Time for 100K lbs of AB Thrust?

[rowbeartoe]

Hello everyone, I hope you are all having a good day.

Stats from Wikipedia.

Early 1960's. The SR-71 had two engines capable of producing a combined total of 68,000lbs of AB thrust thanks to the JT11D-20K.

Fighter Jets:

Mid 1960's. The Mig-25 had two engines combining for a total of 45,000lbs of AB thrust.
Early 1970's. The F-15a had two engines combining for a total of over 47,000lbs of AB thrust.
Mid 1980's. The F-15e had two engines combining for a total of over 58,000lbs of AB thrust.
Early 2000s. The F-16 block 60 with a single GE F110-132 engine could produce 32,500lbs of Ab thrust. (2 would be 65,000lbs)
Mid 2000's. The F-22 had two engines combining for a total of 70,000lbs of AB thrust.
Mid 2010's. The F-35 had one engine that can produce 43,000lbs of AB thrust. (A twin engine version would be 86,000lbs!)

Based on this evolution of engine thrust for fighter Jets, it looks like we might be heading to the AB thrust of 100,000lbs! Perhaps as early of 2025? Perhaps more impressive would be the non AB thrust. The F-35 engine can do 28,000lbs with one engine without AB.

Maybe that means two engines that could produce 100,000lbs of AB thrust would translate to perhaps 70,000lbs without AB?

Anyhow- it's interesting to see the increase over time. I find it fascinating that when the F-22 became operational in 2006 that its thrust was slightly better than the SR-71!

[wrightwing]

Hello everyone, I hope you are all having a good day.

Stats from Wikipedia.

Early 1960's. The SR-71 had two engines capable of producing a combined total of 68,000lbs of AB thrust thanks to the JT11D-20K.

Fighter Jets:

Mid 1960's. The Mig-25 had two engines combining for a total of 45,000lbs of AB thrust.
Early 1970's. The F-15a had two engines combining for a total of over 47,000lbs of AB thrust.
Mid 1980's. The F-15e had two engines combining for a total of over 58,000lbs of AB thrust.
Early 2000s. The F-16 block 60 with a single GE F110-132 engine could produce 32,500lbs of Ab thrust. (2 would be 65,000lbs)
Mid 2000's. The F-22 had two engines combining for a total of 70,000lbs of AB thrust.
Mid 2010's. The F-35 had one engine that can produce 43,000lbs of AB thrust. (A twin engine version would be 86,000lbs!)

Based on this evolution of engine thrust for fighter Jets, it looks like we might be heading to the AB thrust of 100,000lbs! Perhaps as early of 2025? Perhaps more impressive would be the non AB thrust. The F-35 engine can do 28,000lbs with one engine without AB.

Maybe that means two engines that could produce 100,000lbs of AB thrust would translate to perhaps 70,000lbs without AB?

Anyhow- it's interesting to see the increase over time. I find it fascinating that when the F-22 became operational in 2006 that its thrust was slightly better than the SR-71!

There's no tactical aircraft, that will be in service anywhere in 2025, with 100k lbs of thrust. Even in 2035 it's doubtful.

[rowbeartoe]

https://www.yoursurvivalguy.com/weapons ... hter%20jet.

Considering a NGAD flew in late 2020, I'm willing to think at the very least it used the engines the F-35 uses? The F-35 engine is already 15 years old I believe (F-35 first flight). So this NGAD even if it used two of those engines would at least have 86,000lbs of thrust. Now if it uses "newer" engines then maybe, just maybe they made an engine that could go from 43,000 to 50,000lbs of thrust? A 7,000lb improvement 15 years later? I think it's possible.

Just thinking it's possible to at the very least be test flying a new airframe with new engines. At the rate it takes jets to be operational now, that seems very slow if the F-35 is the new model for time frames.

[disconnectedradical]

Static thrust isn’t everything, and what matters more is dynamic thrust and how it operates in right hand side of the envelope. For all the higher thrust figures of the F135 it’s probably got less dynamic thrust than F119 at supersonic parts of the envelope. XA100 will get close to 50k lbf thrust each but again that’s not what the main focus will be.

[wrightwing]

https://www.yoursurvivalguy.com/weapons-of-war/news-of-secret-6th-generation-fighter-jet-takes-flight/#:~:text=News%20of%20Secret%206th-%20Generation%20Fighter%20Jet%20Takes,follow-on%20to%20Lockheed%20Martin%E2%80%99s%20F-22%20stealth%20fighter%20jet.

Considering a NGAD flew in late 2020, I'm willing to think at the very least it used the engines the F-35 uses? The F-35 engine is already 15 years old I believe (F-35 first flight). So this NGAD even if it used two of those engines would at least have 86,000lbs of thrust. Now if it uses "newer" engines then maybe, just maybe they made an engine that could go from 43,000 to 50,000lbs of thrust? A 7,000lb improvement 15 years later? I think it's possible.

Just thinking it's possible to at the very least be test flying a new airframe with new engines. At the rate it takes jets to be operational now, that seems very slow if the F-35 is the new model for time frames.

F-135s have been run at over 50k lbs in tests, but the lifespan of the engine and fuel usage would make it undesirable to operate at that tuning. Even the updated motors are looking at 10-20% thrust improvements, which is still below 50k lbs. Those motors aren't going to be in service in 2025, nor is NGAD. It'll be 2030s before anything is 100k lb combined thrust, operationally.

[h-bomb]

Didn't PW claim that the common tailpipe was limited to 47K or 48K, when GE was claiming the F-136 could go to 52K? This was before the F136 was canceled, and PW responded that the F135 had been tested at the same thrust level?

[sferrin]

Next gen "3-stream" engines from P&W and GE are limited to the F-35's fuselage envelope. HOWEVER, they are also working on a follow on that is NOT constrained by the need to fit in the F-35. That one will be the NGAD engine.

[hkultala]

Next gen "3-stream" engines from P&W and GE are limited to the F-35's fuselage envelope. HOWEVER, they are also working on a follow on that is NOT constrained by the need to fit in the F-35. That one will be the NGAD engine.

Do you think that something like 2*45000 lbs (or even slightly more) is not enough thrust for initial version of NGAD?

That's about twice what f-14 and f-15 initially had, and more than twice what Super Hornet has.

NGAD would have to be insanely big (and expensive) plane to need more thrust than that.

F135 as it is now would not be a good engine for it due to too high bypass ratio making it not so good for supercruise, but the adaptive cycle engines will change that.

[sferrin]

Next gen "3-stream" engines from P&W and GE are limited to the F-35's fuselage envelope. HOWEVER, they are also working on a follow on that is NOT constrained by the need to fit in the F-35. That one will be the NGAD engine.

Do you think that something like 2*45000 lbs (or even slightly more) is not enough thrust for initial version of NGAD?

That's about twice what f-14 and f-15 initially had, and more than twice what Super Hornet has.

NGAD would have to be insanely big (and expensive) plane to need more thrust than that.

Depends on what NGAD is. 50 years ago nobody would have said a single-engined fighter needed 45,000lbs of thrust either yet here we are. Food for thought:

[jetblast16]

Time for 100K lbs of AB Thrust?

Possibly...necessity is the mother of all invention I believe current engine technology will allow for such high thrust levels...if the need(s) arise. A motor that makes ~45K in AB at static conditions may make over this in certain dynamic conditions, particularly at lower altitudes.

[rowbeartoe]

https://www.airforcemag.com/new-force-d ... s-in-2030/
https://en.wikipedia.org/wiki/Next_Gene ... _Dominance

Well only a few will know what engines this NGAD is using, but on wikipedia it's said that the "fighter is expected to leverage adaptive cycle engines being developed under the Adaptive Engine Transition Program (AETP)." This means no F-35 engine to me, so that gives a chance of the 100K lbs of AB thrust vs 86,000lbs with two engines. Also, they claim two models with Range being a thing or not (depending on the model) that sounds like fuel efficiency is important as well. It's going to be interesting to see.

[rowbeartoe]

One thing I just have to say about the F-18 Super Hornet. It's a very capable Jet, but those engines have got to be underpowered for it's weight. I mean an F-15E weighs about the same empty as the SH does (32,000 lbs) yet the AB thrust for the F-15E and EX is slightly over 58,000 vs "only" 44,000 in AB.

[wrightwing]

https://www.airforcemag.com/new-force-design-ngad-needed-soon-f-22-sunset-begins-in-2030/
https://en.wikipedia.org/wiki/Next_Gene ... _Dominance

Well only a few will know what engines this NGAD is using, but on wikipedia it's said that the "fighter is expected to leverage adaptive cycle engines being developed under the Adaptive Engine Transition Program (AETP)." This means no F-35 engine to me, so that gives a chance of the 100K lbs of AB thrust vs 86,000lbs with two engines. Also, they claim two models with Range being a thing or not (depending on the model) that sounds like fuel efficiency is important as well. It's going to be interesting to see.

NGAD may end up with 100k of thrust, but it won't be in service in 2025 (which was the original premise posed.)

[jetblast16]

100K thrust in a fighter-size aircraft = airbreathing rocket

[mixelflick]

One thing I just have to say about the F-18 Super Hornet. It's a very capable Jet, but those engines have got to be underpowered for it's weight. I mean an F-15E weighs about the same empty as the SH does (32,000 lbs) yet the AB thrust for the F-15E and EX is slightly over 58,000 vs "only" 44,000 in AB.

It has long been known the SH is under-powered (continuing the tradition of most "legacy" hornets). It's just part of the compromises made on the jet. But hey, Boeing built 500+ and in so doing pulled the wool over the eyes of a lot of Congressmen. Of course, the jet has its strong points too.

Thrust to weight just generally isn't one of them..