Aviation Week’s Bill Sweetman had posted a blog on the current status, hurtles, and key major issues in the testing phase for the Joint Strike fighter and its goal to enter initial operational testing in 2015. He has read and reviewed the Pentagon Quick Look Review and give his thoughts on some of the key issues. Some of the finding s were:
-After several sorties above Mach 1.6 there was “peeling and bubbling” of coatings on the horizontal tails and damage to engine thermal panels, the entire test force was subsequently limited to Mach 1.0.
-High level of airframe fatigue issues has been found on the testing aircraft.
-Pilots helmet-mounted display issues is in latency: the image in the helmet lags 130 milliseconds behind sightline movement where the spec is under 40 ms. (So the video is where the pilot’s head was pointed an eighth of a second ago.) That can’t be fixed without changing the JSF’s integrated core processor – the jet’s central brain – and the EO-DAS sensors. Even the backup helmet faces buffet and latency issues, simply for symbology.
-The underwing fuel dump system on the JSF doesn’t get fuel clear of the aircraft surfaces, so that fuel accumulates in the flaperon and may get into the integrated power package (IPP) exhaust. That creates a fire hazard, particularly on a ship deck after landing. Fuel dumping has been banned except in an emergency. Two unsuccessful modifications have been tried on the F-35B.
-failure” caused IPP parts to puncture a fuel tank – is turning out to be unreliable. It’s supposed to last 2,200 hours, but so far in the flight test program, 16 IPPs have been removed and replaced – a process that takes two days of 24-hour work.
-The arrester hook issue has been reported. In the first round of tests, the hook failed to catch the wire once. The QLR notes that tests of a minimal modification – a reprofiled hook with different damper settings. Studies are already underway of changing the hook’s location – the basic problem is that the designers put the hook closer behind the main landing gear than that of any current or recent Navy aircraft so hard for pilots to get use to the new landing envelope.
-flight tests have not gone beyond 20 degrees angle of attack, and higher-than-predicted buffet loads have been experienced when the JSF is in a high AOA
-Some negative Stealth and Thermal issues has arisen and also need to be addressed.
Read more at:
Bill Sweetman original Blog: Ares A Defense Technology Blog
Pogo Link to the Original copy of the Quick look report:http://www.pogo.org/resources/national-security/f-35-jsf-concurrency-quick-look-review-20111129.html