Forum: F-35 Engine

It sounds like a good explanation to me. I recall reading an article somewhere the possibility of using advancements from the F135 to allow 10 to 15 year equivalent TBO for the F119 compressors. I don't know how true or possible that is but it does signify to me that the F135 is not merely an F119 with a different Bypass Ratio. It's a very advanced motor, as you stated, designed for different purposes. It should be a beast. JL Raleigh NC

F-16.net Sponsor

What would have been a beast, the YF-120 variable cycle, dual bypass engine from the YF-23!
More advanced than the F-119. It acted as a turbofan at lower speeds, a turbojet at higher speeds. Some people say that the YF-23 set the record for high speed supercruise at around Mach 1.8. The real figures are still classified. This of course would not be down to the motors alone, aerodynamics playing a part also.

I find it hard to believe that the F-119 is identical to the F-135. The engine cores might be the same but the fuel and control systems, bleed air systems (if any) might well be different.

A question I have about the F-135 is; can an F-135 in a JSF A model be bolted to a JSF B and C model? I saw somewhere, I forget where, that there are slight differences. I have even seen different designations, F-135-100. F-135- 200 and F-135-600? Each one for the different versions. Now, the B model has a narrower rear fuselage for example, there are other major differences in the other models, it sounds about right that there would be motors suited to the different models.... any thoughts or info?

Quote:

What would have been a beast, the YF-120 variable cycle, dual bypass engine from the YF-23!
More advanced than the F-119. It acted as a turbofan at lower speeds, a turbojet at higher speeds. Some people say that the YF-23 set the record for high speed supercruise at around Mach 1.8. The real figures are still classified. This of course would not be down to the motors alone, aerodynamics playing a part also.

The F22 is listed as <mach 1.72 to <1.78 by the USAF, and Gen. Jumper. They always say "greater than". Aerofax has it as 1.8. It's true the prototype F23 was faster than the 22, but was exceeded by production raptors. Top speed is now mach 2+, as opposed to mach 1.8 with the prototype/original figures released.

I had originally heard the F136 was going to be developed from the F120. I haven't a clue if it was. As far as Bolt in I don't know. The 135 and 136 were supposed to be plug and play switchable on the same aircraft. JL raleigh NC

Yes, the 136 used the core of the YF-120 and so should have had the variable cycle design. If they didn`t obviously it couldn`t be based on that engine! The design obviously worked on the YF-23.
The F-22 figures of M2, were they supercruise speeds? Or with re-heat? If it can cruise at M2 without re-heat for long periods I am astonished! That is awesome. The 1.8 Mach figure for the YF-23 was supposedly in cruise without afterburners.

Guess we will have to wait some years to find out!

Last edited by The_Mastiff on Feb 16, 2006 - 09:27 AM; edited 1 time in total

Quote:

The F-22 figures of M2, were they supercruise speeds?

No, the greater than mach 2 ( mach 2+) is in burner. The greater than mach 1.78 figure ( some sources now say mach 1.8) is military power. The YF 23 was faster with both engines comparitively though. The F120 engine produced the greater speeds in both aircraft, but they don't say how much.

The reason it wasn't chosen despite it's greater potential was it was newer technology and they figured there would be less trouble with the more proven style engine though they did admit back then the 120 had the greater potential of the two. Though I know of no other articles besides the "Nasty engine" article claiming 56, 000 lbs of thrust that you referred too, Andy might be right about the F136's potential being greater if in fact it was like the F120. Like you say it'll be some time before the real story is released. We do have P&W claims of making the same power now, and that's about all that I know of. JL Raleigh NC

The_Mastiff wrote:

It's true the prototype F23 was faster than the 22, but was exceeded by production raptors. Top speed is now mach 2+, as opposed to mach 1.8 with the prototype/original figures released. JL raleigh NC

I remember a while back when they (USAF) listed the "Top/Max Speed" of the F-22 as "Mach 1.8." Oh man, was that funny! Laughing

Sorry, can't help myself.

There's just a new press release out:

Pratt & Whitney and Rolls-Royce continued collaboration on Joint Strike Fighter propulsion system

Pratt & Whitney and Rolls-Royce have signed a Memorandum of Understanding to define their future collaboration on the F135 propulsion system for the F-35 Joint Strike Fighter (JSF).

<a href="news_article1625.html">Read more</a>

Thanks Lieven!

Looks like RR may get sustainment contracts then! Not as good as the business the 136 engine business may have been. Better than nothing though. Wonder if this has been pushed by the US government as a sweetener?, i.e. Blair/Bush.

To be fair to Rolls, they do have a lot of STOVL experience and expertise as said.

I just now read the article Lieven provided. I did not know that RR was involved in the F135 at all. That seems kind of strange to me. I mean, weren't they developing a competing design (F136)? Also, I don't see what Tony Blair is so upset about. It seems that the UK is still going to have a stake in the F-35.

Quote:

U.S. DoD Plan for Single-Supplier of JSF Engines Hits Flak

By William Matthews

The Pentagon’s plan to save $1.8 billion by dropping one of the engine suppliers for the Joint Strike Fighter (JSF) is flying into flak in Congress.

A Republican and a Democrat on the House Appropriations defense subcommittee questioned Feb. 16 whether short-term savings gained by canceling a contract awarded to General Electric (GE) and Rolls-Royce would lead to a repeat of problems the military has had before with high-cost, poor-performing engines from a single supplier.

“In the long run, it will cost money,” Rep. David Hobson, R-Ohio, warned Defense Secretary Donald Rumsfeld.

Reverting to a single engine producer for the JSF would mean that GE “will go out of the fighter engine business,” Hobson said. And that would mean that the Pentagon would be left to buy thousands of JSF engines solely from Pratt & Whitney.

“Congress will have a lot of heartburn over this,” Hobson predicted.
Rep. Peter Visclosky, D-Ind., reminded Rumsfeld that during the 1980s, the Navy and Air Force struggled with problematic Pratt & Whitney engines until they finally turned to GE as a second source.

When faced with competition, Pratt’s quality went up and its prices went down, according to defense analysts.

Visclosky asked Rumsfeld whether, in addition to calculating an immediate saving of $1.8 billion, the Defense Department had considered the long-term savings that might be achieved by having two companies compete to sell the military engines for more than 3,000 Joint Strike Fighters “Obviously, in life it would be great to have a belt and suspenders,” Rumsfeld replied. But the Defense Department has decided that “there are better things that we could do with a billion-eight” than spend it on developing a second source for JSF engines.

The apprehension of the two appropriators parallels alarm expressed by Ohio’s two senators in a letter Feb. 8.

“Eliminating the second-source engine for the JSF ultimately could lead to a reduction in overall engine quality and noncompetitive pricing,” Sens. Mike DeWine and George Voinovich wrote to Sen. John Warner, chairman of the Senate Armed Services Committee.

“History proves that dual-source competition produces a better, safer, more reliable and less expensive product,” they wrote.

They also warned that canceling the second-source engine contract would mean “General Electric will be forced to exit the fighter engine arena,” leaving the Defense Department with only one source “for all its future fighter engine needs. This is not sound business.”

A day earlier during an Armed Services Committee hearing, Warner told Rumsfeld that his committee would pay “careful attention” to the plan to drop the GE-Rolls-Royce team.

“I think we have a responsibility, particularly because the international aspects of this program and particularly Great Britain, who has been our most steadfast partner in the Iraqi coalition,” Warner said.

In January, British Prime Minister Tony Blair unsuccessfully lobbied U.S. President George W. Bush to keep money in the 2007 defense budget for the GE-Rolls-Royce team.

The team received a $2.4 billion contract last August to be the second JSF engine producer.

In addition to questions of cost, quality and aid for allies, there is a question of jobs. About 800 workers are employed at a GE Aircraft Engines assembly plant in Evendale, Ohio. Canceling the GE-Rolls-Royce contract “would be a severe loss to Ohio and the defense community,” DeWine and Voinovich said.

London-based Rolls-Royce operates a facility in Indianapolis.

Source: http://staging.defensenews.com/story.ph ... &C=america

Whiteman_B2 wrote:

I just now read the article Lieven provided. I did not know that RR was involved in the F135 at all. That seems kind of strange to me. I mean, weren't they developing a competing design (F136)? Also, I don't see what Tony Blair is so upset about. It seems that the UK is still going to have a stake in the F-35.

Rolls are not directly involved with the F-135 engine. RR will supply the Lift Fan, roll posts/ducts and swivel exhaust nozzle for the STOVL JSF. This has always been the case. They will operate as a sub-contractor to Pratt. It does state this in the article. There must have been close co-operation between Pratt and RR to build components for the core F-135 unit to enable RR to develop it`s parts successfully. All Pratt needed to do was tell Rolls what they wanted, then Rolls would simply supply it. Now, how much Rolls needed to know about the F-135 in detail to make the lift systems work with the F-135 is open to debate....

Yes, RR were also developing a rival engine with GE. If Pratt wanted the best vertical take-off experts, then look no further than RR. This experience goes back to the 1950s. It looks like this was also part of the original JSF deal, with the UK as level 1 partners.
Tony Blair is upset because the F-136 could have made RR a lot of money. There is nothing wrong in my book with TB protecting British business interests. I would expect George Bush to do the same!

Now, JL, there could be life in the dog yet..(F-136). I don`t know how powerful the US advocates of the F-136 are. I guess GE have some pretty powerful friends. Here is a more on the same theme...

http://www.flightglobal.com/Articles/20 ... e+for.html

Sorry, but I can't let go of this one.

In regards to Pratt & R.R. verses best vertical take off Pratt's thrust to weight conversion, especially for T.B.'s Harriers, is no competition for G.E.'s F-136 version of any JSF's as far as thrust. Unless I'm way off base the one lacking element with the instability of the Harriers is exactly that which G.E. is offering, plenty of thurst.

All do respect.
jr1947

By the way, has anyone heard if there's been a definitive vote as to the subject of the single/dual sourcing decision? I've been reading every-where trying to find out the final results. any info. would be appreciated.

Quote:

sorry, but I can't let go of this one. In regards to Pratt & R.R. verses best vertical take off Pratt's thrust to
weight conversion, especiaaly for T.B.'s Harriers, is no competition for G.E.'s F-136 version of any JSF's as far
as thrust

What thrust are you claiming for the F136 that makes it better than the P&W F135? Where do you get these figures?

Quote:

by the way, has anyone heard if there's been a definitive vote as to the subject of the single/dual sourcing
decision.

At this time the governments are not paying for development of the F136. GE & RR signed an agreement to develop it themselves. JL raleigh NC

Hello Mastiff, As far as figures are concerned let me just leave it at that G.E. has," for the most part", allways been on top when it came to their,"G.E"'s version of thrust to weiight conversion over Pratt. As It's been indicated in the past certain subjects are sensitive as to what iformation should or shouldn't be allowed on this web site for individuals to monitor. What i will say is that the develoment of the f-136 in regards to G.E.'s/R.R. partnership the instibility of the Harriers verticall landing, with G.E. powerplants will no longer be an issue of concern for the piolts who fly them, provided they stick with dual sourcing, an use the f-136 version for the Harrier airframes. Unfortunately, I'm not at liberty to continue this subject any further at this time.

I understand completely that it's G.E.'s & R.R.'s develoment $'s going into this but if congress decides to return to single sourcing, using one powerplant supplier for the J.S.F. program than G.E.'s future in regards to the military end of the business, according to G.E. spokesman, they will consider washing their hands of it and concentrate on strickly commercial. The vote was suppose to be ended Feb. 28th. by the house voting one way or the other. It's extremely important to me personally to receive the decision A.S.A.P. I've been on the computer, on the phone, and sending letters for the past couple weeks. For whatever reason this ones gone right to the line as far as decision making, or it's been one heck of a secret.

Isn't it imazing the more the tax $'s being spent the less the people want the tax payers to know where the $'s are going.

Regards jr1947

PS: Thank you for reply to my post it was a pleasure corresponding with you.

Quote:

Unfortunately, I'm not at liberty to continue this subject any further at this time.

I tend to go by the release by company or government information as to what I think can be talked about. That's also how we prove things when in a discussion. Untill I see something official from the government or GE/RR I don't personally accept that there is a difference in thrust ratings, P/W ratio etc. You use whatever meets your demands to make up your mind.Past news releases by RR like this http://www.wired.com/news/technology/0, ... 43,00.html don't really inspire me though. IOW, I smell bull$#!~

Both GE and RR have a lot of experience between them. I figure the f136 would be a good design, meeting the specs the project engineers have called for. P&W will also, but are much farther ahead in the process.It's my personal opinion that the government should save every penny they can and don't believe for one second this would drive GE out of the military engine business. Anyhow this is a combat aircraft, not a jobs program for GE or RR.

Quote:

Unfortunately, I'm not at liberty to continue this subject any further at this time.

When in doubt it's better to be safe than sorry.

Quote:

It's extremely important to me personally to receive the decision A.S.A.P.

Good luck jr1947. It was nice meeting you. JL Raleigh NC

Forum: F-35 Engine

The one engine provider issue - Causing some pain