F-15EX

Military aircraft - Post cold war aircraft, including for example B-2, Gripen, F-18E/F Super Hornet, Rafale, and Typhoon.
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mixelflick

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Unread post21 Jan 2023, 16:51

I always thought the "Strike Eagle" CFT's on the F-15EX were... confusing.

They're a lot draggier than the C and D's CFT's, and every indication has been the EX will backfill C's in the air to air role. So if they carry CFT's at all, why not the CFT's with less drag? It's not like they're fielding a 4 AMRAAM per CFT loadout, and need the extra hardpoints. In some ways the 2 bag loadout is better..

One F-15C driver summed it up like this, when I asked him why they never flew with CFT's.. "You can punch off the EFT's if you really need to. Can't do that with the CFT's...". Of course, merging is the last resort but I understood his point. I guess time will tell. My money is on the re-introduction of them down the line, when they start replacing worn out F-15E's....
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Unread post21 Jan 2023, 17:33

F15EX max demonstrated speed of M2.49 - was that with or without CFTs? I thought the CFTs had a Mach limit.

F-15EX with -129 engines walked away from F-15E with -229 engines. F-15E always has CFTs, was the EX clean?

Unless the configuration is known, the comparison is pretty much useless.
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Unread post21 Jan 2023, 19:27

f119doctor wrote:F15EX max demonstrated speed of M2.49 - was that with or without CFTs? I thought the CFTs had a Mach limit.

F-15EX with -129 engines walked away from F-15E with -229 engines. F-15E always has CFTs, was the EX clean?

Unless the configuration is known, the comparison is pretty much useless.

My guess is without, as the CFTs have Mach limits (~M1.4).
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disconnectedradical

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Unread post21 Jan 2023, 19:59

I thought F-15 CFTs are 700 knots and Mach 2 limit?
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Unread post21 Jan 2023, 20:24

It's CFT munitions that are 1.4M limited.
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Unread post22 Jan 2023, 13:53

Again, very confusing!

F-15 CFT's mach 2.0 limit, further refined as Mach 1.4 with weapons. OK.... which CFT's? I assume you're talking about the F-15E's bulkier, 6 hardpoints apiece CFT's, vs. the F-15C's (which seem slimmer and usually carry AMRAAM's)?

And if so, then what happens when flying with the various engines? F-100-PW-200? F-100-229's? F-110-129's? If they wanted to confuse people for national security reasons, bravo. Well done!

I guess I'll just stick with what's known about the first batch: F-15EX with GE F-100-129's and no CFT's. That should be the real dragster of the bunch! :mrgreen:
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Unread post22 Jan 2023, 18:24

The F-15Es draggier CFTs are the ONLY ones worthy of discussion because they are the ONLY ones in production and the ONLY ones that have been certified with the F110 motor flight envelope which is why they are the ONLY ones available for the F-15EX. The F-15EX was able to be pushed with no competition because nothing had to be spent on flight sciences testing and certification.
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Unread post23 Jan 2023, 12:16

sprstdlyscottsmn wrote:The F-15Es draggier CFTs are the ONLY ones worthy of discussion because they are the ONLY ones in production and the ONLY ones that have been certified with the F110 motor flight envelope which is why they are the ONLY ones available for the F-15EX. The F-15EX was able to be pushed with no competition because nothing had to be spent on flight sciences testing and certification.


I am not sure if this is so strict.
In the age of the integrated FADEC and digital Fly by Wire relationship, the restriction of the F110GE129, or the Strike Eagle CFT on the F-15EX should not be so hard as the marketing announcement calls for.
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Unread post23 Jan 2023, 14:40

mixelflick wrote:I always thought the "Strike Eagle" CFT's on the F-15EX were... confusing.

They're a lot draggier than the C and D's CFT's, and every indication has been the EX will backfill C's in the air to air role. So if they carry CFT's at all, why not the CFT's with less drag? It's not like they're fielding a 4 AMRAAM per CFT loadout, and need the extra hardpoints. In some ways the 2 bag loadout is better..

One F-15C driver summed it up like this, when I asked him why they never flew with CFT's.. "You can punch off the EFT's if you really need to. Can't do that with the CFT's...". Of course, merging is the last resort but I understood his point. I guess time will tell. My money is on the re-introduction of them down the line, when they start replacing worn out F-15E's....


I guess it all has to do with the mission sets that the F-15EX is expected to fill.

https://www.airandspaceforces.com/artic ... 20fighters.

CAPE and Air Force officials see viable continuing missions for the F-15EX in homeland and airbase defense, in maintaining no-fly zones where air defenses are limited or nonexistent, and in delivering standoff munitions.


These mission profiles prioritize range and loiter time. They're not expected to merge with bandits, where max performance is critical, they have the F-22's for that,

Now if a potential customer plans to use the EX as a frontline air superiority fighter, they can fund a separate program to develop the low drag CFTs.

I noticed that all F-15E and EX operators compliment them with "better performing" aircraft for some reason

Israel has F-16s, F-15A/C and F-35
S.Korea has F-16s and F-35s
Qatar: Mirage 2000, Typhoon and Rafale (maybe the one of the monarchs is a real fighter nerd and wanted everything in the store)
Saudi:F-15As and Typhoons
Singapore: F-16 and F-35 on order

Maybe its just a coincidence but these countries seem to buy the E and EX for very different reasons than for buying the F-15 A-D. It seems they're being purchased as a long range, high payload interceptor/strike platform role and not a high performance frontline air superiority fighter.
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Unread post23 Jan 2023, 15:31

allesmorobranna wrote:
sprstdlyscottsmn wrote:The F-15Es draggier CFTs are the ONLY ones worthy of discussion because they are the ONLY ones in production and the ONLY ones that have been certified with the F110 motor flight envelope which is why they are the ONLY ones available for the F-15EX. The F-15EX was able to be pushed with no competition because nothing had to be spent on flight sciences testing and certification.


I am not sure if this is so strict.
In the age of the integrated FADEC and digital Fly by Wire relationship, the restriction of the F110GE129, or the Strike Eagle CFT on the F-15EX should not be so hard as the marketing announcement calls for.

Watch the video on the previous page, it is that strict and that simple.
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Unread post23 Jan 2023, 17:25

sprstdlyscottsmn wrote:
allesmorobranna wrote:
sprstdlyscottsmn wrote:The F-15Es draggier CFTs are the ONLY ones worthy of discussion because they are the ONLY ones in production and the ONLY ones that have been certified with the F110 motor flight envelope which is why they are the ONLY ones available for the F-15EX. The F-15EX was able to be pushed with no competition because nothing had to be spent on flight sciences testing and certification.


I am not sure if this is so strict.
In the age of the integrated FADEC and digital Fly by Wire relationship, the restriction of the F110GE129, or the Strike Eagle CFT on the F-15EX should not be so hard as the marketing announcement calls for.

Watch the video on the previous page, it is that strict and that simple.


Same story as why the EX has no GE132 engines. The F100PW229 is also possible phisically, but the Congress would not like to spend money for 3-4 years more flight test. So - for me - it is not strict, but simply just not payed/supported. Yet.
From technical standpoint, it is possible, from fianacial/political support side, currently isn't.
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Unread post23 Jan 2023, 17:36

allesmorobranna wrote: from fianacial/political support side, currently isn't.

"No bucks, no Buck Rogers." For the Fiscal/Political reason we both agree on, the E CFT is the only one that will be on the F-15EX, hard stop. No need to discuss further.
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Unread post23 Jan 2023, 18:27

sprstdlyscottsmn wrote:
allesmorobranna wrote: from fianacial/political support side, currently isn't.

"No bucks, no Buck Rogers." For the Fiscal/Political reason we both agree on, the E CFT is the only one that will be on the F-15EX, hard stop. No need to discuss further.


This "no need to discuss further" thing reminds me on the "there is no way to see a Strike Eagle without a CFT in the USAF, hard stop" statements, when suddenly we got some footages of the so-called "Naked Eagles" from Lakenheath. It was not from you, but from others, who like to say hard stop things.
Never say never.

Especially, since the first batch of EX could be arrive without the CFTs - by the current decision of the Air Combat Command.
So the point is not about the E or C/D type CFTs will be on the EX, but will there any CFT on the EX at all?
It seems the USAF/ANG is still looking for the proper role for this highly sophisticated, but mostly a commercially-generated platform.
This CFT-less EX concept seems to be a literally 1:1 F-15C replacement idea, or another nice try from the USAF to abandon this whole purchase
The first one was the 144 to 80 order reduction.

Back to the CFT question. If the EX test flights of that precious Fly by Wire was so strict, it just closed out any deviation from the current layout, it is not allows to apply a different engine, or the lack of CFTs, if the whole test envelope was only managed with the CFTs, why the ACC wants to get them without it?
If the EX's FbW is just a one trick pony, that CFT-less EX will be a complety different airplane. They have to restart the whole flight charateristic test program. It is hard to imagine.
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Unread post23 Jan 2023, 22:29

One of the biggest reasons the F-15 was switched to full fly by wire (it was always partial fly by wire) was to allow stations 1 and 9 (outboard wing stations) to be used, which IIRC in testing caused too much yaw instability to be worth it (with the control scheme of the time)

Any F-15 pilot can tell you the manual warns you in no uncertain terms about how much AoA is (dis)allowed with even moderately asymmetrical loads and something that far out on the wing will have a much larger impact on asymmetry than closer in.
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Unread post23 Jan 2023, 23:30

allesmorobranna wrote:Back to the CFT question. If the EX test flights of that precious Fly by Wire was so strict, it just closed out any deviation from the current layout, it is not allows to apply a different engine, or the lack of CFTs, if the whole test envelope was only managed with the CFTs, why the ACC wants to get them without it?





The FBW and GE-129 engines were incorporated, certified, tested and paid for by Saudi Arabia as part of the F-15SA (first flight 2013).

The F-15QA was the next version of the SA.
The EX is basically the QA with a few mods.

This had to be done on the relative cheap with a fixed budget.

If for example another customer wants to pay for PW-229 engines in it then that could happen, or Boeing put up the money themselves. Fat chance it coming from the USAF budget unless things drastically change.

Regarding the DOTE report - it states that initial EX testing was done with CFTs. The reason the first batch wont have CFTs is as it says because enough CFTs have not been procured and provisioned yet. So it might get CFTs further down the line.
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