If the Stratofortress is going to serve as long as expected, a new power plant will probably pay for itself. Reducing from eight to four engines means fewer moving parts and fewer maintenance hours. New engines mean parts and services are readily available and improvised repairs would be a thing of the past. The fuel economy of modern engines would significantly extend the B-52's already enormous unrefueled range and reduce stress on the equally aged tanker fleet. The question is will the Air Force want to put the cash up front to pay for new engines.
Several years ago a plan was floated to lease new engines, common practice among commercial airlines. Congress, however, required the Air Force to budget enough money to replace the leased engines, largely defeating the purpose of leasing instead of buying. - -Andy Wagner
Rumors are emerging once again about replacing the B-52 fleet's aging TF33 engines with something modern. The TF33s, long-time workhorses on the B-52, the C-141 transport, and the KC-135 tanker-and its variations-have been reworked and rebuilt to the point that many are beyond even their useful life for reconstruction. A very successful program is underway for early KC-135Es that includes replacing the older engines with the popular CFM56 as part of the new KC-135R standard. The CFM56 serves on most 737 airliners and is known for high reliability and maintainability as well as great fuel economy. Unfortunately, these large diameter high-bypass engines would not easily fit in the B-52s dual-engine underwing pods. A more likely choice would be to replace eight small engines with four larger ones. The Pratt & Whitney PW2000 (C-17 transport) or GE CF6 (747) could be leading candidates, based on their thrust. There is little doubt the engine would be an off-the-shelf model.