### Re: F-35 internal fuel, range

Posted:

**31 Jul 2019, 13:41**spazsinbad wrote:OOoohh youse guys are hilarious. I'd reckon 'QS' has a good handle on it all. And it is goodnight from him - with ONE stent.

438 KTAS @ 32kft = Mach 0.75

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Posted: **31 Jul 2019, 13:41**

spazsinbad wrote:OOoohh youse guys are hilarious. I'd reckon 'QS' has a good handle on it all. And it is goodnight from him - with ONE stent.

438 KTAS @ 32kft = Mach 0.75

Posted: **01 Aug 2019, 01:38**

sprstdlyscottsmn wrote:320kt TAS is way too slow for tactical aircraft max range cruise. 320 is closer to the IAS.

Alt 30,000ft

320KTAS-----494KTAS

200KCAS-----320KCAS

0.543M-------0.838M

Alt 36,000ft

320KTAS-----541KTAS

180KCAS-----320KCAS

0.558M-------0.943M

Alt 40,000ft

320KTAS-----585KTAS

164KCAS-----320KCAS

0.558M-------1.020M

Best LOITER was given as 32,000ft, 0.75M (438KTAS, 271KCAS), with about 4,600pph in the F-35A with this stated to give a total of 4 hours of fuel. Obviously you don't get to use all 18,400lb of fuel in loiter but as you get lighter you burn less fuel and go up in altitude.

Absolutely agreed. The question is whether its theoretically possible for the C to have 2.5 hrs (or close to) TOS. Of course it can with the assumptions of higher altitudes with a very low loiter speed for max end. The assumption of 320 kts is of course valid for the question. As already mentioned, its not going to happen in actual ops but that's not the question here.

sprstdlyscottsmn wrote:Also, you are using an F-35B chart to infer information about the F-35C. Their climb/cruise/descent profiles will be vastly different due to the wing. Even so, the 1,304nm you are assuming for cruise would be closer to 2.4hr endurance using 320KCAS at 36,000ft.

No other publicly available chart available. All 3 variants are using the same engine so fuel use rates should roughly be about the same. Agreed wing affects climb and descent rates but difference on range won't be materially far off.

What I like about the chart is it explains the fuel burn rate is based on a training profile for a sortie (minus actual ops). So theoretical max endurance fuel burn rates will probably be a slightly lower consumption figure.

Posted: **01 Aug 2019, 01:49**

Anyway you look at it the F-35 has exceptional range for a Tactical Fighter. This will only improve with time. As they're developing even more fuel efficient engines. Including newer models of the F135 plus the ACE Engines. (XA100 and XA101)

Plus, external Fuel Tanks and CFT's.

Plus, external Fuel Tanks and CFT's.

Posted: **01 Aug 2019, 03:45**

I tend to think CAP distances will grow beyond the outer defense zone mean of 200 nm

and more towards 300+ nm by virtue of the fact that the escort AAW weapons are no

longer horizon limited and are much, much longer ranged e.g. SM-6 Block IB.

and more towards 300+ nm by virtue of the fact that the escort AAW weapons are no

longer horizon limited and are much, much longer ranged e.g. SM-6 Block IB.

Posted: **01 Aug 2019, 23:04**

“The question is whether its theoretically possible for the C to have 2.5 hrs (or close to) TOS. Of course it can with the assumptions of higher altitudes with a very low loiter speed for max end.”

Actually, the question was 2.5hrs at what distance from the launch point. We have to assume a TAS icw the #/nm number; assuming 8.5nm/minute (510KTAS) that’s ~96#/min or -5700#/hr. That’s 11.4K# just from to/from ~500nm, leaving 3.3K to burn on station.

If we go to 400nm, we get another ~2K to burn on station, or 5.5K total (1.2hrs).

If we go to 300nm, we get a total of roughly 8K to burn on station (or 1.7hrs).

Actually, the question was 2.5hrs at what distance from the launch point. We have to assume a TAS icw the #/nm number; assuming 8.5nm/minute (510KTAS) that’s ~96#/min or -5700#/hr. That’s 11.4K# just from to/from ~500nm, leaving 3.3K to burn on station.

If we go to 400nm, we get another ~2K to burn on station, or 5.5K total (1.2hrs).

If we go to 300nm, we get a total of roughly 8K to burn on station (or 1.7hrs).

Posted: **10 Aug 2019, 09:58**

Greg Ulmer says the F-35 has the best Range of the 4th or 5th gen fighters. Best...!! (Get bigger and bigger...! )

Greg Ulmer, vice president and general manager of the F-35 Ligthning II fighter program at Lockheed Martin.

From RIAT 2019 @1:00~

A lot of people talk about the range and payload for the airplane.

The airplane performs exceedingly well in terms of range.

Probably, it has some of the best range in terms of even 4th or 5th gen aircraft.