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10/20/2017 1:01:18 AM
9/22/2017 12:11:25 AM
Posted: 8/27/2005 9:10:25 AM EDT
[Last Edit: 8/27/2005 9:10:48 AM EDT by ZitiForBreakfast]

Why not CFM's?
Link Posted: 8/27/2005 9:12:04 AM EDT
Link Posted: 8/27/2005 9:12:27 AM EDT
What the hell are you asking?
Link Posted: 8/27/2005 9:14:02 AM EDT
[Last Edit: 8/27/2005 9:17:30 AM EDT by JustinOK34]
Assuming you're wondering why they don't have CFM motors?

Beats me. I don't build airplanes.

Edit: What do they use? TF33? By Pratt & Whitney?

Edit: They do use TF33s. There was talk of upgrading to some Rolls Royce.
www.answers.com/main/ntquery?method=4&dsid=2222&dekey=B-52+Stratofortress&gwp=8&curtab=2222_1&linktext=%3CSPAN%20class%3Dhl0%3EB-52%3C%2FSPAN%3E%20Stratofortress
Link Posted: 8/27/2005 9:19:16 AM EDT
It would cost way to much to retrofit CFM's on a B52. Assuming the A/C would loose four motors the whole pylon would have to be re-engeniered. Some 707 airframe have CFM motors on them. I think the military would rather have a upgraded Avionics/weapons platform than an Engine upgrade
Link Posted: 8/27/2005 9:27:44 AM EDT
Been studied to death.

At the time (late 80's early 90's) there were enough complete TF33 engines and spares left to keep the fleet flying for another 12-17 years.

Boeing submitted a proposal to re-engine them with Rolls Royce engines, the RB.211-535E4-B turbofan.

It's not just a straight forward engine swap, the pylons would need to be modified/remanufactured, the wings would need to be strengthened and the flight procedures would need to be modified.

I think that if the USAF wants to end the life of the B-52 at 2025 it is going to need to renegine a "few" of them.


An unsolicited proposal for reengining 94 aircraft in the B-52 fleet was submitted to the Air Force by Boeing North American, Inc. in June 1996.

Boeing proposed modernizing the B-52 fleet by replacing the current TF-33 engines with a commercial engine through a long-term leasing agreement, and providing fixed-cost, privatized maintenance based on the number of hours flown each year.

Boeing's proposal included modernizing the B-52 fleet by replacing the TF-33 engines with the Allison/Rolls commercial RB-211 engine through a long-term leasing agreement and providing a fixed-cost, privatized maintenance concept through a "power-by-the-hour" arrangement.

Boeing initially projected reengining cost savings of about $6 billion, but later revised the projected savings to $4.7 billion to reengine 71 B-52s.

An Air Force team formed to study Boeing's proposal analyzed the lease and purchase alternatives and concluded that both options are cost prohibitive compared to maintaining the existing TF-33 engines.

The General Accounting Office estimated that Boeing's unsolicited proposal to reengine the B-52 fleet would cost the Air Force approximately $1.3 billion rather than save approximately $4.7 billion as Boeing projected.



Link Posted: 8/27/2005 1:13:26 PM EDT
Not to hijack,but back in the early 80s,there was also talk of refiting the rest of the DC-8 fleet with CFMs(the DC-8 airframe is very robust,damned near unlimited)however,the cost was prohibitive,and as a result,only 110 were done. Falling fuel prices and cheap hush-kits were the major reason.(would loved to have seen a -50 series done!)
Link Posted: 8/27/2005 1:31:59 PM EDT
[Last Edit: 8/27/2005 1:32:29 PM EDT by KA3B]

Originally Posted By MattyMattel:
Not to hijack,but back in the early 80s,there was also talk of refiting the rest of the DC-8 fleet with CFMs(the DC-8 airframe is very robust,damned near unlimited)however,the cost was prohibitive,and as a result,only 110 were done. Falling fuel prices and cheap hush-kits were the major reason.(would loved to have seen a -50 series done!)




I LOVE the Super-8 with CFM56's!


I did manage to get one flight on this Navy EC-24 (DC-8-54F).



No CFM's though.
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