Should the USAF B-52 have used engines, from the soon to be retired KC-135, replace its smoky JP-guzzling engines?

LTC Private RallyPoint Member — Fri, 18 Mar 2016 12:13:41 -0400

The Air Force is keeping the B52 flying until 2040. They have upgraded the plane but they still have the older engines on them. The Air Force, with our new meager budget, needs to save money and save fuel too. One idea that has not been discussed is using the existing KC-135 powerplants already paid (NSN) for and sitting there or going there soon to DM, AFB. We can retrofit our B-52s for cheap!

Response by MAJ Private RallyPoint Member made Mar 18 at 2016 12:23 PM

MAJ Private RallyPoint Member — Fri, 18 Mar 2016 12:23:47 -0400

Seems like a good idea if it'll work.

Response by PO3 Steven Sherrill made Mar 18 at 2016 12:48 PM

PO3 Steven Sherrill — Fri, 18 Mar 2016 12:48:29 -0400

The JSF is a money pit. One money pit per customer per decade.

Response by Col Joseph Lenertz made Mar 18 at 2016 1:20 PM

Col Joseph Lenertz — Fri, 18 Mar 2016 13:20:21 -0400

Yes, but. The idea has been around a while, as your photos of the "tall-tail" Edwards AFB "D" model show. Replacing the inboards is easy, as it doesn't create a dangerous yaw problem in an Engine Failure On Takeoff situation. To replace the outboards, you have to replace the rudder, yaw damper, and develop an Engine Failure Assistance System (EFAS) that automatically (faster than a human can) deflects the (new, larger) rudder when an outboard engine fails during takeoff. So, yes, but it's more expensive than first glance.

Response by SPC Darren Koele made Mar 18 at 2016 5:22 PM

SPC Darren Koele — Fri, 18 Mar 2016 17:22:47 -0400

Please forgive my ignorance, Major, but are the similarities in power (thrust to weight ratio, and other essential factors, etc) close enough that such a change is feasible? Probably a stupid a question because I assume you wouldn't propose it if the differences were too vast. I just want to know to satisfy my curiosity. I would ask my brother with his aerospace engineering degree, but he gets geeked up and doesn't understand that I don't comprehend engineering speak.

Edited:
To add to my question for specificity, if the KC-135 engines are easier on fuel, is it because of design or does it have less power? Would they have to sacrifice payload to accommodate a "weaker" engine set? And if they are "weaker" (I'm starting to wish I knew a more appropriate term, sorry), would the current payload capacity of the B-52 reduce the flight time or cruise speed of the aircraft? Or am I just completely become unhinged, off my rocker, or asking all the wrong question? That's kind of the direction I wanted my initial post to go. Sorry for all this. Sometimes my ignorance breeds curiosity even if I won't understand all the science behind it.

Response by 1SG David Williams made Mar 18 at 2016 10:33 PM

1SG David Williams — Fri, 18 Mar 2016 22:33:29 -0400

Great Idea

Response by MSgt Private RallyPoint Member made Mar 18 at 2016 11:07 PM

MSgt Private RallyPoint Member — Fri, 18 Mar 2016 23:07:10 -0400

I was never maintenance. However, what ever happen to slapping duck tape on them? I thought that's how they kept the F4 flying for so long. Lmao

Response by Capt Seid Waddell made Mar 18 at 2016 11:33 PM

Capt Seid Waddell — Fri, 18 Mar 2016 23:33:18 -0400

Of course we should.

Response by SSgt Jim Gilmore made Mar 19 at 2016 1:09 AM

SSgt Jim Gilmore — Sat, 19 Mar 2016 01:09:02 -0400

How much consideration have you given to the fact that ALL the B-52s would require complete re-winging? Then after that is done you must keep even closer tabs on the stresses placed on the rest of the airframe to maintain reliability. I agree we need to keep the BUFFS flying and we need the A-10 to be kept up. We need to dump the F-35 since tests indicate it is not cutting the mustard in a lot of tests...like repainting the damn fuel trucks to keep the fuel cooler? Your poll is technically flawed but I do understand your thought train.

Edit: I was a KC and BUFF mechanic and crew chief for 7 years, a machinist for 3 years and air traffic controller for 2 years.

Response by PO2 Steven Erickson made Mar 19 at 2016 12:05 PM

PO2 Steven Erickson — Sat, 19 Mar 2016 12:05:59 -0400

Let me get this straight...

"They" want to take THE most successful design - based on service length and mission adaptability - and pull it apart and reassemble it with different parts from a completely different aircraft, to save money on gas?

I'm not a pilot, nor an engineer, but one thing I do know from operating a nuclear submarine older than I was is this... IF IT AIN'T BROKE, DON'T FIX IT and NOTHING IS "FUNCTIONALLY EQUIVALENT" IN THE LONG RUN.

Response by SSgt Donnavon Smith made Mar 20 at 2016 1:20 PM

SSgt Donnavon Smith — Sun, 20 Mar 2016 13:20:41 -0400

Back in 95 when I was at Barksdale they sent in a team of engineers to look at the feasibility for reengining this included moving the guys from downstairs up to the two rear facing empty seats. This was needed to add an APU since the new engines would not have cart start capabilities.

Response by SrA Matthew Knight made Mar 21 at 2016 5:47 PM

SrA Matthew Knight — Mon, 21 Mar 2016 17:47:04 -0400

I've always thought it would be interesting to see the B-52 with newer engines. Could use the ones from a KC-135 on the in board and the ones from a 737 with the flat bottoms for ground clearance on the outboard. What others have said about all the other things that would have to be factored in makes me wonder if it would really work though.

Response by MSgt Michael Lane made Mar 22 at 2016 10:46 AM

MSgt Michael Lane — Tue, 22 Mar 2016 10:46:34 -0400

Not being an engineer I’m not qualified to make an educated judgment on this but I did stay at a holiday inn express once so here it goes. The 135 has a completely different mission profiles than the B-52 (I know captain obvious right) I would wonder about wing load the B-52 has to fly at 100ft to 50,000ft. The 108 engine has power twice or 3X that of the current engine. Which would be putting way more stress not only the pylon assy itself but the wing and wing boxes? The B-52 is on its way out the fact is it cannot survive in a modern battle field. (Not sure if any of our bombers can). I think what the Air Force needs is a medium range bomber like the old F-111 that is what is missing from the inventory.
My other point is the military is not about money, or efficiency the old rule 1 is none and 2 is one still applies. This plane was made for a single task not to be gas efficient doing it.

Response by Col Private RallyPoint Member made Mar 22 at 2016 11:20 AM

Col Private RallyPoint Member — Tue, 22 Mar 2016 11:20:12 -0400

As Col Lenertz states ... not just a straight R&R issue. The CFM-56 might not be the right answer either as the C-5Ms have the F117-PW-100 fans off the C-17, even more efficient than the CFM-56. A re-engining might be in store, but lets not make the same mistake that was made with the KC-15E and assume an existing surplus engine is the answer only to retire it early because the 80s technology of the 135R models is growing old.

Response by 1stSgt Nelson Kerr made Mar 22 at 2016 1:24 PM

1stSgt Nelson Kerr — Tue, 22 Mar 2016 13:24:24 -0400

Yes but don't let USA project management anywhere net it and make it a fixed price pay as you go contract.

Response by MSgt Alex Taylor made Mar 27 at 2016 12:47 PM

MSgt Alex Taylor — Sun, 27 Mar 2016 12:47:06 -0400

At one point, the USAF tested the CFM-56 engines on the B-52. In the end, the USAF decided to not replace the engines. Fuel was cheap at the time, and they have a large surplus of TF-33 engines from the KC-135E fleet. For a while, when the JP-8 was massively expensive, it was thought of again, but budget reasons nixed it. Seems saving money in the long run, improving on station time, and increasing payload aren't good enough reasons to make it happen. At this point, this the Air Force throwing money at the B-21 project, it'll probably never happen.