F-15X: USAF Seems Interested

The fact sheet for the 366 CMS is very vague on what level of support they provide for the -129 engines.

I know they have a full intermediate shop and test cell for their F100 engines. When someone with direct knowledge of their F110-129 intermediate maintenance capabilities chimes in, I will believe it.

Does knocking on the doors of the engine shop at building 1339 and asking them what they do inside count? I understand they brought in extra tooling equipment specific to the maintenance of the SG GE engines.

Pretty strongly worded opinion piece against F-15X by retired AF gen.

https://www.defensenews.com/opinion/com ... -mistakes/

Pretty strongly worded opinion piece against F-15X by retired AF gen.

https://www.defensenews.com/opinion/com ... -mistakes/

The comments...

Hardly, surprising..........

(Ret) Gen. John D.W. Corley is former F-15A/B/C/D Pilot.....As a matter of fact he was an F-15 Instructor Pilot and Aggressor Pilot. He was also the Deputy Commander, later, Commander, 33rd Operations Group, Eglin AFB, Fla. (F-15 Wing)


Speaks volumes.....

That would be like Snort or Hoser (RIP) writing an argument against new Tomcats.

The Case for Fifth-Generation and NGAD Airpower

By Lt. Gen. David A. Deptula, USAF (Ret.), Maj. Gen. Lawrence A.
Stutzriem, USAF (Ret.), and Heather R. Penney

QUOTE:

With only 186 F-22s and about 200 F-35s to complement
its aging fourth-generation fighters, the Air Force has too
few fighters to defend the United States in a modern security
environment including a potential North Korean conflict
occurring simultaneously with a requirement to check Russian
revanchist actions in Europe, or Chinese aggression in
East Asia.
Yet instead of increasing the buy rate for more low-observable
F-35s to support the goals of the new defense strategy,
the Department of Defense (DOD) fiscal 2020 budget request
seeks to purchase eight F-15EX fighters—aircraft based on a
design that dates back to the late 1960s. Even as new-build
with upgraded capabilities, these fourth-generation F-15EXs
will lack key attributes necessary to survive and operate in
the priority advanced threat environments identified in the
National Defense Strategy. Low observability, commonly
known as stealth, and sensor fusion are not bolt-on capabilities
and cannot be retrofitted or modified: They must be
designed into an aircraft from Day 1.
Air superiority is a prerequisite to joint operations. Without
Air Force contributions, other military services’ capabilities
cannot be realized. Ships, ground forces, space and cyber
facilities, logistics nodes, and support aircraft are all exceedingly
vulnerable to attack from modern weapons. Failure to
modernize our air forces with relevant, capable, and survivable
aircraft will result in crippling losses in a conflict with
a rival such as China or Russia. Recapitalizing the Air Force
fighter force with fifth-generation aircraft is fundamental to
fielding viable US military power around the globe.
Given those stakes, it is crucial to prioritize the production
of fifth-generation fighter aircraft. The US should increase
F-35 procurement rates and accelerate investment in the
Next-Generation Air Dominance (NGAD) program to make
up for its undersized F-22 fleet. Today’s fighter force consists
of 82 percent fourth-generation and only 18 percent
fifth-generation aircraft. Reversing that balance is the only
way to ensure America’s sons and daughters strap into aircraft
that can successfully execute their missions against the
world’s most challenging threats—and return home safely.

Page 46 - 56

http://www.airforcemag.com/MagazineArch ... 0Issue.pdf

Does knocking on the doors of the engine shop at building 1339 and asking them what they do inside count? I understand they brought in extra tooling equipment specific to the maintenance of the SG GE engines.

It took me a few days to reach out to my contacts to "knock on the doors of the engine shop" at the 366th at Mt. Home.

I can confirm that the F-15SG F110-129 engines are maintained in a fully functional intermediate maintenance operation at Mt. Home. However, this maintenance is performed by Singapore AF personnel, using Singapore owned support equipment, in a separate area of the 366th engine shop.

This does not change my original point - the USAF currently has little or no F110 intermediate maintenance capability at any F-15C/D or F-15E base. If the F-15EX is procured by the USAF with the F110 engines, they will also have to purchase the necessary support equipment, train personnel, and ensure they have the shop and test cell facilities for those engines at that F-15 base.

Yes, it can be done, but it will be expensive to establish this new support capability at whatever USAF F-15 base they are located at.

And don't be fooled by the fact support equipment is less than 10% of the value of the aircraft or engine - I have seen major battles fought in the AF over the cost of support equipment

Of course, if they are equipped with the F100-PW-229, the job is easier. Both Nellis and Mt Home engine shops already have dual -220 / -229 capability, and the support equipment and training are about 80% common for these engines.

Of course, if they are equipped with the F100-PW-229, the job is easier.

It would be easier for Mx, surely. Mission planning? Maybe not. Looking at the F-16 application the F110-129 offers better supersonic acceleration and, much more importantly, faster cruise speeds at higher cruise altitudes using less fuel per mile when compared to the F100-229.

4 page PDF of entire article (only excerpted here) attached below. Combat Aircraft Magazine October 2019 Vol20 no10.

NEW EAGLES WILL NOT IMPACT F-35
Oct 2019 Combat Aircraft Mag'n Jamie Hunter

“Discussing the plan to buy new F-15EX Eagles from Boeing, US Air Force chief of staff Gen Dave Goldfein made it clear when talking to Combat Aircraft this summer that the F-35 remains untouchable.

THE US AIR Force is moving forward with plans to purchase new F-15EX Eagles from Boeing. In March 2019, the Fiscal Year 2020 defense budget included $1.05 billion for eight aircraft, which included frontloaded production line set-up costs for the US aircraft. The DoD allocated $7.86 billion over the five-year future spending plan to acquire as many as 80 F-15EXs, which will be used to directly replace the oldest F-15Cs.

In addition to the first eight jets, which will be delivered by the end of 2022, $1.65 billion was earmarked for 18 more Eagles in 2021, and the same number through each year to 2024. Ultimately, the USAF could procure as many as 144. USAF chief of staff Gen Dave Goldfein told the Senate Appropriations Committee on March 13, ‘We used the best cost estimates that we had and looked at the various options. The most affordable options, as long as we keep the F-35 on track with our program of record, was to look at an F-15 variant to replace the F-15C.’

Speaking to Combat Aircraft in London this July, Goldfein said of the new F-15EX procurement, ‘Let me tell you what it is not. It’s not in any way, shape or form in competition with the F-35. The F-15EX, or any fourth-generation airplane, isn’t an F-35 — it’s not even close and it never will be. The difference between fourth and fifth-generation is not the platform, it’s the fusion of information that allows the pilot of an F-35 to see and understand the operational environment in a way that no other platform can do it. It’s why I call them the quarterback of the penetrating joint and allied team.’

...[Goldfein] the F-15EX is to solve only one challenge I have, and that is that the F-15Cs are not going to continue flying and I have to have that capacity. I’m not willing to put a nickel of F-35 money into the F-15EX — this is not a trade, this is capacity I need to fulfill a shortfall that’s staring me in the face.’

The solution
The USAF F-15EX will be a two-seat aircraft, aligned with the Advanced F-15, and will be powered by the same General Electric F110-GE-129 Improved Performance Engines....

...The F-15EX will have a large area cockpit display and digital Joint Helmet-Mounted Cueing System (JHMCS). Because partly of the foreign investment in the new displays and management of the systems, everything can be run from the front seat of the EX — the missionized rear cockpit can be optionally occupied by a weapons systems officer. All talk to date has centered on the two-seat EX, not a spin-off single-seat F-15CX. In fact, the USAF has said that F-15C units receiving F-15EXs will operate them with the rear seat unoccupied. Porting the Advanced F-15 into a single-seat CX would require some sort of re-certification of the complex fly-by-wire system, and although the two aircraft retain the same overall dimensions, any risk incurred from new testing may prove unacceptable....

...The F-15EX will directly replace F-15Cs in both active-duty and Air National Guard units, although Goldfein says exact fielding plans still rest with Congress. Plans call for the initial two jets to be provided on a fast timeline to provide extra capacity for the EPAWSS test work, with subsequent aircraft destined for the USAF Weapons School at Nellis AFB, Nevada, and a few joining training activities for the initial conversion process. A source familiar with the discussions told Combat Aircraft that no specific F-15EX testing is planned.

While this acquisition brings about recapitalization of the F-15C fleet, it also enables significant capability advances. The new Advanced Eagles are well-placed to complement the USAF’s large fifth-generation fleet. The air force has been structured with a range of penetrating platforms and a robust fleet of F-22s and F-35s that need to be complemented effectively. The F-15EX will act as a weapon ‘truck’, able to carry the kind of large hypersonic weapons that are in development, but will not fit inside a fifth-generation fighter weapons bay. It will also be able to carry a wide range of armament, all cleared from day one, and enable a versatile development road-map, rather than forcing the USAF to develop specific solutions as new, and previously unforeseen, requirements emerge.”

Source: Combat Aircraft Magazine Oct 2019 Volume 20 No 10

Of course, if they are equipped with the F100-PW-229, the job is easier.

It would be easier for Mx, surely. Mission planning? Maybe not. Looking at the F-16 application the F110-129 offers better supersonic acceleration and, much more importantly, faster cruise speeds at higher cruise altitudes using less fuel per mile when compared to the F100-229.

I still don't understand that. The -229 has a much hotter/higher exhaust velocity, which I thought contributes to high speed efficiency. (Why the old turbojets seem to be faster and fly higher than modern fighters, why the F119 uses a lower bypass ratio etc.)

Ridiculous USAF maintains funds for F-15EX won't compromise the F-35.

I draw the parallel with Russia. They don't yet have a viable 5th gen platform, or certainly an affordable one able to be purchased in large numbers. So they're continuing to buy Flanker derivatives, along with smaller numbers of Mig-35's. All 4th gen aircraft, no matter how many +++ symbols they put by them.

We DO have a very capable, affordable 5th gen platform that.... is now being under-cut by a 4++ airframe. To not stamp out as many F-35's as possible just seems irresponsible. You can bet China would be doing the same, if it too had an F-35 equivalent..

I still don't understand that. The -229 has a much hotter/higher exhaust velocity, which I thought contributes to high speed efficiency. (Why the old turbojets seem to be faster and fly higher than modern fighters, why the F119 uses a lower bypass ratio etc.)

If we are only looking at EGV, then I agree with you, but perhaps the magic is in the higher mass flow rate? I'm not speaking in hypotheticals or formulaic theory, I'm referring to flight manual data from flight tests.

I love P&W, but the GE is clearly the better motor for performance in the F-16. I see no reason it shouldn't translate to the F-15 as well.

... “The F-15EX will act as a weapon ‘truck’, able to carry the kind of large hypersonic weapons that are in development, but will not fit inside a fifth-generation fighter weapons bay. ...
Source: Combat Aircraft Magazine Oct 2019 Volume 20 No 10

Because F-35A can't carry large external weapons ...