JSF Heat Woes Getting Fixed: Trautman

DoD Buzz ^ | 7/18/2010 | Colin CLark

[ErnstStavroBlofeld]

Changes are being made to the integrated power package (IPP) on the Marine’s F-35 that should limit heat damage to carrier decks and other surfaces, Lt. Gen. George Trautman, deputy commandant for aviation, told DoD Buzz in an exclusive interview one day before the start of the Farnborough Air Show. In addition, the heat buildup from the STOVL drive shaft will be addressed in LRIP 4, although negotiations on that are still underway so costs for that are not set yet.

“We have made the decision to adjust the IPP,” he said Sunday, reshaping the nozzle so that the enormous thrust comes out in an oval shape instead of the more highly focused circle now used. It takes a “slight adjustment” to the IPP. The oval “will resolve that problem for almost all surfaces,” he said.

Joint Program Office documents detailed concerns that the STOVL version of the F-35 was too hot and too noisy for carriers and too hot even for some asphalt surfaces.

An operational assessment of the JSF said that heat may force “severe F-35 operating restrictions and or costly facility upgrades, repairs or both.” The OT-IID report says “thermal management” will “increase the number of sorties required to prepare an operational unit for deployment during summer months” at most American bases. It rated basing as red: “unlikely to meet criteria — significant shortfall.”

[ErnstStavroBlofeld]

Ping

[Vroomfondel]

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[DemforBush]

“Joint Program Office documents detailed concerns that the STOVL version of the F-35 was too hot and too noisy for carriers and too hot even for some asphalt surfaces.”

I would assume that the JSF’s heat issues stem primarily from of a combination of the amount of thrust needed to meet the F-35B’s high “max take off weight” (more than twice the AV-8B Harrier’s) and the raw power generally put out by an engine powerful enough to take the JSF to supersonic speeds.

It *would* be interesting to know if other fixed wing STOVL aircraft (AV-8B, Yak-38) have had/have heat issues, at least to a lesser extent.

[valkyry1]

//other fixed wing STOVL aircraft (AV-8B, Yak-38) have had/have heat issues, at least to a lesser extent//

Since they all rely on turbine exhaust for the rear portion of the VL thrust the problem would have been there, although to a lessor extent because the Yak-38 used multiple engines and the AV-8B Harrier was a much lighter aircraft as you mentioned.

The Pratt & Whitney F135 is The World’s Most Powerful Fighter Engine ever, so it is only natural that in the vertical lift mode there might be issues with the heat of its exhaust impinging upon certain areas of the flight deck and/or the tarmac.

[cranked]

This program should have been ass-canned along time ago....turning into nothing but a problematic money blackhole. =.=

[Yo-Yo]

Another reason why the F-35B (and the MV-22B for that matter, it also has a deck heating problem,) is worse than the Harrier it replaces is because the F-35B's rear nozzle is much closer to the deck in the vertical mode than the Harrier rear turbine exhaust nozzles are, and the Harrier splits its turbine exhaust between two widely spaced nozzles, further dissapating the heat.

Example:

As I said earlier, the MV-22B has a similar deck heating/warping problem, again because the turbine exhaust is so close to the deck when in vertical mode. With the MV-22B, the problem is with extended idling. Both the F-35B and the AV-8B can move their nozzles while idling, limiting deck damage. The MV-22B must keep its nacelles vertical for the entire time. The Navy has developed a portable heat shield to place under the engine during extended idling periods

One possible solution with the F-35B is to create a heat insulated landing pad at the rear of the deck for the aircraft to land on, then move out of the way for the next aircraft.

[diogenes ghost]

"This program should have been ass-canned along time ago...."

Indeed....it's a pig-in-a-poke, and they'll never make silk purses outta those sow's ears.

[valkyry1]

//heat insulated landing pad at the rear of the deck for the aircraft to land on//

Thats probably what they will end up doing, or some lessor variation of that.

ps; I forgot about that the Harrier split the exhaust into to 2 streams, so that was another factor.

[magslinger]

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[DesScorp]

Before it’s over, the JSF will make the F-111 program look like a model for development by comparison.