B-52s to be re-engined by Rolls Royce!

[IndyFan]

Will the new engines be one per pylon (total of4) or 2 per pylon (total of 8)

A Rolls Royce engineer who is heavily involved in this project told me last year that going with 8 engines requires FAR less modification and certification work than going to 4, which they almost did at least twice. Those plans were rejected due to the cost. Going with 8 will actually be less expensive and less complex, even though they'll still move to an all new engine management system. The aero and weight and balance will not change much, if at all.

I work almost in the neighborhood of the RR plant where these will be made. The RR facility is the old GM/Allison Engine Company Plant 5, or possibly nearby Plant 8. My Dad worked there (and at Allison Transmission Plant 3) for 45 years, starting in 1943. He retired long before RR took over but he always had a fondness for Rolls, working with them on the TF41 in the A-7 and other projects.

 

[javacontour]

So when that article mentioned a 90 year life cycle, they were referring to the program itself, and not individual aircraft.

So the 52Hs from that time, are still flying?

There are now stories of 3rd generation BUFF pilots. Granddad flew one, dad flew one, and now the adult male son is flying B-52s. It's the family business for some AF families.

 

[4WD]

As I recall, they did fit a B-52 with the engine that was going to be solely for
the Boeing 747, One engine replacing the two on that pylon as a 'test bed'.
IIRC, the one big engine used less fuel than the two it replaced. Don't quote me.

My 2¢

I bet it did … but from what generation? B744 ? Mostly grounded … The B748 uses the GEnX right ?

 

[loneryder]

the oldest versions got retired, but even the B-52H was introduced in 1961

Years ago I went to an airshow at Andrews AFB. It was a hot day and the only shade was under the B-52's wings. I joined others for a bit of shade but it was dripping hydralic fluid like a light rain. I asked one of the AF guys about it and he told me that was normal. They just made sure the fluid was topped off before a mission.

 

[wings&wheels]

I remember when the 4 engine option was discussed. Always wondered if a current generation, high bypass engine would fit with regards to ground clearance, maybe hang it out further forward and higher? Would have been an interesting exercise.

 

[IndyFan]

Years ago I went to an airshow at Andrews AFB. It was a hot day and the only shade was under the B-52's wings. I joined others for a bit of shade but it was dripping hydralic fluid like a light rain. I asked one of the AF guys about it and he told me that was normal. They just made sure the fluid was topped off before a mission.

If a B-52 isn't leaking, it is empty.

 

[BusyLittleShop]

BUFF... Big Ugly Flying Fooker... USAF retired 88 to 98...

 

[MolaKule]

As I recall, they did fit a B-52 with the engine that was going to be solely for
the Boeing 747, One engine replacing the two on that pylon as a 'test bed'.
IIRC, the one big engine used less fuel than the two it replaced. Don't quote me.

My 2¢

Back about '88-'89 when I was at Boeing we proposed a 4-engine refit for the B-52 with GE or P&W engines that used less fuel, but of course provided more thrust, but It was rejected by the AF.

 

[john_pifer]

I remember reading that low-bypass (LBPR) engines are better for high speeds, such as in fighters and supersonic bombers.

The B-52 is pretty fast, as I recall, for a large, subsonic aircraft, but I’m assuming using HBPR turbofans, with their greater frontal surface area, wont affect top speed much?

I also wonder how much range will increase.

Such an incredible machine that was designed in the 1950s!

 

[vavavroom]

The airframe of the B52 was built to last - up to 90 years. They plan on flying them until about 2050. I would think every part other than the airframe has been replaced, often multiple times and with upgraded parts and equipment. An incredible bird.

 

[paulri]

Now that is interesting. I don't think anyone expects modern fighter aircraft built in the 2020s, to last till 2110. Could be wrong on that, although I kind of doubt that. But that's interesting that they had that long of a timeframe.

The airframe of the B52 was built to last - up to 90 years. They plan on flying them until about 2050. I would think every part other than the airframe has been replaced, often multiple times and with upgraded parts and equipment. An incredible bird.

 

[MolaKule]

The U.S. Air Force Is Gradually Rebuilding Its B-52 Bombers From The Rivets Out

In seven years or so, if everything goes according to plan, the U.S. Air Force should get what looks like a new bomber.

www.forbes.com

“When we built the B-52, it was supposed to be a high-altitude nuclear bomber, right? Going to the adversary,” said Maj. Gen. Andrew Gebara, director of strategic plans, programs, and requirements at Air Force Global Strike Command. “Then it became a low-altitude nuclear bomber. And then it became a high-altitude carpet bomber in Vietnam. And then it became a standoff cruise missile shooter in Desert Storm. And then it became a precision strike close air support platform in Afghanistan and Iraq.

“And now we're going to make it the first hypersonic shooter in the American inventory,” Gebara said, referring to the integration testing underway to fit the B-52 with the AGM-183A Air-launched Rapid Response Weapon.

“I don’t think the original plan was to go 75 years,” said Jennifer Wong, Boeing senior director for bomber programs. “But the way the aircraft was designed, it was designed with a lot of structural margin.”

B-52 Engine Replacement Could Keep Bomber Flying Through Its 100th Birthday

Other improvements have the Air Force contemplating smaller air crews.

www.defenseone.com

 

[wpod]

One of my friends was a crew Chief on a B52 during the Cambodia bombings/ Vietnam war, He told me stories that amazing to say the least. I am glad I wasn't there. The people in the military are braver than I could ever be !

 

[wpod]

You don't need modern to bomb third world nations.

 

[vavavroom]

Now that is interesting. I don't think anyone expects modern fighter aircraft built in the 2020s, to last till 2110. Could be wrong on that, although I kind of doubt that. But that's interesting that they had that long of a timeframe.

They overbuilt them probably because they didn't use computers in the design and wanted to be sure the airfrane would be super-tough and last a long time. I'm not sure how much they used to fly B52's way back but now the surely fly them less often. They got many miles to go.

 

[y_p_w]

Both General Electric and Pratt & Whitney competed for this program (the Commercial Engine Re-engining Program). I don't believe it's super sophisticated or anything, as they're replacing engines that haven't been made in decades with small commercial jet engines. I'm sure that all of the competitors would have done fine. The key here wouldn't seem to be performance, but costs now and into the future.

PW800

prattwhitney.com

As industry leaders, we are the proven choice in the commercial market. Our unrivalled expertise in integrating propulsion systems goes beyond just the B-52 airframe. The PW800 supplanted Rolls Royce to power Gulfstream’s long-range, large-cabin G500 and G600 aircraft, and the GTF was selected over the GE Passport to power the Embraer E-Jets E2 family aircraft. We only offer dependable engines with the highest standards.​

​

B-52 Re-Engining | GE Aviation

www.geaviation.com

GE is the only company to have been involved in re-engining U.S. Air Force aircraft three times over. Add in our deep experience powering six strategic bombers, entrenched support of air combat, and the reverence we have for the role we play in protecting this country; and GE is the clear partner to ensure the B-52 is ready at all times for the most critical missions.​

​

 

[IndyFan]

One thing that was important was to keep RR viable as a defense contractor and especially as a military engine supplier.

 

[y_p_w]

One thing that was important was to keep RR viable as a defense contractor and especially as a military engine supplier.

Is the DoD really that concerned about keeping a British company viable? The industry leaders are both American and are usually competing against each other for military sales.

This is also just taking existing commercial engines and adapting them to the B-52.

 

[mk378]

I'm not sure how much they used to fly B52's way back

They were ordered for Operation "Chrome Dome." Every day they would load up several bombers with nuclear bombs and fly them almost to Russia, waiting in international airspace just outside Russian territory in case this is the day that World War 3 breaks out. If not they would fly home and repeat it the next day.

And indeed the USA and USSR did that every day for many years.

So the B-52 was specified that it would be flying a lot of hours. Previous bombers were designed with the understanding they were likely to get enemy fire every mission, so wear-out was unlikely to be an issue.

 

[IndyFan]

Is the DoD really that concerned about keeping a British company viable? The industry leaders are both American and are usually competing against each other for military sales.

This is also just taking existing commercial engines and adapting them to the B-52.

Absolutely. Rolls Royce is a major defense contractor with significant operations in the US, not to mention its US roots. Take a look at their contribution to the F-35B. There would not be an F-35B without Rolls Royce. The lift fan was designed, developed, and is manufactured in Indianapolis, Indiana. Same with engines for the Osprey and C-130, which are the backbone of theater lift capability. Then there's the E2 Hawkeye, and helicopter engines, as well.

And there is much more to it than just installing commercial engines into a military aircraft. The engines will be "militarized," which involves significant engineering to meet various military criteria, particularly in the area of engine controls, but I'm sure in many other areas, as well.