F-15X: USAF Seems Interested

wonder if they are gonna contract then for the remaining F-15Es and the new F-15X engines so they are common, but at that point the 229 has an advantage unless they want to throw GE a bone with super hornet production winding down and them losing the JSF engine.

IIRC, the SASC version of the NDAA is prohibiting divestment of the F-15C anytime soon.
And the SASC version tends to win out in reconciliation.

Apparently, this $100M contract for the GE-129 is just for Lot 1 of the F-15EX. Competition will occur for follow-on production lots (if any)

https://www.janes.com/defence-news/news ... ompetition

What will be interesting is that since the F110 got rested and cleared for the F-15, most export F-15s and all the truly advanced ones have been powered by the F110. One has to wonder if certifying the F100 on the EX, which is a derivative of those, will really take as long as has been said . There's also the interoperability issue. Unlike the F135/136, the F100 and F110 are not designed to be interchangeable. A fighter with the common engine bay can accept either one, but connections are different, tools are different, procedures are different, testing is different. Realistically once you put either model in, you stay with it. although there have been a few exceptions. The types don't get mixed in the squadrons, the support issues make that cumbersome.

We're only talking 144 airframes here, not thousands like the F-16 or (although it didn't happen) the F-35.

There's also the interoperability issue. Unlike the F135/136, the F100 and F110 are not designed to be interchangeable. A fighter with the common engine bay can accept either one, but connections are different, tools are different, procedures are different, testing is different. Realistically once you put either model in, you stay with it. although there have been a few exceptions.

They can both physically fit into the same confines but that's about all the interchangeably the F135 and F136 were
required to have by spec. Practically everything else was different.

The F-15E had a common engine bay that could accept the -220, -229, and the F110. The USAF did a service evaluation of the F110 ( I believe it was the -100 version) in the late 90s with 2 F-15s at Nellis AFB. Had lots of problems with the nozzle external flaps, same as the F100s that have them removed. Flow turbulence beats the crap out of the nozzles on the F-15

The -229 was designed to fit anywhere the -100/-200/-220 would fit. It would easily go into the F-15C with the only modification to the engine to incorporate ejector cooling for the DEEC, instead of the tank cooling system used on the F-15E and F-16. There may be airframe engine mount beef up needed for the 300-400 lbs extra weight, and weight & balance is always an issue. There is no way that any version of the F110 would fit in the F-15C without complete remanufacture of the aft aircraft structure.

So we appease corporate interests and go one F100 and one F110 per aircraft

So we appease corporate interests and go one F100 and one F110 per aircraft

The Air Force is legally required to compete the engines unless they can show the cost of competition is greater than
the anticipated savings. They can't show this.

So we appease corporate interests and go one F100 and one F110 per aircraft

The Air Force is legally required to compete the engines unless they can show the cost of competition is greater than
the anticipated savings. They can't show this.

Couldn't the USAF just show the gov. drones the same info everybody else used when selecting the F110 over the F100 and call it good?

So we appease corporate interests and go one F100 and one F110 per aircraft

The Air Force is legally required to compete the engines unless they can show the cost of competition is greater than
the anticipated savings. They can't show this.

Couldn't the USAF just show the gov. drones the same info everybody else used when selecting the F110 over the F100 and call it good?

I suspect a lot of that was just the incredibly tight GE/Boeing relationship.
IIRC, there are no Pratt engines on anything new build these days at Boeing (commercial and defense)
aside from the KC-46.

And it's much easier for GE to meet the offset* requirements for foreign sales since they were
far more diversified than Pratt.

*My favorite offset story: Saab getting Electrolux to build a refrigerator factory in Hungary to satisfy the Gripen offsets

wonder if they are gonna contract then for the remaining F-15Es and the new F-15X engines so they are common, but at that point the 229 has an advantage unless they want to throw GE a bone with super hornet production winding down and them losing the JSF engine.

This is peripheral to the F=15EX discussion, but I want to address something that keeps popping up over the years...

GE did not "lose" the competition for the JSF engine because there was no competition for the JSF engine. What happened was that when the X-32 and X-35 were being designed, the contractors were free to choose whatever engine they wanted to power their experimental demonstrators. There were really only two possibilities, the F-119 and the YF120. Given the former was actually in production, by far the safer choice was clearly it.

For the production JSF (F-35), the Program Office plan envisioned two engines. For the first few LRIP lots the F-35 would be powered exclusively by the F135. This was because, being a derivative of the F119, it could be ready sooner than what GE could offer and potentially represented lower risk to the schedule early in the program. The Gov't would also partially fund development of a second engine, which became the F136. After the first few lots, with the GE engine developed, then there would be a competition between the two engines for each lot. This was always the plan, it was what the Program Office and the Services wanted, which they repeatedly stated.

Like I said, for a number of good reasons Pratt developed a derivative of the F119; available sooner, perceived lower risk to the schedule. Originally GE was going to develop a derivative of the YF120. They soon decided, though, that wouldn't give them a strong enough competitive advantage to overcome Pratt's lead. So they decided to develop an engine optimized for the F-35 using technology that had matured since the YF119 and YF120s were designed. They felt they would be able to give more capability this way in return for their later entry into production. One of the reasons the F-35's intakes were enlarged was anticipation of the GE engine that flowed more air.

One thing the Program Office did was that they moved a step beyond the F100/F110 situation, which was that later F-15s and -16s could accept either engine. But because procedures tools, maintenance and operations of the two engines were different, once a plane got either of the engines it stayed with it, and you'd never mix both engines in the same squadron. The F135 and 136 had to use the same tools, be mounted the same way, have the same tests and maintenance, handled the same way, inspected the same way (there was one inspection port on the F136 that was slightly different from where it was located on the F135), even use the same shipping container. There would be no difference in how the engines would be handled at the field or intermediate levels, although there might be a performance difference so you might see a/c with different engines in the same Wing or squadron.

Unfortunately the F136 was terminated not too long before it was scheduled to first fly in an F-35. There were two main reasons. First, while development costs were occurring right now, the benefits from competition wouldn't fully materialize until further down the pike, and the long view is not something Congress and certain parts of DoD are very good at, even when to contractors said they were willing to fund the gov't's portion to finish bringing the engine up to certification. Second was a very well run lobbying program.

It's all moot now, most of the F136 info isn't available any more. I only brought it up because whatever else might be going on, losing the JSF competition isn't a reason USAF wanted to sole source the F-15EX engine. it's more the fact that the F110 is already certified on the advanced F-15E derivatives abroad and that it keeps the program moving at a more rapid clip.

So we appease corporate interests and go one F100 and one F110 per aircraft

The Air Force is legally required to compete the engines unless they can show the cost of competition is greater than
the anticipated savings. They can't show this.

I'm not sure they want to try. They've gotten badly burned in years past by screwing up competitions and they could be so skittish that they just decided to go along rather than push back and potentially risk the whole program which is by no means a sure thing.

Well in any case, it sounds like the F-35 wound up with a great engine. I've heard pilots, maintainers and other rave about it at airshows. Even met some men who built it/build it. They've really proud of what they've developed.

And when bigger, more powerful and more efficient motors get here... going to give the F-35 truly scary capabilities. Yes, it has plenty of thrust now... but is going to have a lot more in the future and with it, even greater "smash" as they say.

The F-35C I think, will benefit most..

So we appease corporate interests and go one F100 and one F110 per aircraft

The Air Force is legally required to compete the engines unless they can show the cost of competition is greater than
the anticipated savings. They can't show this.

I'm not sure they want to try. They've gotten badly burned in years past by screwing up competitions and they could be so skittish that they just decided to go along rather than push back and potentially risk the whole program which is by no means a sure thing.

The burden of proof is legally on the service to show that they cannot achieve savings greater than
the cost of competition which in this case will be very small and (probably) borne by P&W.

There's no evidence in the last decade to suggest that the Air Force GAO protest sustain rate (post-award) is any
higher than any other service. Not to say there haven't been cases where they've screwed up (3DELRR) but those
were honest mistakes that fell in the minutia of an extremely complex program.

The above F136 analysis is both long winded and wrong. The engine was extremely immature and only about 5%
through its development cycle requiring (conservatively) another $3 - 4 billion in funding.

It's was very difficult for anyone to show that that amount could be recouped through competition
esp. given the costs of sustaining a mixed engine fleet and in the face two services (the Navy and Marines) who
did not want a second engine for obvious shipboard reasons.

The Air Force is legally required to compete the engines unless they can show the cost of competition is greater than
the anticipated savings. They can't show this

The burden of proof is legally on the service to show that they cannot achieve savings greater than
the cost of competition which in this case will be very small and (probably) borne by P&W.

There's no evidence in the last decade to suggest that the Air Force GAO protest sustain rate (post-award) is any
higher than any other service. Not to say there haven't been cases where they've screwed up (3DELRR) but those
were honest mistakes that fell in the minutia of an extremely complex program.

The above F136 analysis is both long winded and wrong. The engine was extremely immature and only about 5%
through its development cycle requiring (conservatively) another $3 - 4 billion in funding.

It's was very difficult for anyone to show that that amount could be recouped through competition
esp. given the costs of sustaining a mixed engine fleet and in the face two services (the Navy and Marines) who
did not want a second engine for obvious shipboard reasons.

As far as AF protest sustain rate goes, AF had a series of very high profile acquisition problems (and there is a long memory for this kind of thing) which included people going to jail, which is well beyond the scope of honest mistakes. They really don't want to get involved in another controversy. Regarding competition costs, nothing in DoD is "very small". Just the competition itself is going to cost scads of millions of $$, on a program that maxes out at a potential 144 airframes (less the Lot 1 birds who will get F110)s. P&W can not legally pay the gov't's costs for the competition. Even if they could, they'd just get it back in their pricing, which would up the cost of their engine, which would give an advantage to GE. Plus, if they did try and cover the gov't's costs, that would taint the competition, whenever (if) they won a particular lot buy.

Not wishing to reopen the F135/F136 issue because it's moot at this point. However, a few counter points. The F136 was well beyond 5%. At the time of cancellation, there were more than 1,200 hours on the engine and GE/Rolls said the development was 80% complete. DoD did not contest this. Their estimate for completion was $1.9-2.6 billion, DoD did not contest this either. In fact, the F136 program had won awards for how well it was managed and controlling costs. Remember also that the F136 was less than a year away from first flight in an F-35, and GE/Rolls offered to fund the engine out of their own pocket for the rest of the money to get to that point.

Overall cost savings was only part of the rationale for the two engines in the Alternate Fighter Engine program. There was also the belief that with two contractors both companies would need to provide their best or lose orders to the other guys, whereas with only one supplier you were kind of at their mercy. We saw both of these benefits in the AFE program, which is why there was a push for an alternate engine option on the JSF program. There is also the concern that said competition would delay the whole program, since P&W's offering would have to be tested and certified on the advanced F-15 versions that use the F110.

There is nothing to suggest USN/USMC leadership did not want the 2nd engine option, and lots of indicators that they did. The F-135/136 situation is not like the F100/F110. To quote from my "long winded and wrong" analysis,

"The F135 and 136 had to use the same tools, be mounted the same way, have the same tests and maintenance, handled the same way, inspected the same way (there was one inspection port on the F136 that was slightly different from where it was located on the F135), even use the same shipping container. There would be no difference in how the engines would be handled at the field or intermediate levels, although there might be a performance difference so you might see a/c with different engines in the same Wing or squadron".

This was an absolute requirement. If GE couldn't demonstrate this their engine would not be eligible for purchase. If there was any performance difference, say if the F136 could produce more thrust, within a squadron that would be controlled via the software onboard the F-35.

It's interesting that you appear to favor competing for a program of <144 aircraft which would have to spread the cost of competing over a small production run and have the logistics issues you mention but not for a program of thousands of aircraft which wouldn't have those issues.

Like I said, though, the F135/136 issue is moot and not a factor for the F-15EX.

Saving $2-4 billion to put multiples of that in jeopardy was clearly a political decision.