The Mother of All Bombers...

[Woobie]

Grew up in Dayton and remember when the XB-70 flew into Patterson Field. First time Dad took me to the museum was 1965, at Patterson Field. When the new Air Force Museum opened, they towed all the aircraft up highway 444 to Wright Field.

Man, I'll bet that was a sight.

 

[SnoopLoggyDog]

1970 move to the new Air Force Museum. The above picture is on Ohio Route 444 at Huffman Dam. XB-70 is at 1:38 in the video.

[video=youtube;x2qVaTDYw78]https://www.youtube.com/watch?v=x2qVaTDYw78[/video]

 

[jimbo-indy]

As long as we are talking about old bombers of note, my father in law was a bombardier on a B29 in WW2. Stationed on Tinian Island while the Enola Gay was waiting the the USS Indianapolis to deliver the bomb. He was on a ship headed for home when word of the "BOMB" was broadcast. Took my son and grandson to Wright Pat to see the B29 on display there. Made a big impression on both to see the plexiglass nose and envision their grand father/great grandfather sitting there working the bomb sight while Jap fighters and AA are shooting at you. He was about 20 yrs old at the time. His plane was the "Big Time Operator" which had quite a history itself. Found a model of it with the nose art and all.

 

[AtTheMurph]

I believe the only airframe still flying is the H model. All others were destroyed in the desert by being cut into parts that were visible to Russian satellites during the treaty to make us more vulnerable.

A long time ago, Pratt & Whitney Aircraft offered to re-engine the B-52 by taking the double pods and replacing them with single more modern engines. The air force said no. I am guessing fuel burn was not as much an issue as the added engine redundancy if an engine has to be shut down.

They probably declined the retrofit because the decision makers had equity positions in the jet fuel procurement companies. Wouldn't want better fuel economy because that eats into profits.

 

[SnoopLoggyDog]

I believe the only airframe still flying is the H model. All others were destroyed in the desert by being cut into parts that were visible to Russian satellites during the treaty to make us more vulnerable.

A long time ago, Pratt & Whitney Aircraft offered to re-engine the B-52 by taking the double pods and replacing them with single more modern engines. The air force said no. I am guessing fuel burn was not as much an issue as the added engine redundancy if an engine has to be shut down.

Multiple reasons for staying with the eight engine configuration. The US Air Force Has Taken Another Step Toward Re-Engining its B-52s - The Drive

[FONT=&amp]“The last time the USAF researched what it would need out of an engine program was 2014, when it concluded that new powerplants would need to save between 10-25% in fuel consumption, and would have to go 15-25 years before the first deep overhauls of the engines are required. The question of which engine would best fit this requirement remains, as well as whether four large engines or eight smaller ones (even six, under some concepts) would be best.[/FONT]
[FONT=&amp]
“One area of concern is if new pylons would be needed to accommodate powerplants mounted in new locations under the BUFF’s wings. Such a requirement could result in a costly re-engineering of the B-52’s wings. With four larger engines, such as GE's CF6 (called the F138 on the C-5M) or engines similar in size to the Pratt & Whitney PW2000 (the F117, in use aboard the C-17A) wing height and rudder authority for engine-out operations remain a question. As as result, costly flight control and avionics upgrades might be needed to accommodate their use, beyond the need for potential structural upgrades to the B-52’s wings.[/FONT]
[FONT=&amp]
“With this in mind, probably the easiest option is eight compact high-bypass turbofans fitted to the aircraft’s existing pylons in re-contoured dual-nacelle pods. The Rolls Royce BR725 powering the Gulfstream 650 is one contender, as is GE’s Passport 20 found on the Global Express 7000 and 8000. If the Air Force decides to push forward with an official RFP for an engine swap on the B-52, other entrants will surely emerge.”[/FONT]

 

[Thor]

One of the advantages of the old jets was almost instant throttle authority. It's why at the initial fights on an F4 could out accelerate an F15. Instant go boot vs wait for the spool. After that though...

They may just re-engine the BUFF with an updated version of the current engine. Other than just fitting the existing shoe there are major concerns with other options not meeting the power generation requirements.

 

[Alamo]

Another problem with reengining is all the integration effort required. You have develop new flying procedures for the plane because it now has a new performance envelope, and you have to develop that for every kind of flight profile, from clear day hot weather to snowy frozen to rain etc. Air-to-air refueling would have to be recharacterized and procedures developed to account for changes in the BUFF's performance. Also emergency procedures have to be redeveloped, and for when all else fails, the crew ejection process will have to be evaluated for different performance profiles.. Then all the crews need to be transitioned (re-trained) to the new procedures. Maintenance and logistics people need to be retrained, and new parts and processes accounted for.

IIRC the BUFF can handle more types of weapons than either the B-1 or B-2 (or any other aircraft). Everyone of those weapons, in all their variants, will have to evaluated and requalified on the new configuration for the BUFF.

There are a lot costs beyond hanging new engines on the wings that come with a program like this, and they have to be paid for upfront, regardless of whether predicted savings come to pass or not.

 

[SEIndSAM]

ISIS resurgent in Afghanistan despite being hit by largest non-nuclear bomb | Fox News

 

[Alamo]

This is an interesting article on some of the non-obvious effects of trying to reegine the B-52: Old Dog, New Engines: The Truth about a B-52 Re-Engine - angle of attack

 

[Thor]

Seek Eagle...it isn't cheap or quick. But it may be less than trying to replace the BUFFs capabilities with existing or new airframes.

 

[SnoopLoggyDog]

This is an interesting article on some of the non-obvious effects of trying to reegine the B-52: Old Dog, New Engines: The Truth about a B-52 Re-Engine - angle of attack

Excellent article. It has many good points and includes the idea of replacing all the TF-33s in the USAF inventory, with a new Commercial Off-The-Shelf engine. Thanks for sharing.

 

[rob63]

I was reading a book about aviation during WWI and came across a bomber that I had never heard of before, the Tarrant Tabor. It was developed at the end of the war by a company that had never built an aircraft before, with only 1 ever built. A six-engined triplane, it nosed over on its first take-off attempt, destroying it and killing the pilots. They used to say that if a plane looks right, it probably is. This seems to confirm that the opposite was true as well.

 

[Alamo]

A little update the the B-52 re-engining effort. I missed this when it came out last month, I don't always read my Air Force Magazine right away....

USAF Releases B-52 Engine Replacement RFP, Award Expected July 2021

The Air Force wants fuel efficiency savings of about 30 percent on the new powerplants versus the in-use Pratt & Whitney TF33 engines, and reliability such that the engines never have to come off the B-52 for service during the bomber’s remaining lifetime. This in turn will sharply diminish or eliminate the need to stockpile large quantities of parts, resulting in further savings. The Air Force has said that it expects fuel savings will pay for the cost of the re-engining program, which would also drive a reduction in maintainers assigned to the airplane. With the fuel efficiency, USAF is also looking for an increase in persistence or range of up to 40 percent.

It appears the other performance requirements for the engine are to match the existing TF-33s which should help avoid the problems of changing the flying characteristics of the B-52 too much (other than range).

Twenty engines to start with for prototyping, 608 engines total for 76 BUFFs. GE, Raytheon, and RollsRoyce are the competitors. RR has already said that if selected they will build the engines in Indianapolis, I believe that's the former Allison, no?

 

[KellyinAvon]

A little update the the B-52 re-engining effort. I missed this when it came out last month, I don't always read my Air Force Magazine right away....

USAF Releases B-52 Engine Replacement RFP, Award Expected July 2021



It appears the other performance requirements for the engine are to match the existing TF-33s which should help avoid the problems of changing the flying characteristics of the B-52 too much (other than range).

Twenty engines to start with for prototyping, 608 engines total for 76 BUFFs. GE, Raytheon, and RollsRoyce are the competitors. RR has already said that if selected they will build the engines in Indianapolis, I believe that's the former Allison, no?

They were talking about replacing the engines on the BUFF back when I was sporting BDUs and no where close to Blue-ID Mafia. TF-33s been around a long time, of course so has the BUFF.

 

[indyartisan]

Amazing that B 52s are still in service.
I flew a simulator at Wright Patterson in the 60s.
It must be the best hardware the Air Force ever procured.
The last one I saw up close looked like crinkled up aluminum foil from who knows how many flights.

 

[Alamo]

They were talking about replacing the engines on the BUFF back when I was sporting BDUs and no where close to Blue-ID Mafia. TF-33s been around a long time, of course so has the BUFF.

The difference this time around is that there is an actual RFP on the street with an acquisition plan and decision date. I think this one will go through.

I forgot to add to my post above, I believe another requirement/advantage to the new engine will be the ability to generate a lot more electrical power so more electronic goodies (frickin' lasers!) can be added to the BUFF.

 

[KellyinAvon]

The difference this time around is that there is an actual RFP on the street with an acquisition plan and decision date. I think this one will go through.

I forgot to add to my post above, I believe another requirement/advantage to the new engine will be the ability to generate a lot more electrical power so more electronic goodies (frickin' lasers!) can be added to the BUFF.

Lasers? That brings a whole new meaning to ARC LIGHT!!

 

[rob63]

A little update the the B-52 re-engining effort. I missed this when it came out last month, I don't always read my Air Force Magazine right away....

USAF Releases B-52 Engine Replacement RFP, Award Expected July 2021



It appears the other performance requirements for the engine are to match the existing TF-33s which should help avoid the problems of changing the flying characteristics of the B-52 too much (other than range).

Twenty engines to start with for prototyping, 608 engines total for 76 BUFFs. GE, Raytheon, and RollsRoyce are the competitors. RR has already said that if selected they will build the engines in Indianapolis, I believe that's the former Allison, no?

Yes, it is the former Allison. It would be awesome if Rolls Royce were to win!

 

[actaeon277]

Engines that won't have to be pulled for maintenance...
Sounds "Pie in the Sky" to me.

What will probably happen, is they will get their engines that don't get pulled, but they will just make it harder to fix, and more costly.

 

[NKBJ]

Someday I'd like to build the B52 model still sitting in the box on the shelf, hang it from the ceiling and have Slim Pickens beneath it with hat in hand, on his way to target.