F-35 internal fuel, range

[alloycowboy]

Also don't foget that the F-35's are going to get 600 gallon drop tanks eventually which means an extra 8000 lbs of fuel.

So that would push the F-35C's fuel capacity to 19840 lbs (internal) + 8000 (external)= 27840 lbs

The F-15's Conformal Tank carry 849 gallons.

[element1loop]

The range is impressive especially with MQ-25A AAR. I'd like to know the altitude performance difference the larger wing produces compared to F-35A.

Fairly clear an F-35 version with a three-stream adaptive cycle engine and the C's wing will be able to operate to 1,000 nm radius from a carrier.

[Gums]

Salute!

Any of you that have flown an attack or interceptor in combat or U.S. training must be happy that the new F-35 has such good legs.

This new plane is a delight. You know where you are. You know about the "threat" SAM sites within a hundred miles or so. You have great escape capability if the mission goes south and you have to get outta Dodge.

Glad to see such range numbers with basic internal fuel.

Gums sends..

[Corsair1963]

The range is impressive especially with MQ-25A AAR. I'd like to know the altitude performance difference the larger wing produces compared to F-35A.

Fairly clear an F-35 version with a three-stream adaptive cycle engine and the C's wing will be able to operate to 1,000 nm radius from a carrier.

Honestly, I wouldn't be surprised to see an ACE equipped F-35C (or whatever they call it) post 2030. These would replace the remaining Super Hornets. Then when the NGAD comes on line. It in turn would start to replace the early production F-35C's.

[energo]

I was looking around the forum for a suitable thread to post this, so forgive me if this is a bit off topic. Attached is a Wingtips pdf with a great article on the F-16's background and first hand anecdotes from F-16 pilot Terry Lutz.

What caught my attention was this story, which elaborates on the story mentioned in the Boyd biography that the F-16, to the surprise and dismay of the USAF generals, had longer legs than the F-15A:

The Generals in Washington remained skeptical of the F-16.
They could not believe a small, light weight airplane had
greater range than a larger, twin engine design. Yes, a
larger airplane has more internal volume for fuel, but the
larger airplane weighs more, has more drag, and needs more
power to push all that drag.

To prove the point, the F-16 Combined Test Force Director,
Col Jim Rider, flew one of the prototypes with two external
fuel tanks non-stop from Edwards AFB in California to
Andrews AFB in Maryland, without air-to-air refueling. As
it happened, I had flown into Andrews on my one flight a
month in the T-39, and was headed back to Wright-
Patterson. In the climb passing about 12,000 feet, 20 miles
or so west of Washington Dulles Airport, I spotted an F-16
descending in the opposite direction (*recall the range). It
was rather incredible to be in the air at the same time, and
pass within range of a visual tally on Jim Rider, quietly
making fighter aviation history.

For the record, the straight line distance from Edwards to Andrews is about 1,960 NM (3,630 KM).

[johnwill]

Bjornar, thanks for posting this piece. Very interesting. I was at Edwards then, and we followed that flight all the way with radio updates. It was personal for me, because he was flying my flight loads test airplane (F-16A No. 2). It was heavily instrumented to measure loads distributed all over the airplane. It was irreplaceable in my mind. That's the same airplane that did icy runway tests at Bodo.

Hope all is well with you. We are still hanging in there.

John

[sprstdlyscottsmn]

Would that have been 600s under the wings and the 300 Centerline?

[steve2267]

I read it literally -- two wing tanks, and no centerline tank. Didn't the centerline tank come later?

[johnwill]

Would that have been 600s under the wings and the 300 Centerline?

No, it was the standard 370s at 4 and 6, AIM-9s at 1 and 9. 600s on weapon pylons were cleared a few years later for Israel and even later for some others.

[johnwill]

I read it literally -- two wing tanks, and no centerline tank. Didn't the centerline tank come later?

Centerline tank was cleared later in FSD testing. For that flight, speed and g limits were restricted since full limits for the 370s had not been cleared.

[steve2267]

Reading between the lines... sounds like they cut it kind of close, esp. if JW was on pins-and-needles, irreplaceable and all that.

Guessing a 0.8M cruise, and landing with 1000lb... that puts F-16A cruise fuel burn around 2600lb/hr (Gums oughta know). Scaling on thrust, that suggests 4800lb/hr for cruise burn for the Panther. All sound in the ballpark from what I've heard from Spurts in the past.

[johnwill]

Irreplaceable because of thousands of man hours and millions of 1977 dollars invested in the load instrumentation. I designed much of it, monitored its installation, planned and executed its calibration, checkout, and maintenance during the flight tests. Another airplane had backup instrumentation installed, but not connected or calibrated. Several months delay would result if it had been necessary to activate it.

[steve2267]

Irreplaceable because of thousands of man hours and millions of 1977 dollars invested in the load instrumentation. I designed much of it, monitored its installation, planned and executed its calibration, checkout, and maintenance during the flight tests. Another airplane had backup instrumentation installed, but not connected or calibrated. Several months delay would result if it had been necessary to activate it.

Oh, I get that part, and thanks for expounding on it with more detail. But it sounds like they may have cut it a bit close on fuel for this PR stunt, err, demonstration?

[steve2267]

I stand to be corrected. I found this post by Gums a little ways back in this thread:

...

This new guy looks fantastic, with more gas internal than the law should allow. I would like us to have a F-35 driver tell us the fuel flow at normal cruise and 25,000 to 30,000 feet. The Sluf and Viper were about the same, with Viper maybe a bit better. On RTB we both burned about 1,500 lb/hr at .8M and 30,000 feet. I cannot recall our burn going in, but it was much higher.

...

With only two 'winders and a pair of 370gal tanks, the cross-country F-16A magical loads vehicle woulda been similar to a Viper returning home. Maybe gas burn is higher than 1500lb/hr at first cuz of the extra weight, but this would have put total fuel burn on the order of 7k lb, so another 5k in reserve? So maybe not as tight on gas as I had guessed. Which makes sense -- you'd hate to lose your loads test aircraft because of (or during) a PR demo.

Scaling on thrust again, and neglecting increased thermodynamic and aerodynamic efficiencies, such a fuel burn suggests the F135 burns around 2700lb/hr in RTB cruise. Do you buy that Spurts?

[sprstdlyscottsmn]

Would that have been 600s under the wings and the 300 Centerline?

No, it was the standard 370s at 4 and 6, AIM-9s at 1 and 9. 600s on weapon pylons were cleared a few years later for Israel and even later for some others.

That is impressive. Thanks for the correction johnwill.