Boeing F-15EX / F-15QA and related variants

Scott Kenny said:
Unfortunate but kinda expected. FFS I think F-35s are cheaper than EXs!
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cheaper is understatement. F-35 is quite affordable; F-15 was always expensive, even when it was built in high numbers.

Furthermore, while F-15EX is indeed the only available /western/ long range western fighter on the market, much of its "sell" (which is FbW and new interfaces, both primarily valuable for future outsized weapons) won't really get too much traction for IN.
CATSA aside, it's really Su-35se for the niche for them. Biggest available kite with most internal fuel for reasonable price.
TomcatViP said:
Remember that 4000km is 1.5x the distance b/w Paris and Moscow.
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Tbf, Rafale has roles(actually relevant ones) which take it far further than Moscow.
They're also fast responce system for entire french colonial Empire, thinly spread across most of the world. And in case of raised tensions around them, it has to be able to reach there, fast, often with armament.
This isn't a pure concept, AdAE demonstrates it every once in a while.
 
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Well, I don't think that the mission to Moscow and beyond you mention is comparable to what the TNI-AF would to plan to do twice or more a day (just in term of attrition and support package) ;)
 
TomcatViP said:
Well, I don't think that the mission to Moscow and beyond you mention is comparable to what the TNI-AF would to plan to do twice or more a day (just in term of attrition and support package) ;)
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Exactly, and that's sort of message. Rafale is pretty clear best MRF on the market for large countries without US-level IFR support.

But if you want to do rather boring peacetime(or wartime for the matter) air patrols for country of this size - checking out missing civilian liners, this sort of job, you need a plane with big tanks. Normally that's flanker, but under CAATSA alternative pitch was F-15EX.

The problem is of course, that IN had to pay twice more upfront(per airframe), and way more still per weapon package. For ultimately sort of secondary role (11-24 planes v. 42 Rafales and likely same 42 J-10s， i.e. ~15-20 percent of procured fleet, and way less overall).
This sounds too much for a niche capability, and Indonesie kept pretense only when faced with strong political pressure of united western front. Indonesia is not Japan(or Russia), very different threat profile. Not like they're building up to resist PLAAF.

If they can slip by and flankers - good for them. If they can't, for this level of overprice, it sort of stop making sense even with politics involved, and may as well try to get it done with Rafales, as @Ozair suggested above.
 
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TomcatViP said:
Fuel fraction is not all. A small aircraft with big tanks will almost certainly be subjected to more drag than a larger one with the same tanks. x

Same with A2A weapons. How many Fox-1 missile can Rafale carries at a comparable range of the F-15EX? A meteor will always drag more than an AMRAAM, with an aggravated impact on a smaller airframe.
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Indeed, generally true. However in this case it's not as clear cut as the F-15's CFTs each create as much drag as an external tank. I was actually surprised to discover this when I read the flight manual... drag index = 20 for 2 CFTs vs. DI=10 per 600 gallon tank. So the F-15 will really be flying with the equivalent of 5x external tanks, 2 of which aren't droppable.

On the other hand, dorsal CFTs have 0 drag penalty in cruise (F-16 and F/A-18E) as they generate enough lift to offset drag. So Rafale with 2 CFTs and 2 external tanks should definitely be cleaner than an F-15 with 3x tanks + CFTs, even adjusting for relative size. And even without CFTs, Rafale's drag shouldn't be any worse with just 2 big tanks + 1 smaller supersonic tank, relative to an F-15 with 3x tanks + CFTs (i.e. 5 tanks).

Missile carriage IMHO has a minor impact on the overall drag comparison. The Rafale has the benefit of 2 wingtip missiles (zero drag) and conformal carriage of 2 missiles. The F-15 with CFTs loses the drag benefit of conformal carriage so all its missiles are dragging, but it has the benefit of being larger which reduces relative drag. Overall likely a wash.
 
H_K said:
Indeed, generally true. However in this case it's not as clear cut as the F-15's CFTs each create as much drag as an external tank. I was actually surprised to discover this when I read the flight manual... drag index = 20 for 2 CFTs vs. DI=10 per 600 gallon tank. So the F-15 will really be flying with the equivalent of 5x external tanks, 2 of which aren't droppable.
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The reasons for the pretty big impact are 1. the many pylons on the type 4 CFTs and 2. the massive weight of the -4 CFTs due to the pylons and associated structure to carry heavy stores.
Compare that to the earlier type 2 CFTs as carried on the F-15C/D: 2487 vs 4367 lbs and drag index 4 vs 20.1
That's the price you pay when turning a fighter into a bomber.

H_K said:
On the other hand, dorsal CFTs have 0 drag penalty in cruise (F-16 and F/A-18E) as they generate enough lift to offset drag. So Rafale with 2 CFTs and 2 external tanks should definitely be cleaner than an F-15 with 3x tanks + CFTs, even adjusting for relative size. And even without CFTs, Rafale's drag shouldn't be any worse with just 2 big tanks + 1 smaller supersonic tank, relative to an F-15 with 3x tanks + CFTs (i.e. 5 tanks).
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Lift = drag. Those CFTs surely don't have zero drag penalty. This is not immediately obvious in the F-16 manual, because the F-16 with CFTs is covered separately i.e. drag is re-baselined to zero. But if you were to compare fuel flow f.e., I'm sure you'd notice the difference.
Btw. F-15 CFTs were also said to create enough lift to carry themselves. But the negative impact on performance is massive.

H_K said:
Missile carriage IMHO has a minor impact on the overall drag comparison. The Rafale has the benefit of 2 wingtip missiles (zero drag) and conformal carriage of 2 missiles. The F-15 with CFTs loses the drag benefit of conformal carriage so all its missiles are dragging, but it has the benefit of being larger which reduces relative drag. Overall likely a wash.
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Drag index of AIM-7 with or without CFTs is 1.8 on the F-15C so no difference.
With the modern CFTs, there is a small penalty: 1.8 vs 2.3
I would not describe Rafale's fuselage mounted missiles as conformal. Those stubby pylons look about as draggy as F-15 CFT pylons.
The wingtip missiles might have a negative drag index even, like on the Hornet.
But I'd say the drag created by AAMs is not a problem in the grand scheme of things.
 
eagle said:
Lift = drag. Those CFTs surely don't have zero drag penalty. This is not immediately obvious in the F-16 manual, because the F-16 with CFTs is covered separately i.e. drag is re-baselined to zero. But if you were to compare fuel flow f.e., I'm sure you'd notice the difference.
Btw. F-15 CFTs were also said to create enough lift to carry themselves. But the negative impact on performance is massive.
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F-16 CFT drag is very minimal.

"The CFTs have very little adverse effect on the F-16's renowned performance," said Maj. Timothy S. McDonald, U.S. Air Force project pilot for CFT testing at Eglin. "You could hardly tell they were there. A set of CFTs carries 50 percent more fuel than the centerline external fuel tank, but has only 12 percent of the drag."
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eagle said:
Lift = drag. Those CFTs surely don't have zero drag penalty. This is not immediately obvious in the F-16 manual, because the F-16 with CFTs is covered separately i.e. drag is re-baselined to zero. But if you were to compare fuel flow f.e., I'm sure you'd notice the difference
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The F-16’s CFTs increase fuel flow by ~0.5% in most subsonic cruise situations… basically a rounding error. The difference only becomes slightly noticeable when going supersonic (~10% slower acceleration from Mach 0.98 to Mach 1.2, ~20% slower from M1.2 to M1.5 etc).

Full performance figures available here for anyone who wants to compare with/without CFTs:
 
Sandboxx has put out a new lengthy video concerning the F-15F*, its capabilities and its missions:


We’ve spoken at length in the past about how the Eagle II’s advanced radar, podded infrared search and track capabilities, and ability to carry oversized weapon systems could all make it an unparalleled missile truck for forward advancing stealth fighters in a high-end fight — there is a solid chance that where the Eagle II really shines in a 21st century near-peer fight, might be right here at home, using this incredible aircraft not as a sword, but rather, as a shield instead.​
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So, let’s talk about using America’s fastest, meanest, and biggest payload-carrying fighter as a roving air defense asset tasked with a fight America has never seen before: stopping enemy cruise missiles from striking deep inside the American mainland.​
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*I refuse to call it by its' non-standard tri-services designation F-15EX.
 
H_K said:
The F-16’s CFTs increase fuel flow by ~0.5% in most subsonic cruise situations… basically a rounding error. The difference only becomes slightly noticeable when going supersonic (~10% slower acceleration from Mach 0.98 to Mach 1.2, ~20% slower from M1.2 to M1.5 etc).
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Yes, you're right, the difference is very small, much smaller than I remembered. Even when accounting for the additional weight.

However, if we assume you also want to carry some weapons, you have to include the drag of the (non jettisonable) A/G pylons. 30 in case of the Viper for two racks.
Of course AAM launchers are much less draggy, but we know the F-15 with type 4/5 CFTs suffers greatly in A/A. But then again, for air to air missions, CFTs are best left at home anyway. :D
 

General Running Air Force Reserve Wants Surplus F-15E Strike Eagles, New F-15EX Eagle IIs​

www.twz.com

General Running Air Force Reserve Wants Surplus F-15E Strike Eagles, New F-15EX Eagle IIs

The chief of the Air Force Reserve Command wants to overturn the depressing trend of aircraft divestments without getting new planes to replace them. The chief of the Air Force Reserve Command wants to overturn the depressing trend of aircraft divestments without getting new planes to replace them.
www.twz.com www.twz.com
 
looks like the aircraft that shot down the Fencers were Qatari F-15QAs, that would mean the first a2a kills by this newer variant
www.ynetnews.com

Iranian bombers were ‘two minutes’ from striking US base before Qatar shot them down

Iranian Su-24 bombers came within minutes of striking Qatar’s Al-Udeid Air Base and a key gas facility before Qatari F-15 fighters shot them down in the air force’s first air-to-air combat mission amid escalating regional attacks
www.ynetnews.com www.ynetnews.com
 
A ME country needs to be paying ~$3-400M for 3-4 new USAF F''15EXs about now.
 
helmutkohl said:
looks like the aircraft that shot down the Fencers were Qatari F-15QAs, that would mean the first a2a kills by this newer variant
www.ynetnews.com

Iranian bombers were ‘two minutes’ from striking US base before Qatar shot them down

Iranian Su-24 bombers came within minutes of striking Qatar’s Al-Udeid Air Base and a key gas facility before Qatari F-15 fighters shot them down in the air force’s first air-to-air combat mission amid escalating regional attacks
www.ynetnews.com www.ynetnews.com
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Kudos to the Qatari pilots but those Iranian pilots have to be respected as well, they must have known there was no way they were coming back from an attack on Al Udeid...
 
Based on internet data on F-15 models & other jets, i made a comparison table b/w F-15 E & EX models.
I tried to find individual load limits of each station, under fuselage & under wings, which is difficult. Mechanical & manufacturing guys can tell better.
Max structural load on ground & limit under high G would be different.
Load chart diagrams of F-15 E are there but not for EX yet.
Hence to distribute 10.4 tons (23,000 lbs) on F-15 E & 13.4 tons (29,500 lbs) on EX, instead of finding combinations of different racks, weapons, fuel tanks, i considered 2 heaviest loads -
- 2x 2000 lb JDAM which can be carried under CFTs
- 3.2 tons or 6,600 lb Silver Sparrow ALBM which can be carried on centerline & inboard wing pylons.

In a strike role, the fuselage alone might be able to handle 16,500 lbs (7.5 tons) -
- 4x 2000 lbs JDAMs under CFTs.
- 7500 lbs of (Silver Sparrow ALBM with launcher rack) on centerline.
- 1000 lb EO sensor pods with racks.

The 2 wings might be able take similar 16,600 lbs (7.55 tons) -
- 2x 7500 lbs (Silver Sparrow ALBM with launcher rack) on inboard wing pylons.
- 2x 800 lbs of (2x AMRAAMs + rack).

Both of above config together may not be used as they'll exceed total qoted load of 10.4 tons on E by 4.65 tons (10,220 lbs), and 13.4 tons on EX by 1.65 tons (3620 lbs).

Empty weight is 48-50%of MTOW, fixed.
Internal+CFT fuel can reach 29-30%, variable.
Under-fuselage & under-wing load can reach 20-21% each, total load 40-42%, variable.
But quoted total load limit is 28-37%, fixed.
So there're overlaps b/w total internal+CFT fuel, max load under fuselage & wings, which can be adjusted as per mission.

1774290712254.png
 
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F-15E and F-15SA have identical internal fuel volumes @ 2019 gallons. I assume the F-15EX is identical to the F-15SA, or do you have sources?
 
F-15SA had their wing replaced to upgraded late configuration with variation in fuel and dry weight. F-15EX has identical wing set. Some F-15E have the original F-15SA wing.

www.robins.af.mil

409th SCMS works with F-15 SPO, AFLCMC to secure RSAF wings for F-15, saving millions

The 409th Supply Chain Management Squadron, along with the Air Force Life Cycle Management Center’s F-15 Program Office and F-15SA Conversion, Fighters and Advanced Aircraft Program Office at Robins
www.robins.af.mil
 
Not exactly. F-15S converted to F-15SA aka F-15SR for Saudi Retrofit got new wings. The removed F-15S wings found their way to USAF F-15Es. Same design, but less hours: F-15E and F-15S use(d) the same wings since the F-15S is a Strike Eagle derivate. Whereas the F-15SA is an advanced Eagle of course.
From the F-15SA manual we know the F-15E and F-15SA have exactly the same internal fuel quantity.

New as in internally different wings were only introduced with the F-15QA variant. The F-15EX presumably uses the same F-15QA wings. But it is unknown if there were any changes in internal fuel capacity. AFAIK, the new wings are stronger and a Boeing proprietary design.
Given the desire to keep any airframe changes to a minimum to avoid FBW changes, I wouldn't count on a bigger fuel capacity. But it's certainly not impossible, since the outer third or so of the F-15 pre QA wing is dry. That's why I asked for sources.

PS: More info regarding the F-15SR rebuild: https://defense-arab.com/vb/threads/174288/

PPS: It's been 13 years already since the F-15SA first flew: https://www.af.mil/News/Article-Display/Article/109548/fly-by-wire-f-15sa-makes-first-flight/
 
eagle said:
New as in internally different wings were only introduced with the F-15QA variant. The F-15EX presumably uses the same F-15QA wings. But it is unknown if there were any changes in internal fuel capacity. AFAIK, the new wings are stronger and a Boeing proprietary design.
Given the desire to keep any airframe changes to a minimum to avoid FBW changes, I wouldn't count on a bigger fuel capacity. But it's certainly not impossible, since the outer third or so of the F-15 pre QA wing is dry. That's why I asked for sources.
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I know that I sure would be looking at filling as much of the wing as possible with fuel with a wing redesign.
 
joshjosh said:
FY27 PB requests 24 F-15 EX
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This budget doesn't make sense in some ways. Like, you have this massive increase in funding for the Air Force and yet they aren't going to increase the purchase of F-15, F-35 or even include new build F-16s? So basically they are just going to continue to allow their airframes to age despite getting a potentially historic increase in funding? That doesn't make any sense.

Either they know or expect this budget request is going to fail, or Congress is going to have to do the heavy lifting on actually determining what programs get funded and how much gets procured for the increase to make practical sense.
 
SlothmanAllen said:
This budget doesn't make sense in some ways. Like, you have this massive increase in funding for the Air Force and yet they aren't going to increase the purchase of F-15, F-35 or even include new build F-16s? So basically they are just going to continue to allow their airframes to age despite getting a potentially historic increase in funding? That doesn't make any sense.
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Aircraft procurement for USAF goes from $30B in FY26 to $30B in FY27. Combat aircraft procurement goes from $14B to $12B. So... yeah.
 
joshjosh said:
Aircraft procurement for USAF goes from $30B in FY26 to $30B in FY27. Combat aircraft procurement goes from $14B to $12B. So... yeah.
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Yeah, that makes no sense. This budget seems incoherent and doesn't make effective use of the money they are requesting. This is the largest budget increase since the Korean War (I believe) and they couldn't find a way to increase aircraft procurement? What the fuck?
 
Desertfox said:
Golden Dome, Hagseth's Lobsters, War costs, and Border Enforcement, are going to take the budget increase...
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Actually, the largest increase from the available documentation is $133B additional RDT&E, of which the largest increase is $54B RDT&E for the Defense Autonomous Warfare Group. Golden Dome actually has a reduction of $3B.
 
Scott Kenny said:
I know that I sure would be looking at filling as much of the wing as possible with fuel with a wing redesign.
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But would you also do that if you consider who's responsible for the design? :p
The original advanced Eagle was delayed by two years or so iirc. Not that bad compared to other programmes actually.
 
eagle said:
But would you also do that if you consider who's responsible for the design? :p
The original advanced Eagle was delayed by two years or so iirc. Not that bad compared to other programmes actually.
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Qatar? Yes, I would.
 
That is disappointing. I had hoped that with how heavily the F-15E is being leaned on, plus the attrition the type has seen in the past month, that we might have started to see signs of increased F-15EX procurement to perhaps recapitalize the F-15E fleet with new birds and divest F-15Es that still have life in them over to the Guard.
 
HaveVoid said:
That is disappointing. I had hoped that with how heavily the F-15E is being leaned on, plus the attrition the type has seen in the past month, that we might have started to see signs of increased F-15EX procurement to perhaps recapitalize the F-15E fleet with new birds and divest F-15Es that still have life in them over to the Guard.
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Production is limited to 24 at this point without some further investment in the production line and the supplier base.
 
EPAWSS is the most concerning aspect of the Eagle crisis.
Israeli birds don't seem to suffer as much despite having their systems exposed to Iran defenses for years now.
 
Judging by pictures of the wreckage in Iran and pictures from 2026 before the war of the other 3 F-15Es that went down, none of those 4 Strike Eagles were equipped with EPAWSS.
USAF might want to reconsider buying AN/AAR-57 MAWS for their F-15EX fleet though.
 
eagle said:
USAF might want to reconsider buying AN/AAR-57 MAWS for their F-15EX fleet though.
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Rather ironic given the ANG delievered EXs have the blisters for the MAWS but no actual AAR-57 fitted.

eq98btvr17lc1.jpeg
 
eagle said:
Judging by pictures of the wreckage in Iran and pictures from 2026 before the war of the other 3 F-15Es that went down, none of those 4 Strike Eagles were equipped with EPAWSS.
USAF might want to reconsider buying AN/AAR-57 MAWS for their F-15EX fleet though.
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This is exactly my meaning. IDF don't have an EPAWSS request but is still able to fly their Eagle over Iran. USAF Eagles seems to have less non- EPAWSS performing ECM then.

Mind that the mission is also probably different. Anything that is tasked to fly low and loiter would suffer hits whatever systems they fly with.
 
TomcatViP said:
EPAWSS is the most concerning aspect of the Eagle crisis.
Israeli birds don't seem to suffer as much despite having their systems exposed to Iran defenses for years now.
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The USAF has only lost one F-15E to adversary action compared to three to friendly fire. Give the volume of sorties flown to date I don't think EPAWSS presence or lack of is really impacting F-15E survivability. TTPs likely have a much greater impact.
 
That´s absolutely true. The ratio of losses Vs accomplished objectives is astonishingly low. Idem for collaterals. When was that that people of a bombed country could stay home watching the event on TV totally safe*? Tell that to Londoners, people from Dresden, St Petersburg or even Hanoi (that, for the latter, were not targeted as much as means were available to make it true then)...

*I hope that the people of Iran do not loose the sense of it
 
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breakingdefense.com

Air Force eyes massive boost for F-15EX fleet - Breaking Defense

The service’s fiscal 2027 budget shows boosts for other aircraft like the F-35 Joint Strike Fighter, while slowing retirements of platforms like the A-10 Warthog.
breakingdefense.com breakingdefense.com

WASHINGTON — The Air Force now plans to buy a total of 267 F-15EX Eagle II fighter jets in the coming years, more than doubling previous projections of the fleet, amid a massive surge in military spending under the Trump administration.
The Air Force’s fiscal 2027 budget, publicly revealed at the Pentagon today, is seeking 24 F-15EXs, a service spokesperson told Breaking Defense. But in the years to come, the Air Force plans to buy dozens more copies of the Boeing-made fighter to build out F-15EX units and “begin to recapitalize the aging F-15E fleet,” the spokesperson said.
Previously, the Air Force planned to buy 129 of the jets. F-15-maker Boeing declined to comment on the Air Force’s plan for a larger fleet.
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raptor82 said:
breakingdefense.com

Air Force eyes massive boost for F-15EX fleet - Breaking Defense

The service’s fiscal 2027 budget shows boosts for other aircraft like the F-35 Joint Strike Fighter, while slowing retirements of platforms like the A-10 Warthog.
breakingdefense.com breakingdefense.com
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Interesting bulk out of the fleet. The intent then is F-15EX moving into the regular air force and not just ANG units. Could also mean the replacement of the whole existing E fleet but at least justifies the -220 fleet being retired.

Of course we have seen this number float up and down previously so could change again in a couple of years with a new administration. Boeing also has a limit on yearly production, which is likely as much the supplier base as it is floor space, which would have to either increase those aspects which won't be cheap or quick especially for the supplier base or export users such as Israel get pushed back.
 

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