posted on Jan, 14 2013 @ 10:37 PM
The F-35 program suffered a pretty significant setback, with the Pentagon lowering the standards for the aircraft. The standards for transonic
acceleration, and sustained G loading have been reduced, pretty significantly in the A and B aircraft, but in all three models. Flight testing during
2012 had been going well for awhile, with several significant goals being met, including weapons release goals.
The G load for the A has been reduced from 5.3Gs to 4.6Gs. The B goes from 5Gs to 4.5Gs, and the C from 5.1 to 5.0Gs. The acceleration for the A
added 8 seconds for acceleration from Mach 0.8 to Mach 1.2. The B added 16 seconds, and the C added a whopping 43 seconds.
This is on top of the horizontal tails suffering delamination and scorching during high speed/high altitude flight. The B and C are also suffering
transonic roll-off and buffeting issues, the C more than the B due to the wing area.
Probably the biggest news was that the fatigue testing airframe had to stop testing in December due to cracking found in the bulkhead flange on the
underside of the fuselage during the 7,000 hour check.
The US Department of Defense is lowering the performance bar for the Lockheed Martin F-35 Joint Strike Fighter according to a new report by the
Pentagon's director of operational test and evaluation (DOT&E).
The specifications for all three variants pertaining to transonic acceleration and sustained turn rates have been reduced. Worst hit in terms of
acceleration is the US Navy's F-35C carrier-based model.
"The program announced an intention to change performance specifications for the F-35C, reducing turn performance from 5.1 to 5.0 sustained g's and
increasing the time for acceleration from 0.8 Mach to 1.2 Mach by at least 43 seconds," reads the report prepared by J Michael Gilmore, the
Pentagon's DOT&E. "These changes were due to the results of air vehicle performance and flying qualities evaluations."
The US Air Force F-35A's time has slipped by eight seconds while the US Marine Corps short take-off vertical landing (STOVL) F-35B's time has
slipped by 16 seconds. However, turn rates for both the A and B models have been impacted more severely than the USN variant. Sustained turning
performance for the F-35B is being reduced from 5G to 4.5G while the F-35A sinks from 5.3G to 4.6G according to the report.