Forum: F-35 Lightning II

From what I hear Teg is the "engine guy" to ask. I guess I'll take his word on this one. He sounds like he knows more than me.
Cheers

Teg

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longrifleman wrote:

From what I hear Teg is the "engine guy" to ask. I guess I'll take his word on this one. He sounds like he knows more than me.
Cheers

Teg

The impression I got, was that it was 20% over 43k, seeing as how it was a response to GE's claim of 15% over. The also mentioned 50k+ thrust in the article.

wrightwing wrote:

The impression I got, was that it was 20% over 43k, seeing as how it was a response to GE's claim of 15% over. The also mentioned 50k+ thrust in the article.

Perhaps during a test on a stand; but not installed in an aircraft in flight condition.

Think of the F110s that were put into the small-mouth Vipers, not as much power as the same engine placed in the big-mouth Vipers. The difference was the inlet. On a thrust bed I'm sure both engines would measure the same thrust, but installed one would be significantly less than the other.

If PW is saying the 'system' will only take 43K thrust MAX, it is due to inlet/exhaust restrictions. The airframe is only designed/built for 43K of thrust.

Just because PW made more during a test, or GE made more during a test, doesn't mean that will translate into the current production F-35 aircraft.

One could reprogram/tweak the current F100 or F110 engines to make more than 29K, but the engine's durability (TBO) would suffer. It would also increase fuel consumption, and put further strain/age on airframes.

What it DOES indicate, is the engines can make more power if needed at a future date for later production aircraft; IF that power is needed, and IF the airframe is modified for it. (IE larger inlets and/or exhaust.)

Yes, some of PW and GE's tests did go well over the 43K specified; but it's highly unlikely any of the F-35A/B/C will see the 'tested' thrust margins. Perhaps the F-35D/E/F with the F135-PW-152?

Who knows, might even help get a new version Raptor with more powerful motors too?

TEG

Of course, another quote from that article that hasn't been included so far is:

""The value of the GE-Rolls Royce thrust margin over specification is that it allows the engine to operate at the current spec, but at much lower operating temperatures in the core,"...""That's the whole point. This provides a considerable advantage in durability and operating costs."

Although there hasn't been that much recently about it, earlier in the decade it was being briefed that the ultimate thrust the F136 in this iteration was being designed around was 56K, to accommodate growth applications. As TEG points out, Warren Boley, Pratt's director of military engines, notes that the F-35's afterburner and nozzles would require redesign to accept more than 43K from either engine. On the other hand, GE points out that their engine can take advantage of the 2005 F-35 intake redesign that increased inlet size to improve core airflow by 10%

The article also goes on, "Boley and Croswell's statements notwithstanding, Pratt is developing a next-generation F135 engine core that can provide more thrust or better fuel efficiency".

wrightwing wrote:

longrifleman wrote:

From what I hear Teg is the "engine guy" to ask. I guess I'll take his word on this one. He sounds like he knows more than me.
Cheers

Teg

The impression I got, was that it was 20% over 43k, seeing as how it was a response to GE's claim of 15% over. The also mentioned 50k+ thrust in the article.

I think the same. I hear the limit is the exhaust and P&W built that too with "margin". The intakes were inlarged years ago for this reason. The F-35B has TV exhaust and was made by RR. It has a lower thrust limit. That 20% margin in the test was within the 400 q/f/s airflow limit of the F-35A and C intakes. Do to the lift fan the B flows a little less air. Mosty at high speed. The mach 1.6 spec for the F-35 is the min. for the B modal. The A and C should be a little faster and have a little most installed thrust.

Also, I have been reading the forums on F-16.net for years and respect TEGs info. I've learned much from Teg over the years. I would listen to him on most things. If nothing else... engines.

Progress To Date:
F135 Production Engines Delivered: 33
F135 Powered Flights: 1406
F135 Flight Hours: 2130
VERTICAL LANDINGS: 267

www.f135engine.com

enginesrus wrote:

[b]Progress To Date:
F135 Production Engines Delivered: 33...

Great!

That will power all thru LRIP-2 with 6 spares

That can put 6 F-35A and 6 F-35B at Eglin for training. Smile

Nearly 20% of the total flights ended with vertical landings.
That'll cheer up BS Laughing

enginesrus wrote:

[b]Progress To Date:
F135 Production Engines Delivered: 33 ...

With 80+ engines ordered thru LRIP 4 and 33 delivered Smile

, for SDD+LRIP 1+LRIP 2, how many spares Idea

have been delivered (of the 33) and has the contract been let for the 30 engines for LRIP 5 Question

?

Forum: F-35 Lightning II

F135 Propulsion Status