Lockheed Martin F-35 Lightning II Joint Strike Fighter (JSF)

[sferrin]

Interesting...for whatever reason the US hasn't based any 5th gen aircraft near the Russian border. In fact I think only a handful of F-22s were sent to Spain. Perhaps it was seen as escalatory to do so.

There are US F-35s over there.

 

[TomcatViP]

4 USAF F-35 regularly fly from NATO countries that share borders with Ukr

See above post 3243 & 3112

Six U.S. F-35A Lightning II fighter jets deployed from Germany to multiple countries on NATO’s eastern flank on Thursday for air policing flights in solidarity with the transatlantic alliance.

 

[kaiserd]

Old news, but the US (and other NATO nations) have deployed F-35s to Germany and neighbours of Ukraine (and hence Russia).

https://www.natomultimedia.tv/app/asset/663288

F-35s, B-52 Arrive at NATO's Eastern Front as Russia Invades Ukraine | Air & Space Forces Magazine

Six F-35s deployed to Germany arrived to the Baltic Sea and Black Sea regions Feb. 24 to reassure Allies as Russian forces move into Ukraine.

www.airforcemag.com

Hill AFB F-35s deploy to Baltic Sea and Black Sea regions near Ukraine

Six F-35 Lightning II jets from Utah’s Hill AFB that deployed to Germany last week have now “forward-deployed” to NATO’s eastern flank near the Baltic Sea and the Black Sea the Air Force said Wednesday.

www.google.com

 

[TomcatViP]

Dutch F-35 landing in Romania:

Four Dutch F-35A Aircraft Have Deployed To Bulgaria To Reinforce NATO's Eastern Flank

The RNLAF F-35s have landed at Graf Ignatievo Air Base, Bulgaria. Four F-35A of the Royal Netherlands Air Force (RNLAF) have deployed to Bulgaria, on Apr.

theaviationist.com

 

[Josh_TN]

I missed the USAF F-35 deployments, thanks.

 

[TomcatViP]

Interview with With Billie Flynn

F-35: Capabilities, Missions, Kinematics, Role In Ukrainian Crisis And Beyond. Interview With Billie Flynn

"The F-35 was designed to operate in highly contested airspace, with capabilities precisely focused on what we have been seeing in Ukraine today." We have

theaviationist.com

 

[TomcatViP]

Aboard The Marine's First F-35B-Packed 'Lightning Carrier' (Updated)

The Marines turned USS Tripoli into a 'Lightning Carrier' packed with over 20 F-35Bs. We were there.

www.thedrive.com

 

[helmutkohl]

^ thanks for posting that! was going to yesterday but forgot.
well America, here is the "light" carrier that some people keep pushing for! (although it seems to be able to carry even more than some stovl carriers in Europe and Asia even).

I assume that in that picture the hanger is empty and that in reality, they'd probably store 7 or 8 of those aircraft downstairs.
still might be a bit cramp?

 

[Archibald]

It is a brilliant move really. The USN always refused to go the CVV way for good and bad reasons: essentially it would be an inferior ship threatening its supercarriers.
So they pulled the "light carrier" out of the USMC amphibious, once they grew large enough (30 000 to 50 000 tons). By slightly tweaking the largest amphibious, trading the well deck and hospital facilities for an improved F-35 capability.

The F-35 "package" (AMRAAM + stealth + supersonic + VSTOL) helped that to happen.

Way to go !

 

[TomcatViP]

^ thanks for posting that! was going to yesterday but forgot.
well America, here is the "light" carrier that some people keep pushing for! (although it seems to be able to carry even more than some stovl carriers in Europe and Asia even).

I assume that in that picture the hanger is empty and that in reality, they'd probably store 7 or 8 of those aircraft downstairs.
still might be a bit cramp?

Doesn't seem too bad (source: same link as above)

 

[helmutkohl]

^ sorry, the way I typed it made it seem like I was referring to the hangar being cramped.
I was thinking of the flight deck. If you moved 8 of them down stairs.
the top deck still seems a big cramp. (you're basically moving one row of the f-35s in the front, or the group of F-35s in the back).

 

[EwenS]

From above you get a better feel for the available space, or lack of it.

https://theaviationist.com/wp-content/uploads/2022/04/F-117-F-35B-3.jpg

And this with a diagram of the layout for flight operations with 22 aboard. But one permanently on the starboard lift seems a bit unworkable as does the one on the take off run. So 20 is probably the max. IIRC the forward hangar bay is reduced height.

Here's The USMC's Plan For "Lightning Carriers" Brimming With F-35Bs

The concept is a modern and much more potent iteration of the "Harrier Carrier" concept that has been used in the past.

www.thedrive.com

 

[Archibald]

Don't forget the largest USMC amphibs tonnage is a bit more than freakkin' Charles de Gaulle carrier: 45 000 tons. Plus their hull shape and propulsion plants are not only designed for lower speeds (much less than 27 kt), but also to house voluminous landing vehicles.

So there is probably plenty of room inside, and even more without a well deck and reduced hospital facilities.

I wonder if an angled deck could be added just to push the basic concept a little further ? Although F-35B don't expressly need it. And it may carry the idea too far from USMC amphibs and uncomfortably close from USN carriers...

 

[Josh_TN]

From above you get a better feel for the available space, or lack of it.

https://theaviationist.com/wp-content/uploads/2022/04/F-117-F-35B-3.jpg

And this with a diagram of the layout for flight operations with 22 aboard. But one permanently on the starboard lift seems a bit unworkable as does the one on the take off run. So 20 is probably the max. IIRC the forward hangar bay is reduced height.

Here's The USMC's Plan For "Lightning Carriers" Brimming With F-35Bs

The concept is a modern and much more potent iteration of the "Harrier Carrier" concept that has been used in the past.

www.thedrive.com

Actually that layout has seven forward, seven aft, and seven in the hanger...so the aircraft on the elevator might just be notionally one of the seven from the hanger being moved; if you take that one out you have twenty aircraft.

The USN was sufficiently impressed with their first F-35 deployment that they are already talking about growing the squadron to 14 or perhaps embarking two of ten for twenty. Everything I've read about actual deployments seems to indicate that F-35 is a huge leap forward in situational awareness electronically; everyone wants more.

 

[Bhurki]

I understand the enthusiasm about the light carrier concept and the mobile basing and new attack vectors that it opens up.
However, we still need to keep in mind the limitations of such a platform. An LHA has just about enough room (10k cuft for armament) and fuel to maintain 'light carrier' ops tempo for a couple of days.
Severe limitations like mobility of the platform itself along with curtailed capability of a 'half airwing' means that you still need to have various support assets attached to it for it to function properly.

 

[rooster]

I understand the enthusiasm about the light carrier concept and the mobile basing and new attack vectors that it opens up.
However, we still need to keep in mind the limitations of such a platform. An LHA has just about enough room (10k cuft for armament) and fuel to maintain 'light carrier' ops tempo for a couple of days.
Severe limitations like mobility of the platform itself along with curtailed capability of a 'half airwing' means that you still need to have various support assets attached to it for it to function properly.

Its a force multiplier for full size carriers and many unfriendly nations can't sustain a fight against such a light carrier.

 

[sferrin]

From above you get a better feel for the available space, or lack of it.

https://theaviationist.com/wp-content/uploads/2022/04/F-117-F-35B-3.jpg

And this with a diagram of the layout for flight operations with 22 aboard. But one permanently on the starboard lift seems a bit unworkable as does the one on the take off run. So 20 is probably the max. IIRC the forward hangar bay is reduced height.

Here's The USMC's Plan For "Lightning Carriers" Brimming With F-35Bs

The concept is a modern and much more potent iteration of the "Harrier Carrier" concept that has been used in the past.

www.thedrive.com

Actually that layout has seven forward, seven aft, and seven in the hanger...so the aircraft on the elevator might just be notionally one of the seven from the hanger being moved; if you take that one out you have twenty aircraft.

The USN was sufficiently impressed with their first F-35 deployment that they are already talking about growing the squadron to 14 or perhaps embarking two of ten for twenty. Everything I've read about actual deployments seems to indicate that F-35 is a huge leap forward in situational awareness electronically; everyone wants more.

If only they felt that way about the C's on the CVNs. They could easily support two squadrons of 12 aircraft without giving up anything. Two of those, two Super Hornets, a squadron of Growlers, and you're still only at 60 aircraft. Add half a dozen MQ-25s, 4 E-2Ds, 4 CMV-22Bs, 10 helos, and you're at 84.

 

[Josh_TN]

Weird thought concerning managing the F-35s on amphibs. Would it be at all possible or practical to take off towards the stern of the ship? This would definitely reduce the lift of the aircraft due to the lack of forward motion, but for a STOVL type with low drag I would imagine it was possible. This would allow for a aircraft parked towards the front of the deck to not have to be repositioned astern. Possible? Practical? Too confusing for deck crews? In any case I admit it really would only be useful for an "alpha strike" scenario where you want to sortie most of the wing at once. Lower launch rates would recomend conventional deck move movement.

 

[Dragon029]

It should be possible (unless there's something at the stern that could snag a landing gear), and to some extent has been tested; IIRC during the operational testing aboard the Queen Elizabeth for example they mentioned that they tested vertical landing while facing the stern.

However, I think unless there's an emergency where the ship has lost propulsion / steering, the wind over the deck is in the wrong direction and there's an immediate need to launch fighters, it won't happen, just because the time spent taxiing a jet ~500 feet probably won't be that big of a deal when also factoring in the need to reposition deck crew, etc.

I could be wrong, but I think the circumstances would have to be very niche to make sequential forward-then-aft launches the best course of action.

 

[NeilChapman]

I understand the enthusiasm about the light carrier concept and the mobile basing and new attack vectors that it opens up.
However, we still need to keep in mind the limitations of such a platform. An LHA has just about enough room (10k cuft for armament) and fuel to maintain 'light carrier' ops tempo for a couple of days.
Severe limitations like mobility of the platform itself along with curtailed capability of a 'half airwing' means that you still need to have various support assets attached to it for it to function properly.

Its a force multiplier for full size carriers and many unfriendly nations can't sustain a fight against such a light carrier.

It's a nice idea as well if one plan for F-35B's is to have them forward deployed inside the A2AD area. You can bring these jets forward wo endangering a CSG.

 

[icyplanetnhc (Steve)]

Relevant excerpt from General Nahom. Full Q&A in the links below.

Part 1: Q&A with Lt. Gen. David S. Nahom on the Future Fighter Fleet | Air & Space Forces Magazine

Lt. Gen. David S. Nahom, Air Force deputy chief of staff for plans and programs, spoke about the future of fighters, tankers, bombers, and more.

www.airforcemag.com

Part 2: Q&A With Lt. Gen. David S. Nahom on the Future Fleets | Air & Space Forces Magazine

Part 2 of an exclusive wide-ranging interview with Lt. Gen. David S. Nahom, Air Force deputy chief of staff for plans and programs.

www.airforcemag.com

Air Force Magazine: Let’s do a two-minute elevator speech on the five-year defense program. So we understand that we’re going to bring down the F-35s, we’re investing in NGAD, and we’re paying for nuclear, and so on. But some of that, … like the F-35, we can’t see, where does that go in Year 2, 3, 4, 5? … We’re not asking you to go line item by line item.

Nahom: Yeah, in general, the F-35 is gonna be a big one. Because, as you saw, the number is a little lower than it was last year.

Air Force Magazine: A lot lower.

Nahom: I will say, though, … we have not backed off our investment in the F-35. … When the F-35 was first brought on as a developmental program 20-plus years ago, there was a different threat. And as the threat has evolved, the systems that we need to put on the F-35 have evolved. And there’s a cost there. When you talk about getting to the next block of the F-35, and the systems we need for a peer fight, we are investing quite a bit of money on the F-35, and we intend to get not only that capability, but eventually get the capacity we need too. There are limits though. Would we have bought more F-35s if we had more resources? Yes, absolutely.

The Chief has been very consistent, and going back to [former Chief of Staff Gen. David L. Goldfein] too, we’ve said we seek 72 new fighters a year. And what does 72 new fighters a year do? … Our fighter fleet age continues to rise. When you get to 70-plus fighters, we actually start taking the age down, and we start getting some of these older platforms [out].

I tell you, we never intended for some of these platforms to be in service this long. I mean, there’s no reason F-15Cs—and I grew up in the F-15C—there’s no reason we should still be flying it right now. We should have recapitalized those squadrons with new airframes by now. So we’ve got to get to the numbers.

Now, the threat says we’ve got to get to the [future] capability. In a perfect world, would I like the capability and a lot more F-35s—and [F-15]EXs? Absolutely. But, right now we’ve got to concentrate on making sure we get the F-35 we need. We continue the development, and then we buy as many as we can. And if we can get more, then there’s some goodness there.

 

[TomcatViP]

The F-35 has radar, infrared, and other sensors that form a picture hundreds of miles into Ukraine and Belarus, gathering information that is displayed on the cockpit screen, shared with allied F-35s on Air Policing missions nearby, and relayed to NATO command centers.

The U.S. government has publicly said it shares intelligence with Ukraine that is helping the country to produce battlefield successes. The 34th Fighter Squadron pilots would not say if the data their aircraft gather on Air Policing missions contributes to that picture, but U.S. Air Forces in Europe confirmed that information collected through a variety of platforms adds up to a common intelligence picture.
[...]
NATO Air Policing is the deterrence measure meant to ensure that boundary in the sky is not crossed.

“When we go up there, it’s not just a Wisconsin dude sitting in a gray aircraft up there,” said Sweeney. “It’s a representative of what NATO’s mission is: to deter, train, and provide readiness.”

Harvey spoke of the “honor” of being the execution arm of the NATO deterrence policy.

“You can see for miles and miles, just with your own eyes up there,” he said.

“You can look out, and you can see Lviv, for example, and it’s just particularly moving, knowing that all is right there,” he added, reflecting on the war and his NATO mission. “It has been, and I pray, will continue to be a purely defensive part.”

Spangdahlem Delivers F-35 Air Power to the Eastern Flank | Air & Space Forces Magazine

Spangdahlem Air Base, Germany, has become an air power projection point for the NATO Eastern Flank, including with F-35 Air Policing.

www.airforcemag.com

 

[TomcatViP]

Air Force's math on the F-15EX and F-35 doesn't add up - Breaking Defense

In a new op-ed, JV Venable of the Heritage Foundation goes deep on Air Force budget figures to answer the question of which is more expenses, the F-35A or F-15EX.

breakingdefense.com

With an interesting price breakdown document under excel available here

F15EX vs F35 costs

t.co

Remark:
I had no idea that Legion pod was so expensive

 

[GTX]

Britain confirms plans to purchase 74 F-35B jets

The head of the Royal Air Force has confirmed plans to purchase 74 F-35B jets adding that it is "possible" the UK may eventually have a fleet of 138 F-35s.

ukdefencejournal.org.uk

 

[Dreamfighter]

Britain confirms plans to purchase 74 F-35B jets

The head of the Royal Air Force has confirmed plans to purchase 74 F-35B jets adding that it is "possible" the UK may eventually have a fleet of 138 F-35s.

ukdefencejournal.org.uk

I would have preferred to see them buy not just more F-35B´s but also some F-35C (or A), which could be fitted with the new adaptive-cycle engine.
And to see the RN add catapults to the Queen Elizabeth carriers. Too bad costs for that went up too much and it was cancelled.

 

[rooster]

Well if there is another war (big war) in Europe, the B is a better choice than the C because Britain's runways will be smoked. The performance penalty over the C isn't that much of a difference to matter

 

[TomS]

Well if there is another war (big war) in Europe, the B is a better choice than the C because Britain's runways will be smoked. The performance penalty over the C isn't that much of a difference to matter

How? Considering that Russia has failed to close the runways of even the Ukranian Air Force? Barring nukes, it's very hard to see how Russia has the wherewithal to mount an effective offensive counterair campaign that far beyond its borders. And if nukes come in, who cares what version of F-35 you have?

 

[Dreamfighter]

Well if there is another war (big war) in Europe, the B is a better choice than the C because Britain's runways will be smoked. The performance penalty over the C isn't that much of a difference to matter

Performance penalty won´t be much of a difference until the C gets equipped with the new engine, which (today) seems not to be possible for the B. The adaptive engine will not only provide lower fuel-consumption and increased range and thrust, but will also offer an important increase in cooling.

 

[Forest Green]

The A would surely be the best option. Our carriers have no cat so the C is useless for us. The A can carry a slightly better array of internal weapons and has better range than the B.

 

[Josh_TN]

The C also has the heaviest empty weight and lowest acceleration of the the three AFAIK.

 

[icyplanetnhc (Steve)]

New Leadership Reimagines U.S. Air Force Fighter Fleet Structure | Aviation Week Network

F-35 and F-15EX programs face near-term cuts as U.S. Air Force makes new push for Next-Generation Air Dominance.

aviationweek.com

Some relevant excerpts.

Although the Lockheed Martin F-35A is the only feasible alternative [to the F-15EX] as an F-15C/D replacement in the near term, the Air Force instead aims to slash planned orders for the stealthy, single-engine fighter over the next two years by as many as 34 jets, then ramp up orders after F-15EX procurement is completed in fiscal 2024. The 33-year-old F-15E fleet, meanwhile, emerges from the fighter reshuffling unscathed.

...

Air Force officials are seeking to finance new fighter capabilities such as NGAD and F-35 Block 4 by retiring aircraft in the short term. The strategy has usually been met with resistance by Congress. Indeed, the Air Force’s total aircraft inventory in fiscal 2022 comes out about even with the fiscal 2018 fleet, despite proposals to retire hundreds of aircraft over the five-year period.

At the same time, Kendall has proposed reengining the F-35. The Pratt & Whitney F135 is meeting specifications, but Block 4 electronic upgrades risk overwhelming the power and thermal management system. Pratt designed the 43,000-lb.-thrust engine to provide bleed air from the compressor to cool the onboard electronics. But the Block 3F electronics introduced in 2016 already demand twice the optimal 15 kW of bleed-air offtake. The Block 4 upgrades, which include a new core processor, will require a 47-kW offtake from the compressor.

The Air Force is debating whether to upgrade the F135 or shift to the product of the Advanced Engine Technology Development program. The candidates include the GE Aviation XA100 or Pratt XA101 turbofans, which feature adaptive controls for bypass flow that can offer at least a doubling of cooling capacity compared with the F135.

 

[Forest Green]

The C also has the heaviest empty weight and lowest acceleration of the the three AFAIK.

Unless you have a CATOBAR carrier, the C is basically irrelevant.

 

[Dreamfighter]

The C also has the heaviest empty weight and lowest acceleration of the the three AFAIK.

And the B will remain the one with the lowest range and lowest combat-load.
So, "choose wisely."

 

[Ronny]

New Leadership Reimagines U.S. Air Force Fighter Fleet Structure | Aviation Week Network

F-35 and F-15EX programs face near-term cuts as U.S. Air Force makes new push for Next-Generation Air Dominance.

aviationweek.com

Some relevant excerpts.

Although the Lockheed Martin F-35A is the only feasible alternative [to the F-15EX] as an F-15C/D replacement in the near term, the Air Force instead aims to slash planned orders for the stealthy, single-engine fighter over the next two years by as many as 34 jets, then ramp up orders after F-15EX procurement is completed in fiscal 2024. The 33-year-old F-15E fleet, meanwhile, emerges from the fighter reshuffling unscathed.

...

Air Force officials are seeking to finance new fighter capabilities such as NGAD and F-35 Block 4 by retiring aircraft in the short term. The strategy has usually been met with resistance by Congress. Indeed, the Air Force’s total aircraft inventory in fiscal 2022 comes out about even with the fiscal 2018 fleet, despite proposals to retire hundreds of aircraft over the five-year period.

At the same time, Kendall has proposed reengining the F-35. The Pratt & Whitney F135 is meeting specifications, but Block 4 electronic upgrades risk overwhelming the power and thermal management system. Pratt designed the 43,000-lb.-thrust engine to provide bleed air from the compressor to cool the onboard electronics. But the Block 3F electronics introduced in 2016 already demand twice the optimal 15 kW of bleed-air offtake. The Block 4 upgrades, which include a new core processor, will require a 47-kW offtake from the compressor.

The Air Force is debating whether to upgrade the F135 or shift to the product of the Advanced Engine Technology Development program. The candidates include the GE Aviation XA100 or Pratt XA101 turbofans, which feature adaptive controls for bypass flow that can offer at least a doubling of cooling capacity compared with the F135.

This is kinda interesting.
So basically the optimal cooling from the compressor is 15kW, but it can provide up to 30 kW since block 3F?

 

[Forest Green]

And the B will remain the one with the lowest range and lowest combat-load.
So, "choose wisely."

Well we need the B for the STOVL carriers, and I think the remainder should be As. 6 squadrons of each is probably the best we can hope for.

 

[F119Doctor]

New Leadership Reimagines U.S. Air Force Fighter Fleet Structure | Aviation Week Network

F-35 and F-15EX programs face near-term cuts as U.S. Air Force makes new push for Next-Generation Air Dominance.

aviationweek.com

Some relevant excerpts.

Although the Lockheed Martin F-35A is the only feasible alternative [to the F-15EX] as an F-15C/D replacement in the near term, the Air Force instead aims to slash planned orders for the stealthy, single-engine fighter over the next two years by as many as 34 jets, then ramp up orders after F-15EX procurement is completed in fiscal 2024. The 33-year-old F-15E fleet, meanwhile, emerges from the fighter reshuffling unscathed.

...

Air Force officials are seeking to finance new fighter capabilities such as NGAD and F-35 Block 4 by retiring aircraft in the short term. The strategy has usually been met with resistance by Congress. Indeed, the Air Force’s total aircraft inventory in fiscal 2022 comes out about even with the fiscal 2018 fleet, despite proposals to retire hundreds of aircraft over the five-year period.

At the same time, Kendall has proposed reengining the F-35. The Pratt & Whitney F135 is meeting specifications, but Block 4 electronic upgrades risk overwhelming the power and thermal management system. Pratt designed the 43,000-lb.-thrust engine to provide bleed air from the compressor to cool the onboard electronics. But the Block 3F electronics introduced in 2016 already demand twice the optimal 15 kW of bleed-air offtake. The Block 4 upgrades, which include a new core processor, will require a 47-kW offtake from the compressor.

The Air Force is debating whether to upgrade the F135 or shift to the product of the Advanced Engine Technology Development program. The candidates include the GE Aviation XA100 or Pratt XA101 turbofans, which feature adaptive controls for bypass flow that can offer at least a doubling of cooling capacity compared with the F135.

This is kinda interesting.
So basically the optimal cooling from the compressor is 15kW, but it can provide up to 30 kW since block 3F?

Yes, the F135 is supplying 30kW of bleed flow for 3F. However, this requires the engine to run hotter and faster to offset this diversion of core airflow, which reduces hot section life, driving the power module back to depot sooner than planned.

 

[GTX]

Almost cracked the 800 aircraft delivered mark:

https://www.f35.com/content/dam/lockheed-martin/aero/f35/documents/F-35%20Program%20Lightning%20II%20Fast%20Facts%20-%20May%202022.pdf

 

[Ronny]

New Leadership Reimagines U.S. Air Force Fighter Fleet Structure | Aviation Week Network

F-35 and F-15EX programs face near-term cuts as U.S. Air Force makes new push for Next-Generation Air Dominance.

aviationweek.com

Some relevant excerpts.

Although the Lockheed Martin F-35A is the only feasible alternative [to the F-15EX] as an F-15C/D replacement in the near term, the Air Force instead aims to slash planned orders for the stealthy, single-engine fighter over the next two years by as many as 34 jets, then ramp up orders after F-15EX procurement is completed in fiscal 2024. The 33-year-old F-15E fleet, meanwhile, emerges from the fighter reshuffling unscathed.

...

Air Force officials are seeking to finance new fighter capabilities such as NGAD and F-35 Block 4 by retiring aircraft in the short term. The strategy has usually been met with resistance by Congress. Indeed, the Air Force’s total aircraft inventory in fiscal 2022 comes out about even with the fiscal 2018 fleet, despite proposals to retire hundreds of aircraft over the five-year period.

At the same time, Kendall has proposed reengining the F-35. The Pratt & Whitney F135 is meeting specifications, but Block 4 electronic upgrades risk overwhelming the power and thermal management system. Pratt designed the 43,000-lb.-thrust engine to provide bleed air from the compressor to cool the onboard electronics. But the Block 3F electronics introduced in 2016 already demand twice the optimal 15 kW of bleed-air offtake. The Block 4 upgrades, which include a new core processor, will require a 47-kW offtake from the compressor.

The Air Force is debating whether to upgrade the F135 or shift to the product of the Advanced Engine Technology Development program. The candidates include the GE Aviation XA100 or Pratt XA101 turbofans, which feature adaptive controls for bypass flow that can offer at least a doubling of cooling capacity compared with the F135.

This is kinda interesting.
So basically the optimal cooling from the compressor is 15kW, but it can provide up to 30 kW since block 3F?

Yes, the F135 is supplying 30kW of bleed flow for 3F. However, this requires the engine to run hotter and faster to offset this diversion of core airflow, which reduces hot section life, driving the power module back to depot sooner than planned.

Do you have additional source for that or it come from your experience working on these engine?.
Anyway, I find this pretty interesting since F-18E/F intended to provide 15kW liquid cooling for APG-79. Given that APG-81 has a bit more T/R modules than APG-79 (1626 modules vs 1368 modules), I wonder what the cooling requirement for APG-81 would be. Maybe 19-20kW?

 

[Ronny]

I vaguely remember the cooling capacity of F-15E to be around 35-40 kW as well

 

[F119Doctor]

Yes, the F135 is supplying 30kW of bleed flow for 3F. However, this requires the engine to run hotter and faster to offset this diversion of core airflow, which reduces hot section life, driving the power module back to depot sooner than planned.

Do you have additional source for that or it come from your experience working on these engine?.
Anyway, I find this pretty interesting since F-18E/F intended to provide 15kW liquid cooling for APG-79. Given that APG-81 has a bit more T/R modules than APG-79 (1626 modules vs 1368 modules), I wonder what the cooling requirement for APG-81 would be. Maybe 19-20kW?

View attachment 677766

39 years as a Customer Support / Field Service Engineer for P&W

Taking bleed air from the core airflow is a double penalty for engine performance. All of the air taken from the compressor has absorbed turbine power to get it pressurized - this lost turbine power has to be offset by pushing more fuel and temperature into the combustor. And this air is no longer available to drive the turbine, which means further fuel and temp increase. And the impact is increased at altitude where air density is lower but the cooling demands remain relatively constant.

This increased bleed flow pushes up the operating temperatures throughout the flight envelope. The engine performance is reduced when against the max operating limits, and the temperatures are increased at all other operating conditions, cumulatively using up available hot section life.