Latest From F-35 Tests

JSF Jocks Posted by Guy Norris at 8/20/2010 12:50 PM CDT


U.S. Air Force test pilot Lt. Col. Hank “Hog” Griffiths believes he may have flown faster in an F-35 Joint Strike Fighter than anyone else.

Griffith says in June he took the F-35A to 583 KCAS (exceeding Mach 1.2). “I may be the first to fly this fast in the jet so far,” he muses. “The jet handles well, and she just wants to fly fast. It has a monster engine. It looks like an aircraft that’s built around an engine.”

Lessons learned from the F-22 test program are helping speed the F-35 say program leaders. (Lockheed Martin)

Griffiths, who is also 461st Flight Test Squadron Commander and F-35 Integrated Test Force (ITF) director at Edwards AFB, was the pilot of one of the two F-35As flown to the desert base in May for the start of developmental test and evaluation (DT&E). Griffith was accompanied by Lockheed Martin F-35 Chief Test Pilot Jon Beesley who flew the jets, known as AF-1 and AF-2, nonstop in the first multi-ship, long-range F-35 flight.

Not surprisingly, Griffith is clearly a huge fan of the CTOL version which he says is racking up test points three times faster than scheduled. By the time of my visit earlier this week, the two F-35As had completed 53 sorties and 536 unique test points. The plan called for the pair to have completed 17 sorties and 150 test points by now, meaning that progress is being achieved at roughly three times the expected rate.

But can this be sustained? Griffith believes the answer is yes, but cautions that the more complex testing of the radar and electronic warfare configured aircraft next year could pose more challenges to the rate. Lockheed Martin’s target for the overall ITF test rate is 12 flights per month per aircraft. “That’s really three times per week, but already with the reliability of AF-1 and AF-2 we can schedule a flight every day,” he says.


AF-1 and 2 are focused on flight sciences objectives, including envelope expansion, loads testing, flutter clearance and flying qualities. “Our objective by the end of 2010 is to clear the envelope to 40,000-ft, subsonic with 80% of the potential design limit load,” Griffith says. In June, initial supersonic testing for loads and flutter was completed to around Mach 1.2/580 KCAS and 39,000-ft. Air refueling clearance tests at 15,000-ft is also getting underway, work having already cleared the refueling envelope at 20,000-ft and 30,000-ft.

Even when loaded internally with two 2,000lb GBU-31 Joint Direct Attack Munitions and two AIM-120 AMRAAMs, Griffith says the sheer power of the Pratt & Whitney F135 is evident. “The engine has a lot of thrust. It’s been fun to outrun the F-16 (chase aircraft). They can’t keep up. If we go to full military power the F-16 has to go to afterburner to keep up.”

The current flight tests with weapons are for captive carriage purposes only, as actual weapons tests will come in later phases of the program next year following the arrival (later this year) of AF-3 and AF-4 – the first to come configured with block 0.5 missions systems software. In the meantime Griffith says captive carry tests of AIM-9X Sidewinder air-to-air missiles are likely before long. The overall task of the initial test fleet at Edwards includes development, test and evaluation of propulsion, aerial refueling, logistical support, weapons integration and flight-envelope expansion.

(Lockheed Martin)

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