USAF Fund B-52 Engine Replacement

[ORAC]

How many times has this done the rounds over the last 30 years? Is this the first time it has reached the funding stage?

AW&ST: U.S. Air Force Boost B-52 Funding For Engine Replacement

The U.S. Air Force has requested funding and authorization from Congress to launch one of the largest military reengining programs since the Boeing KC-135R Stratotanker.

The service’s fiscal 2019 budget request seeks more than $1 billion through fiscal 2023 for a Boeing B-52 Stratofortress propulsion system replacement program. The initiative would replace the Pratt & Whitney TF33-103, which has powered the H-model B-52 since its introduction in 1960. But unlike the KC-135R refueling aircraft upgrade, which swapped four TF33s for four CFM International CFM56s, the Air Force is shooting for a straight “eight for eight” swap on the B-52, rather than attempting to install four large high-bypass turbofans.

This is a major opportunity for turbofan manufacturers GE Aviation, Pratt & Whitney, Rolls-Royce and potentially Safran, which are now lining up to compete.

The program has been gathering momentum over the past two years, but it received a significant bump on Feb. 12, when the Air Force released its budget proposal. Having now decided to keep the B-52 around until 2050, while replacing Rockwell B-1Bs and Northrop Grumman B-2s with Northrop B-21 Raider stealth bombers, the service’s fiscal 2019 proposal would launch nine new B-52 modernization programs. The largest of them is the reengining, which will be pursued concurrently with a major radar upgrade.

According to budget documents, funding for B-52 modernization will peak at more than $560 million in fiscal 2021. If the engine upgrade is approved and funded by Congress, the service will seek a prime system integrator and engine manufacturer to deliver up to 650 new engines, including spares. The initial buy would be 20 engines for integration and testing on the first two B-52s in the 2022-23 time frame.

GE Aviation tells Aviation Week that it could put forward its latest engine in the required thrust class, the Passport, which powers Bombardier’s newly developed Global 7000 business jet and has been selected for the proposed Global 8000......

Rolls-Royce would offer one member of its BR700 product range, most likely the 15,000-17,000-lb.-thrust-class BR725 that is the engine on Gulfstream’s long-range G650 business jet. Versions of the BR700 power the Air Force’s Gulfstream C-37A transport and Bombardier Global Express-based E-11A Battlefield Airborne Communications Node......

Pratt & Whitney previously has said as it could offer a new engine or a TF33 upgrade package, depending on the requirements..... The company has expressed preference for a TF33 upgrade, but may decide to offer the Pratt & Whitney Canada PW800-series turbofan, depending on whether the Air Force allows foreign participation. The PW800 powers Gulfstream’s latest business aircraft, the 15,100-lb.-thrust PW814 for the G500 and 15,700-lb.-thrust PW815 for the G600.

Safran also has been attending the industry days but has not yet announced its intention to bid......

[Heathrow Harry]

Funny really.. if you proposed a new v large relatively slow, totally unstealthy bomb truck you'd be laughed out of the industry or military

But that's what they need and will need for another 30 years.........

[George K Lee]

It was proposed in 1982, with PW2000s, and was rejected because all the B-52s were to be retired in the 1990s. Rolls tried in the mid-90s, with RB211-535s, and it was turned down because the AF did its sums wrong. (They forgot that gas from a KC-135 costs a bit more than gas at the pump.) Now it's back because there are efficient engines the right size for an eight-engine solution, which makes the engine-out case easier.

[XR219]

Originally Posted by ORAC

Having now decided to keep the B-52 around until 2050, while replacing Rockwell B-1Bs and Northrop Grumman B-2s with Northrop B-21 Raider stealth bombers, the service’s fiscal 2019 proposal would launch nine new B-52 modernization programs.

If they can stretch it out to 2052, then that would make a nice round 100 years of B-52s!

[Mr Mac]

Heathrow Harry
Totally agree, although the market would be very limited, most probably USAF only, and how many air frames would they want / need ?. The B52 has been around all my life, and the way its being upgraded it looks as though it will see me out ! I actually went to see them take off from RAF Fairford during GW1 as I thought (and hoped) that I would never have to witness a fully loaded bomber take off on a war mission again from UK. Sadly wrong on that count, as history has proven. Wonderful old A/C though !

Regards
Mr Mac

[KenV]

Originally Posted by George K Lee

Now it's back because there are efficient engines the right size for an eight-engine solution, which makes the engine-out case easier.

That's not really correct. A single large high bypass engine on the outboard pylons would end up too close to the ground. Some people claim this would cause an engine strike in a cross wind landing, but that's false. The B-52 does not bank into a crosswind. It has steerable landing gear and crabs wings level into a crosswind. The real problem is two-fold: FOD ingestion and wing flutter. In addition the airflow and CG distibution of a four engine layout would be very very different than the 8 engine layout. This would require recertification of every weapon and weapon combination from every store location and combination of store locations on the aircraft. That would require a LOT of very expensive test flying. The more we looked at the four engine solution, the worse it got. It quickly became a non player. The advent of modern engines in the required thrust range designed for biz jets made an eight engine solution possible again. There are still some issues, but they are miniscule compared to the four engine solution.

As for the B-52 vs the B-1, USAF preferred keeping the Bone flying over the Buff. For the past 10+ years USAF has been tearing down and doing deep-dive inspections of the Bone's structure. Sadly, keeping the structure safe to fly much past a single design lifetime is going to be very difficult and horrendously expensive. So the Buff gets the nod over the Bone and the Buff's new engines will pay for themselves if the Buff keeps flying for another 20-25 years. And to ensure that, USAF is investing heavily in corrosion inspections, abatement, correction and protection on the Buff. As for the B-2, that fleet is just too small to effectively manage and its stealth coating systems ludicrously difficult and expensive to maintain, so keeping it going after the B-21 comes on line would be foolish.

[cavuman1]

Suck, Squeeze, Bang, Blow

Back in the Second Millennium, mid-1990's to be slightly more exact, my then-wife was a Legislative Director for Speaker of the House Tom Foley (D-WA). Part of her job responsibilities included being the Speaker's Pentagon Liaison. She enjoyed this responsibility since it allowed her leave the Capitol, cross the mighty Potomac River, disembark upon the scented soil of the Commonwealth of Virginia, get lost in the World's largest office building, and spend several hours each week gazing at high-ranking Air Force officers in their freshly-pressed, medal-bedecked dress uniforms.

I returned home one evening to our Maryland digs to find her in a greater than usual state of agitation and distress. "What's the trouble?", I asked, fearful that she had just gotten the call to report to the secret bunker beneath the Greenbrier Hotel in West Virginia because we were under nuclear attack and she didn't have the right color shoes. "The House Armed Services Committee has indicated that they would approve the funds necessary to re-engine the KC-135 Tanker, the Pentagon is begging for the upgrade, and I've got to write the Bill!", she exclaimed. "It'll be for several Billion with a capital B dollars! And I don't even know how a jet engine works!", she whispered, growing increasingly crestfallen.

Seizing the opportunity to play the role of a veritable modern day Socrates, I asked in an even voice "Just out of curiosity, O Love of My Life, how do you think a jet engine works?" She responded without hesitation: "It spins around and sucks the plane forward like a giant vacuum cleaner..." I ran into our kitchen to grab a cold beer and to hide my guffaws from my aviatrix ingénue.

It came to pass that she authored the multi-billion dollar bill that caused some 361 KC-135E's to be refit with GE/SNECMA CFM-56 turbofan engines to metamorphose into KC-135R's. Apparently this was a very efficacious modification which gave substantially greater payload capacity with significant fuel savings.

Epilogue: Though I never was able to tutor my former bride about the simple concept of Suck, Squeeze, Bang, Blow, she did exhibit a natural ability for two of those operations: she would bang me on the head with a frying pan while raining blows over my unprotected face!

Sic Semper Tyrannis...

- Ed

[Argonautical]

I remember talking to a B-52 pilot at an airshow years ago. I asked him why they didn't replace the 8 engines with 4 new ones like they did with the KC-135. He wasn't impressed with the proposal and asked me if I would want to lose one engine out of 4 on a fully laded take-off!

[KenV]

Originally Posted by Argonautical

I remember talking to a B-52 pilot at an airshow years ago. I asked him why they didn't replace the 8 engines with 4 new ones like they did with the KC-135. He wasn't impressed with the proposal and asked me if I would want to lose one engine out of 4 on a fully laded take-off!

What?!! As opposed to one engine out of TWO fully loaded on the vast majority of modern airliners?

But it does bring to mind the dreaded 7-engine approach in a B-52.

[ORAC]

What?!! As opposed to one engine out of TWO fully loaded on the vast majority of modern airliners?

On the other hand, they have automated flight controls and flight surfaces designed to kick in and take the stress....

[Just This Once...]

The replace 8 with 4 idea was a non-starter as aerodynamically the aircraft was not built with that in mind. VMCA issues abound when the OEI is now equivalent to a simultaneous double-hush on a pylon pair.

[Bevo]

Originally Posted by KenV

As for the B-52 vs the B-1, USAF preferred keeping the Bone flying over the Buff. For the past 10+ years USAF has been tearing down and doing deep-dive inspections of the Bone's structure. Sadly, keeping the structure safe to fly much past a single design lifetime is going to be very difficult and horrendously expensive. So the Buff gets the nod over the Bone and the Buff's new engines will pay for themselves if the Buff keeps flying for another 20-25 years. And to ensure that, USAF is investing heavily in corrosion inspections, abatement, correction and protection on the Buff. As for the B-2, that fleet is just too small to effectively manage and its stealth coating systems ludicrously difficult and expensive to maintain, so keeping it going after the B-21 comes on line would be foolish.

Ken - it's a shame that the Bone structural upgrades will be overly expensive. I'm not sure many folks appreciate the B-1's capabilities. The B-1 has a number of advantages over its B-2 and B-52 counterparts. Its internal payload capacity is the highest at 75,000 pounds, which is 5,000 more than the B-52 and 25,000 more than the B-2. Reaching Mach 1.2, it is the only supersonic heavy bomber the U.S. possesses. It is also the cheapest to fly at $63,000 per hour of flight, compared with $72,000 for the B-52 and $135,000 for the B-2.

Furthermore, as a testament to its preference among U.S. commanders, from October 2001 to September 2012 the B-1 flew 10,940 combat sorties over Iraq and Afghanistan versus the B-52's 2,891 and the B-2's 69. In fact, the B-1 dropped 40 percent of the bomb tonnage in the first six months of the war in Afghanistan, and, by 2012, had released 60 percent of the weapons overall.

Moreover, if the United States were to find itself in conflict in Asia, for example, shorter-range aircraft fighters stationed at bases in Japan and South Korea would be vulnerable on the ground to long-range missile strikes. But the B-1, with its longer-range and ability to carry 24 Joint Air-to-Surface Standoff Missiles (JASSMs), could operate from far-off bases and beyond the limits of advanced air defense systems.

[Piltdown Man]

Any engine? Or only engines manufactured in the US?

PM

[Buster Hyman]

Originally Posted by XR219

If they can stretch it out to 2052, then that would make a nice round 100 years of B-52s!

So, in comparison, who would be interested in taking one of these into combat today?

[etudiant]

Originally Posted by Buster Hyman

So, in comparison, who would be interested in taking one of these into combat today?

Has the B-52 been in combat in the last 40 years?
Dropping bombs on designated targets, absolutely, but no combat.

[Dan Winterland]

I should think the crew of this B52 would have considered themselves to have been in combat.



It's the remains of a B52 in a lake in Hanoi, still visible today.

[tdracer]

Ken
I fear the USAF is going to find out just how expensive it is to retrofit modern FADEC engines onto an analog airplane and discover they would have better off fixing the B-1 structures.
They will basically need to update the B-52 as comprehensively as they did the C-5 - all new avionics to go with those fancy new engines. That was a major factor in killing the PW2000 early on, and it's FADEC was primitive compared to the new FADECs. I don't think we got far enough with the RB211-535 to look at aerodynamic and flutter effects, but systems wise it would have been relatively easy (the RB211-535 was basically an analog engine even though it was fitted to a digital 757).
Heck, by the time it's all said and done, they might be cheaper turning a 747-8F into a bomber - it's new, fuel efficient, carries way more than the BUFF, and would be just as survivable...

Edited to add:
Dan, check the dates, that was more than 40 years ago...

[West Coast]

Has the B-52 been in combat in the last 40 years?
Dropping bombs on designated targets, absolutely, but no combat.

Dropping bombs on guys who want to kill you is combat. That they didn’t get shot up/down likely speaks to tactics, counter measures and luck.

[TWT]

The Hanoi B-52 was shot down on December 27th, 1972

[George K Lee]

TDR - That's a concern of mine too. A bit like fitting a '58 Chevy with a 2018 Honda Civic engine.

The secondary concern is that someone's going to think it's easy or (if it's done competitively) underbid to get the work.