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Re: USAF Considering New Build F-15X

Posted: Tue Jan 14, 2020 8:47 pm
by JayinKitsap
In an opinion piece at RCD a retired Col writes how important to order the F-15ex, he has valid points but it smacks of a Loren Thompson article where contributors to his site asked him to write, basically PR not news.

https://www.realcleardefense.com/articl ... 14972.html


I agree on the big importance of diversity, why I do like getting the F-15ex, but only if we keep going full throttle on acquiring F-35's , we should at this stage have hundreds more F-35's in service but for the program delays.

Re: USAF Considering New Build F-15X

Posted: Tue Jan 14, 2020 10:12 pm
by Ozair
JayinKitsap wrote:
In an opinion piece at RCD a retired Col writes how important to order the F-15ex, he has valid points but it smacks of a Loren Thompson article where contributors to his site asked him to write, basically PR not news.

https://www.realcleardefense.com/articl ... 14972.html


I agree on the big importance of diversity, why I do like getting the F-15ex, but only if we keep going full throttle on acquiring F-35's , we should at this stage have hundreds more F-35's in service but for the program delays.


A couple of problems with the article. He talks about diversity but ignores that the USAF will continue to operate F-15s, in the form of the E, until at least 2040. The USAF will also continue to operate F-16s until at least the mid 2030s and potentially longer. Who knows how long the A-10s will last. Add in the F-22s which aren’t going anywhere and you have all the diversity you need.

The flight hour cost is also wrong in that it is only factoring in the cost of operating the jet on a per hour basis and ignores the costs involved in maintaining a sub fleet of aircraft. The USAF wants economies of scale that come with operating large numbers of a single type and the number is approx. 150+ for that to happen.

An F-15EX carrying 22 A2A missiles is not going to have a very good range nor speed given the drag and number of pylons occupied by that loadout. It is better to consider alternative arrangements for the carriage of additional missiles for 5th gen assets, such as loyal wingmen, than maintain a 4th gen aircraft as a bomb truck in threat environments it likely cannot survive in.

The final issue I have is this continual problem with people claiming the F-35 cannot take hypersonics in its internal weapons bay, and therefore isn’t suited to that weapon/role. The F-35 has external pylons rated to the same weight as the F-15 and is more than capable of hosting larger weapons. The F-35 also has the advantage of having all its fuel internal and therefore not sacrificing range for the carriage of a hypersonic weapon, which the F-15EX would do with a large hypersonic weapon taking the place of the wing drop tanks. The F-35 could also deploy a hypersonic weapon and then follow that up with a stealth configuration into the battlespace using payload held within its internal bomb bay.

Re: USAF Considering New Build F-15X

Posted: Wed Jan 29, 2020 8:23 pm
by Ozair
The acquisition process for the F-15EX has started. We have confirmation now the USAF will use the GE F110-129 on the aircraft in place of the P&W F100 which powers all other USAF F-15 aircraft. That shouldn’t be too much of an issue given the F110 also powers over 85% of the USAF F-16C/D fleet so more than enough knowledge and experience in the wider community. What it may do is increase the transition time for units and perhaps a change in local spares holdings and equipment.

Now the big question is which unit will move to the F-15EX first.

Air Force Starts F-15EX Buying Process

The Air Force has launched the process of buying new F-15EX fighters with dual pre-solicitation notices from the Life Cycle Management Center at Wright-Patterson AFB, Ohio.

The notices, dated Jan. 28, announce USAF’s intention to purchase F-15EX jets from Boeing and F110-129 engines from General Electric Aviation, with both companies as sole source suppliers.

The indefinite delivery/indefinite quantity contracts are labeled as a “refresh to the F-15C/D fleet” as well as to “augment” the F-15C/D fleet with new airplanes. A contract is anticipated in May.

Although Pratt & Whitney also makes an engine that could power the F-15EX, its powerplant is not certified for the airframes the EX model is based on, which Boeing is building for Qatar and Saudi Arabia. The Air Force’s desire to obtain speedy delivery of the jets rules out a test program for the Pratt & Whitney engine, which has not been evaluated with the digital, fly-by-wire F-15EX, an Air Force acquisition official explained. Each F-15EX requires two engines, and USAF will also buy spares, for a package of up to 480 of the powerplants. Some of those may power older F-15s.

The GE F110-129 powers more than half of Air Force F-16s and more than 80 percent of USAF’s F-15E strike aircraft.

This first year of the program, the Air Force plans to buy eight F-15EX fighters, although future plans call for as many as 144 aircraft. Congress approved only two F-15EXs in the fiscal 2020 National Defense Authorization Act, with the proviso that USAF can buy the other six after submitting a report on its acquisition strategy for the program. The eight aircraft, including initial engineering, hardware and software design, integration of subsytems and parts production, would run about $1.1 billion the first year.

...

https://www.airforcemag.com/air-force-s ... g-process/

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 12:01 am
by SuperiorPilotMe
I wish we can start calling it F-15E Block 40 or whatever, EX reeks of Boeing PR speak.

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 2:23 am
by texl1649
F110 vs. F100 in the Eagles in USAF inventory is a bit amusing to happen now finally in the 2020’s vs. the past 40 years. It is a surprising decision but indicative again of the high degree of risk intolerance in procurement today for the USAF.

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 2:40 am
by Ozair
SuperiorPilotMe wrote:
I wish we can start calling it F-15E Block 40 or whatever, EX reeks of Boeing PR speak.

Perhaps we will get an official model number from the USAF at some point. It really feels like with the changes compared to the E that we could easily go to a “G” but that has traditionally been associated with wild weasel aircraft so maybe a “I”, nope that is Israeli so how about “K”, sorry South Korea, “M”, maybe we have arrived at the right one and perhaps fitting to stand for “Maybe” (not Mike) given the on again off again acquisition the aircraft has had to go through.

While I agree EX is very PR it may just stick unless the USAF wants really wants to go to G. I really can’t see them going to M…

texl1649 wrote:
F110 vs. F100 in the Eagles in USAF inventory is a bit amusing to happen now finally in the 2020’s vs. the past 40 years. It is a surprising decision but indicative again of the high degree of risk intolerance in procurement today for the USAF.

Not surprising in the context of the F-15SA, which the EX is based off, is certified with F110s and not F100s so the USAF would have to go through a new test program for the F100. I don’t think they want to waste that time and therefore spending a bit more cash to train the current F100 ANG units to F110 makes more sense.

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 7:40 am
by steman
Ozair wrote:
Perhaps we will get an official model number from the USAF at some point. It really feels like with the changes compared to the E that we could easily go to a “G” but that has traditionally been associated with wild weasel aircraft so maybe a “I”, nope that is Israeli so how about “K”, sorry South Korea, “M”, maybe we have arrived at the right one and perhaps fitting to stand for “Maybe” (not Mike) given the on again off again acquisition the aircraft has had to go through.

While I agree EX is very PR it may just stick unless the USAF wants really wants to go to G. I really can’t see them going to M…




Isn´t F-15F available? It´s the next in line after the -E.
Although I´m sure they´ll go with some boring block number like on the F-16.

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 8:40 am
by Ozair
steman wrote:
Ozair wrote:
Perhaps we will get an official model number from the USAF at some point. It really feels like with the changes compared to the E that we could easily go to a “G” but that has traditionally been associated with wild weasel aircraft so maybe a “I”, nope that is Israeli so how about “K”, sorry South Korea, “M”, maybe we have arrived at the right one and perhaps fitting to stand for “Maybe” (not Mike) given the on again off again acquisition the aircraft has had to go through.

While I agree EX is very PR it may just stick unless the USAF wants really wants to go to G. I really can’t see them going to M…




Isn´t F-15F available? It´s the next in line after the -E.
Although I´m sure they´ll go with some boring block number like on the F-16.

That wouldn't follow the nomenclature of previous versions, noting the E probably should have been called an F anyway because of the two seats. F is possible but as you and superior suggest a block number seems more likely.

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 11:19 am
by texl1649
On the nomenclature, the USAF, or rather perhaps General Dynamics back in the day did coin the F-16XL as a derivative name, in the competition that led to the strike eagle...which eventually led to the F-15EX.

Somewhat ironically, a fully developed version of that might have also been a good missile truck with lot’s of fuel etc. (imagine with conformal tanks etc.) Ah well, Lockheed obviously didn’t want to revive that idea at all (and it wouldn’t have been practical to do so).

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 1:05 pm
by bikerthai
While many of the single letter remains, since this will more or less be the last USAF F-15 buy, it is logical to consider F-15US. Or if our Pres gets a say . . .F-15USA. . . .USB if heaven for bid, they decide in a 2 seat model.

bt

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 3:02 pm
by texl1649
And ironically, the F-16XL did achieve (way too late, in NASA experiments) supercruise...with a single GE F110-129 engine

https://www.avgeekery.com/f-16xl-advanc ... le-better/

Image

NASA and GD combined forces to replace the engine in 848. After receiving a production GE F110-129 engine, 848 eventually did achieve supersonic cruise (supercruise). 848 was modified with research gloves on both wings. The port wing glove was substantially larger. A team from NASA’s Langley Research and Dryden Research Centers, Rockwell International, Boeing, and McDonnell Douglas designed and built the wing glove. 848 was used primarily for supersonic laminar-flow research. Once NASA test programs concluded in 1999, both of these distinctive aircraft went into storage at Edwards AFB. They remain there today.

Re: USAF Considering New Build F-15X

Posted: Thu Jan 30, 2020 9:49 pm
by Ozair
bikerthai wrote:
While many of the single letter remains, since this will more or less be the last USAF F-15 buy, it is logical to consider F-15US. Or if our Pres gets a say . . .F-15USA. . . .USB if heaven for bid, they decide in a 2 seat model.

bt

My expectation was that the whole X fleet would be two seaters but I haven’t seen that confirmed anywhere and a year ago “The Drive” suggested the opposite, that the majority would be single seat aircraft,

Oh, and there are two variants of the F-15X that are being offered by Boeing and will likely be procured. One is dubbed the F-15CX and the other is known as the F-15EX.
The F-15CX will be a single-seat configuration, while the F-15EX will be a two-seater with a fully missionized rear cockpit complete with a wide-area flat panel display, helmet-mounted display, and full flight controls. The F-15EX will cost a couple million dollars more than its single seat stablemate, but they will roll of the St. Louis production line right alongside one another.


https://www.thedrive.com/the-war-zone/2 ... m-per-copy

We could then see the fleet take the suggested CX and EX name but that will have to be agreed by the USAF. My feeling is that will be too close to the original aircraft, doesn't make sense in the respective variants mission capabilities and therefore a new letter is a clearer option.

But please BT never suggest F-15USA/USB again… :?

Re: USAF Considering New Build F-15X

Posted: Sat Feb 01, 2020 5:19 am
by FlyHossD
SuperiorPilotMe wrote:
I wish we can start calling it F-15E Block 40 or whatever, EX reeks of Boeing PR speak.


Well, as long as Boeing doesn't call it the F-15Max, should we really complain?

Re: USAF Considering New Build F-15X

Posted: Sat Feb 01, 2020 1:49 pm
by bikerthai
SuperiorPilotMe wrote:
I wish we can start calling it F-15E Block 40 or whatever, EX reeks of Boeing PR speak.


But sometimes PR can be good. This time, however, the EX is more or less within the Boeing process.

Believe it or not, there is a documented procedure within Boeing on how to number their programs, from satellites to commercial aircraft.

Not sure if they followed procedure with the MAX, but the EX follows the last AF buy, the F-15E. Similar to the 777X. As for "Block 40", that may be a LM thing.

So procedure will dictate that they will drop the X and go with new letter or two. And since the last few variants are two letters, my long shot money is on F-15US.

bt

Re: USAF Considering New Build F-15X

Posted: Tue Feb 11, 2020 10:54 pm
by Ozair
The USAF has budgeted for twelve F-15EX in their 2021 budget proposal and going by the language in the quote below are looking at the aircraft being based on the F-15QA with some USAF only capabilities, which would be EPAWSS, radar etc. The statement does also specifically state the QA two seat so perhaps this is semi confirmation they will acquire only two seat aircraft.

The expected minimum procurement quantity for F-15EX is 144 aircraft (a combination of 2 in RDTE (PE27134F); 6 in F015E0 (Line #3); and 136 in F015EX (Line #4). F-15EX is currently a Middle Tier Acquisition program, not a Major Defense Acquisition Program. Once the program transitions to a Major Defense Acquisition Program and the Acquisition Program Baseline is approved, the total program quantity for F-15EX will be established. All numbers are based on the Air Force Cost Analysis Agency's initial Non-Advocate Cost Assessment and will be refined for major milestones and on an annual basis.

The F-15EX will be based on the 2-seat F-15QA (Qatar) configuration upgraded with USAF-only capabilities, including the Eagle Passive Active Warning and Survivability System (EPAWSS) and the Suite 9.1 Operational Flight Program (OFP) software. With two seats, it will be multirole-capable and operable by one or two aircrew. Many F-15C/Ds are beyond their service life and have SERIOUS structures risks, wire chafing issues, and obsolete parts. Readiness goals are unachievable due to continuous structural inspections, time-consuming repairs, and on-going modernization efforts. The average F-15C/D is 36 years old with over 8,400 flight hours; the oldest F-15C was delivered in 1979. F-15EX logistics, maintenance, and training will heavily leverage the existing F-15 infrastructure.

https://www.saffm.hq.af.mil/Portals/84/ ... 145310-973

Numbers expected over the next five years are the following,
2021 – 12
2022 – 12
2023 – 14
2024 – 19
2025 – 19

Delivery of the 2021 order is expected to start in April 2024 with two arriving every month from April to September. The budget proposal lists 60 remaining for a total to complete of 136 aircraft. This total with the 8 approved last budget reaches to 144.

Bad news is the fly away cost is already above the US$80 million Boeing claimed they could reach, the 2021 order will see a fly away cost of US$87.7 million each with that cost not looking to reduce in subsequent years.

Flyaway - F-15EX Cost Recurring Cost Airframe 73.600
Engines (2) 11.200
AME 1.100
ECO 1.800
Subtotal: Recurring Cost for 12 airframes is 1,052.400



Meanwhile it looks like Valerie trolled out a canned article and didn’t do any research on costs and delivery schedule… It also appears that the USAF and Boeing have still not signed a contract for the initial two + six jets ordered.

F-15EX is a boon to Boeing, but it might not break the international fighter market

Boeing’s F-15 program is getting a second life as the U.S. Air Force begins buying new aircraft, but it remains to be seen whether the company will be able to ring in international sales of the F-15EX model in a competitive fighter market.
In December, Congress approved a $985 million request by the Air Force to buy the first eight F-15EX aircraft, with two to be delivered by the end of the year. The Air Force issued a pre-solicitation Jan. 23, declaring its intent to sole source the F-15EX from Boeing.
In a statement to Defense News, Boeing F-15 program manager Prat Kumar expressed concern about the pace of contract negotiations, but sounded optimistic about potential international sales.
“Needless to say, we need to be on contract to deliver these jets. We do not fully control the timing of when we get on contract, but we’re doing everything within our control to deliver F-15EX jets before the end of the year,” he said.



https://www.defensenews.com/digital-sho ... er-market/

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 12:22 am
by 744SPX
I get the feeling Boeing is pushing the EX over the CX as it will be cheaper for them (production commonality) to keep the E models twin seating arrangement. (when is the last time they produced a single seat F-15?) They will probably try and push it on foreign buyers as well. For the C model replacement, the twin seat cockpit adds completely unnecessary weight and drag, even if only a little. I had a bad feeling the CX would never see the light of day, and IMHO its looking like that will be the case.

Personally, I was never a fan of the B/D/E model's twin seat cockpit canopy aesthetics. Kinda ruined the A and C models good lines. At least the 15 is getting its turkey feathers back with the F-110 engines.

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 12:50 am
by texl1649
Something tells me these F110 powered F-15’s will be the final iteration of the breed in around 2050. Or later...

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 1:09 am
by Ozair
744SPX wrote:
I get the feeling Boeing is pushing the EX over the CX as it will be cheaper for them (production commonality) to keep the E models twin seating arrangement. (when is the last time they produced a single seat F-15?) They will probably try and push it on foreign buyers as well. For the C model replacement, the twin seat cockpit adds completely unnecessary weight and drag, even if only a little. I had a bad feeling the CX would never see the light of day, and IMHO its looking like that will be the case.

Agree 100%. I think the EX provides generally better flexibility going forward for what is either the same cost or as you suggest likely less cost than restarting single seat production. There is no reason it cannot be flown single seat and the second seat reduces fuel by what is really an insignificant amount. A two seat F-15EX would also make an effective drone/loyal wingman controller.


texl1649 wrote:
Something tells me these F110 powered F-15’s will be the final iteration of the breed in around 2050. Or later...

Certainly possible although I have seen the suggestion/theory on several forums that the USAF is using the F-15EX as a ploy to get more PCA. By eliminating the F-15C/D from the orbat with the F-35 there would be a weaker justification to replace those F-35 units with PCA. Compared to the PCA being built in sufficient numbers to replace F-22 and F-15E/EX that are present in the orbat in late 2030s.

A theory which I don’t subscribe to as I don’t think anyone in the Pentagon is planning that far ahead given future budgetary uncertainty but interesting nonetheless.

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 11:31 am
by texl1649
FG is reporting Boeing may also offer F-15 now to India, in a related matter. They’re already offering the super hornet, of course.

https://www.flightglobal.com/singapore- ... K0.twitter

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 1:51 pm
by bikerthai
Ozair wrote:
Agree 100%. I think the EX provides generally better flexibility going forward for what is either the same cost or as you suggest likely less cost than restarting single seat production.


Actually this cost question is a little more complex.

Having to design the single seat variant from the QA would cost a little more in terms of non-recuring Engineering hours. But from a recurring production stand point, without the plumbing and wiring and cost of the second seat, the cost per frame would be lower.

We have always kicked around the phrase that Engineering hours are cheap when compared to manufacturing hours. Specially when the production quantity gets into the hundreds.

I wonder if that is the reason why the price went up . . . Because of the second seat?

bt

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 2:27 pm
by 744SPX
Can't recall... does the second seat affect fuel capacity?

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 2:42 pm
by texl1649
The second driver might be useful in a 'loyal wingman' supported mission.

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 3:04 pm
by bikerthai
744SPX wrote:
Can't recall... does the second seat affect fuel capacity?


Looks like the bay for the second seat would have been used for electronics - similar to the "C".

http://aviazioneaereimilitari.altervist ... -eagle.jpg

bt

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 9:32 pm
by Ozair
bikerthai wrote:
744SPX wrote:
Can't recall... does the second seat affect fuel capacity?


Looks like the bay for the second seat would have been used for electronics - similar to the "C".

http://aviazioneaereimilitari.altervist ... -eagle.jpg

bt

This cut away of the F-15SE shows the fuel tank arrangement and IMO shows the tank cuts off earlier than it would on a A/C model. That would be standard for the second seat on an F-16 and F-18 noting the Eagle is a significantly bigger aircraft and may not have that limitation.

Image

bikerthai wrote:

Actually this cost question is a little more complex.

Having to design the single seat variant from the QA would cost a little more in terms of non-recuring Engineering hours. But from a recurring production stand point, without the plumbing and wiring and cost of the second seat, the cost per frame would be lower.

We have always kicked around the phrase that Engineering hours are cheap when compared to manufacturing hours. Specially when the production quantity gets into the hundreds.

It really isn’t more complex. When was the last time Boeing manufactured a single seat Eagle? The parts that made the single seat haven’t been manufactured in a long time while the two seat variant is in production and has active parts manufacture. I have no doubt it would be cheaper to maintain two seat production than try and to redesign a single seat aircraft in there. Even just restarting canopy construction for a single seat would likely cost more than it is worth.

bikerthai wrote:

I wonder if that is the reason why the price went up . . . Because of the second seat?

bt

An ejection seat is approx 200-300K. With a few additional cockpit screens and instruments etc it isn’t going to explain to 10+ million additional cost. It is clear the additional cost compared to Boeings (which most people agreed was unlikely) $80 million claim has nothing to do with the USAF likely using two seats for the EX fleet.

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 10:46 pm
by bikerthai
The cut-away shows he refeuling receptacle on the left wing. If that is the same for all variant, then it does not make sense to place a tank forward of that. The complexity of running fuel lines forward would make it not worth while.

The cost of the extra seat is not the only part of the calculation. You also have the cost of installing the plumbing for oxygen, and display for the additional pilot etc.

If that they were going to have the provisions anyway, then I would say that the different cost of the extra seat would not make it to 4 mil. But if the full cockpit was not in the original estimate, the I can see how you can get there from here.

bt

Re: USAF Considering New Build F-15X

Posted: Wed Feb 12, 2020 11:58 pm
by Ozair
bikerthai wrote:
The cut-away shows he refeuling receptacle on the left wing. If that is the same for all variant, then it does not make sense to place a tank forward of that. The complexity of running fuel lines forward would make it not worth while.

That entire tank is forward of the receptacle. You can see the red fuel line coming out of the receptacle and past the back of the tank.


bikerthai wrote:
The cost of the extra seat is not the only part of the calculation. You also have the cost of installing the plumbing for oxygen, and display for the additional pilot etc.

Yes and I mentioned that already. This all already exists though so there is no engineering work to do done, it really isn't that much more cost wise.

bikerthai wrote:
If that they were going to have the provisions anyway, then I would say that the different cost of the extra seat would not make it to 4 mil. But if the full cockpit was not in the original estimate, the I can see how you can get there from here.

bt


The Boeing image of the F-15EX clearly shows a two seat aircraft, as do all the graphics on the Boeing Website for both the F-15EX and the F-15 Advanced.

Re: USAF Considering New Build F-15X

Posted: Thu Feb 13, 2020 1:13 am
by bikerthai
Ozair wrote:
Yes and I mentioned that already. This all already exists though so there is no engineering work to do done, it really isn't that much more cost wise.


I do not disagree. It would cost engineering hours to remove the system for the second seat. But the per frame manufacturing cost would be lower.

bt

Re: USAF Considering New Build F-15X

Posted: Thu Feb 13, 2020 10:14 am
by Ozair
bikerthai wrote:
Ozair wrote:
Yes and I mentioned that already. This all already exists though so there is no engineering work to do done, it really isn't that much more cost wise.


I do not disagree. It would cost engineering hours to remove the system for the second seat. But the per frame manufacturing cost would be lower.

bt

If we knew the cost difference between an F-18E and F model it would give an excellent metric for us to grade a single seat versus two seat F-15 manufacturing cost. Unfortunately the FMS cases don't break down the individual costs and neither does the SH SAR, https://www.globalsecurity.org/military ... c-2010.pdf

Re: USAF Considering New Build F-15X

Posted: Sun Feb 16, 2020 10:49 pm
by Ozair
Be interesting to see if this goes anywhere. It will possibly delay the contract award to GE and if it is approved would likely require the USAF to bid the contract. I’d expect GE to still win given the F110 is already integrated on the F-15QA which the EX is based off but P&W likely deserves the opportunity to at least try.

Pratt & Whitney protests F-15EX engine procurement

Pratt & Whitney is protesting the US Air Force's (USAF's) intention to sole source General Electric (GE) F110 engines for its Boeing F-15EX Advanced Eagle fighter aircraft, Jane's has learned.

The bid protest was filed on 7 February with the US Government Accountability Office (GAO). A decision is due no later than 18 May.

The USAF on 23 January announced its intent to sole source the GE F110. The service plans to acquire as many as 480 F110 engines, engine monitoring system computers, integrated logistics support, support equipment, and tooling.

...

https://www.janes.com/article/94340/pra ... rocurement

All US F-15s are P&W powered so keeping to the F100, while possibly taking longer in development to integrate the engine into the QA, may save some costs on ground infrastructure and maintenance/spares at existing ANG F-15C/D bases.