It's taken a bit longer than planned, but the first short take-off and vertical landing F-35B Joint Strike Fighter has fired up its engine. BAE Systems test pilot Graham Tomlinson was at the controls on April 18 for the first ground runs of the Pratt & Whitney F135 powerplant in aircraft BF-1. Lockheed Martin says the tests keep the F-35B on track to fly by late May/early June.
Opening doors - F-35B powers up. Photo: Lockheed Martin
It was touch and go for a while after third-stage low-pressure turbine blades in two STOVL engines failed on the test stand because of fatigue caused by high-frequency vibration. But P&W is certain the vibration only occurs at high power in STOVL mode, when the turbine is driving the lift fan. So this particular engine has been cleared for CTOL flying only while P&W fixes the problem. You can read more about the tests in Monday's Aerospace Daily.
I hope it works better than anticipated so far, because ideally ALL JSFs should be F-35Bs ;).
Hey Marcase, do you know anything about this tech having been bought from the Russians??? I keep hearing that story but haven't been able to nail it down...
Heard nothing about that, but the Russians did fiddle with their Yak-38 and Yak-141s which had similar conventional jet-engine/lift engine(s) combo, so probably some info was shared/bought/gathered about that.
While the Yak-38 was nothing more than a winged lawnmower, the Yak-141 was actually a reasonable VSTOL fighter, superior to the Harrier since -like JSF- it had a "real" jet-engine complete with afterburner.
Somewhere way back in the JSF program, I saw a LM JSF cockpit mockup which had a Russian type ejection seat, complete with dual cyrillic/Roman lettering. Whether that was an inhouse joke or an actual serious option was left in the middle. The Russian ejection seats were/are better than the good old ACES or Martin Bakers - mainly because Russian seats are used more often, as the joke goes.
F-35 approach for the front lift is very innovative and conceptually simple.
Aft lift is similar to YAK's.
F-35B is the most advanced piece of technology of the F-35 pack. Really a breakthrough.
Eager to see what will be the real stuff.
Interesting about the ejection seat. One of the worst cases in an F-35-type, or Yak-type STOVL configuration is a total failure of the front lift system (jet or engine-driven fan) in powered-lift mode, which causes the airplane to pitch violently nose down into an attitude at which ejection is impossible. The Russians decided that the pilot could not respond in time and incorporated an auto-eject mode into their aircraft.