Tuesday, September 25, 2012

New engine for the F-35 by 2020?

That's the plan:
It has been almost three decades since the U.S. last set out to develop an all-new combat-aircraft engine, but more than 50 years since the turbojet gave way to the turbofan. Now the U.S. is embarking on development of a new generation of fighter engine with an architecture it considers as fundamental an advance as the turbofan was over the turbojet.

Being part of a research effort that could produce the dominant combat-aircraft engine of coming decades is critical for industry. So General Electric and Pratt & Whitney are breathing easier after being selected by the U.S. Air Force Research Laboratory (AFRL) for the Adaptive Engine Technology Development (AETD) program to mature fuel-efficient, high-thrust powerplants for post-2020 upgrades to the Lockheed Martin F-35 and future “sixth-generation” combat aircraft. 
The new engine will combine fuel efficiency and increased power:
AFRL calculates adaptive technology will improve engine fuel efficiency by 25% over the F135 powering the F-35, increasing aircraft combat radius by 25-30% and persistence by 30-40%. The engine could also help address the anti-access/area-denial challenges posed by a potential conflict with an near-peer adversary such as China, says AFRL. This could be achieved via increasing supersonic-cruise radius by 50% and reducing the aerial-refueling tanker burden by 30-74%.

Under the 48-month AETD program, GE and Pratt will design engines with 25% lower SFC, but 5% more military (dry) power and 10% higher maximum (reheat) thrust than the F135. “We will take that engine through preliminary design review,” says Reed. The engine must be sized to fit the F-35 with “only modest modifications,” he says. 
An ambitious but achievable program.  And one which will make criticism of the F-35's combat radius, etc. moot (most are presently ill-informed as it is).



  1. Interestingly, this technology often gets brought up as a reason supersonic bombers should now be pursued more aggressively. Yet the most benefits are from how the supersonic propulsion system is essentially 'tuned' to have higher efficiencies in the subsonic regime than otherwise. The dual-optimization allows the supersonic configuration to be optimized a little more towards the supersonic dash and the subsonic configuration allows much better efficiency when flying slower.
    People forget that in the ATF competition, there was an engine competition going on as well. As Paul Metz noted (AIAA-92-1039)"The P&W powered YF-23A achieved a standard day super-cruise speed of [M]1.43 while the GE powered YF-23 achieved a higher top speed which remains classified." We could have had this technology fielded already. Had the The GE engine been selected, the F-22 might not have had thrust vectoring, but it would have been much longer ranged AND faster. What we have fielded in the F-22 was the then perceived 'lower-risk' vs. 'most capable' course of action.

  2. Well. F-35 needs another engine. the existing engine simply does not give the aircraft good enough acceleration, topspeed and range.