In this article:
The Pratt & Whitney F135 engine
The Pratt & Whitney F135 engine (that powers all three variants of the F-35 Lightning II fighter aircraft) evolved from the company F119 engine that powers the F-22 Raptor and builds upon decades of combat-proven propulsion experience.
With more than 40,000 lbs. of thrust, unmatched low-observable signature, world-class thermal management, and the most advanced integrated engine control system ever created, the F135 engine is the heartbeat of the F-35.
The F135 is the most powerful and most advanced fighter engine ever produced and delivers unrivaled performance to the warfighter, enabling operations in the most advanced threat environments.
Is the F135 better than the F119?
‘A simple glance at engine specs looks like this:
The F119-PW-100 (F-22) offers the following:
- 26,000 lbf (116 kN) Dry
- 35,000 lbf (156 kN) Wet (w/ afterburner)
- Weight: 3,900 lb (1,769 kg)
- Thrust-to-weight ratio: 6.7:1/9.0:1(afterburner)
The F135-PW-100 (F-35) offers the following:
- 28,000 lbf (125 kN) Dry
- 43,000 lbf (191 kN) Wet (w/ afterburner)
- Weight: 3,750 lb (1,700 kg)
- Thrust-to-weight ratio: 7.47:1/11.47:1(afterburner)
‘Additionally, the F135 will be getting an upgrade (ECU) which will improve range, thrust, thermal management to support the Block 4 upgrades for the F-35.’
The F119 allows the F-22 to exceed Mach 2.2
The F135 proves superior to the F119 but not in every category.
According to another interesting comment appeared on Quora in fact, ‘the larger the engine diameter, the lower the airspeed where the compressor Mach throttles. That’s why the F135 tops out at Mach 1.6. It’s not thrust:drag-limited, the compressor blade tips break the sound barrier at that speed. And the air itself, the shocks between the blades, starts to form a restrictor plate over the compressor face. The smaller diameter of the F119 allows the F-22 to exceed Mach 2.2 before that happens. I expect the F-22 is not thrust:drag-limited for top speed either. It has more thrust than the SR-71, and is a smaller and (based on its acceleration) slippier design, so on thrust:drag alone it should be faster than the SR-71. While the primary limit of Mach 2.2 is due to the limit of allowable skin heating before the RAM coating gets damaged, I doubt it can go over Mach 3 even not considering the RAM.’
Photo credit: Pratt & Whitney and Rick Goodfriend/U.S. Air Force