union of Soviet Socialist Republics.
"When a man runs on railroads over half of his lifetime he is fit for nothing else-and at times he don't know that."
 
PanAm707320B
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RE: B-52 Airframe Life

Mon Dec 20, 2004 8:27 pm

VZlet - Not quite. The B-52 first flew in 1954 whereas WW2 finished in 1945. Still an amazing achievement however.
 
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vzlet
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RE: B-52 Airframe Life

Mon Dec 20, 2004 10:26 pm

(The Boeing site gives April 15, 1952 as the date.)
"That's so stupid! If they're so secret, why are they out where everyone can see them?" - my kid
 
PanAm707320B
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RE: B-52 Airframe Life

Mon Dec 20, 2004 11:03 pm

Vzlet - Agreed, the flight of the first prototype (YB-52) was on April 15th, 1952. The flight of the first production aircraft (B-52A) was on August 5th 1954. Anyway, we're splitting hairs here as it's still a hugely impressive service life and a fantastic aircraft.

Regards
Alex
 
Venus6971
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RE: B-52 Airframe Life

Wed Dec 22, 2004 3:13 am

Lets remember, the Buff was designed by the same guy's who designed the B17,and B-29. They had something going for them. It is a credit to them to build or over engineer the structures that they are still flying. The KC-135 and 707 also of these designers will soldiering on for at least 20 more year's.
I would help you but it is not in the contract
 
IL76TD
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RE: B-52 Airframe Life

Wed Jan 05, 2005 11:58 am

Are the engines used on present day Buffs the same engines that were used on the originals.

Have they ever though of reengining these aircraft with modern engines. Given the engine tech available today it seems like mission capability could be increased quite heavily if they were to outfit the planes with 4 modern engines
 
dl021
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RE: B-52 Airframe Life

Wed Jan 05, 2005 1:00 pm

No.. They originally used turbojets, and the last pure jet BUFF was flying for NASA until recently.

Now they use TF-33 medium bypass turbofans. There currently is a study going on and a push to re-engine the BUFF with CFM-56 derivatives to give them better range and reduced maintenance.

I am waiting for some 717 fanatic to start saying the USAF should re-engine with BR-714's to give the engine another user and make the B717 more attractive in some way! Big grin (Hey, I just made a B717 reference in MilAv...is that some sort of record? ) Wink/being sarcastic Smile/happy/getting dizzy

[Edited 2005-01-05 05:02:07]

[Edited 2005-01-05 05:02:30]
Is my Pan Am ticket to the moon still good?
 
sovietjet
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RE: B-52 Airframe Life

Wed Jan 05, 2005 1:02 pm

I wish they still had the original engines. What were they J-57s? I believe they use the JT-3D today. If they still had the old engines...we would see something like this when one takes off....

 
dl021
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RE: B-52 Airframe Life

Wed Jan 05, 2005 1:21 pm

Ah the old smoky water injected Pratt & Whitney J-57P-19W/29W/29WA takeoff.

"Peace is our Profession!"


The "H" models use the TF-33's just like the 707 and KC-135E/E-3 models.
Is my Pan Am ticket to the moon still good?
 
SATL382G
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RE: B-52 Airframe Life

Wed Jan 05, 2005 2:29 pm

The B-52 has never been reengined! Those examples flying today are flying with the same engine type they left the factory with. B-52Hs had the TF33s from day one, the earlier models had the J-57s.

There have been various proposals to reengine the BUFF, notably with the RB211, but none has come to anything.

regards
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

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