Boeing B-52J / B-52 Re-Engining

[Scott Kenny]

"smoke on the bomber / and fire in the sky " LMAO

"We burned down the Kremlin house, it died with an awful flash..."

I did not realise that the early turbojet B-52 also used water injection? Was that to increase thrust?

Yes. Cooler air into the turbines which allows more fuel to be burned, more mass flow from the fuel and the water. It's an old Jet trick, works well but causes incomplete combustion = lots of smoke.

 

[BlackBat242]

The J75 in the F-105 had it too.

As well as a number of other aircraft with engines designed in the late 1940s - early 1950s.

Just a quick glance finds:

J33 (RF-80/F-80, F9F, F-94)
J42 (F9F)
J47 (B-45A/C & B-47E)
J48 (F9F)

 

[Scott Kenny]

As well as a number of other aircraft with engines designed in the late 1940s - early 1950s.

Just a quick glance finds:

J33 (RF-80/F-80, F9F, F-94)
J42 (F9F)
J47 (B-45A/C & B-47E)
J48 (F9F)

Even the Pegasus engine in Harriers used water injection.

 

[Forest Green]

https://twitter.com/x/status/1867630415671894250

 

[NMaude]

So how long before the first flight of a YB-52J?

 

[MadRat]

Sonuva... smokeless B-52's!?

 

[Scott Kenny]

Sonuva... smokeless B-52's!?

It's just not right...

 

[FighterJock]

But potential enemy's won't see the B-52Js coming, I think that was the whole point of the new engines Scott Kenny.

 

[BlackBat242]

But potential enemy's won't see the B-52Js coming, I think that was the whole point of the new engines Scott Kenny.

The point of the new engines is that the TF33s were ancient, no parts were being made any more, and they are close to running out of the spare parts cache* they got when the C-141s (which also used TF33s) were retired in favor of the C-17s.

This gets them new engines with far lower maintenance needs (lower failure rate and fewer parts per engine), an active production line for both engines and parts, and lower fuel use for the same thrust.

In the 1990s - early 2000s the USAF was wanting to replace the engines for the same reasons, but the retirement of the C-141s gave the B-52H fleet a bunch of new parts etc. The two models of the engines (-3 for B-52H and -7 or -7A for the C-141) were different in some details, but many parts were interchangeable, thus easing the strain on the supply situation.

 

[FighterJock]

Thanks BlackBat242, I am surprised that the USAF stuck with the TF33s for so long. I know that they tried to get them replaced with newer engines back in the early 2000s but that program fell through for some reason that I have forgotten.

 

[Josh_TN]

Thanks BlackBat242, I am surprised that the USAF stuck with the TF33s for so long. I know that they tried to get them replaced with newer engines back in the early 2000s but that program fell through for some reason that I have forgotten.

The problem was always up front cost when so many engines and parts were available combined with the complications of a four engine conversion (almost impossible for asymmetric thrust in an engine out scenario). As @BlackBat242 notes, exhaustion of the TF33 supply was the motivation.