Courtesy of defense-aerospace.com, I’ve just had sight of what seems to be an about-to-be-released official US Government report that is absolutely excoriating about the current progress of the F-35 - all versions. It’s Michael Gilmore’s annual report - he’s Undersecretary at the Pentagon for Operational Test & Evaluation, OT&E.
Here are a few bullet points. (mostly my bold)
F-35 doesn’t meet the Operational Requirements Document (ORD) requirement to have a vulnerability posture better than analogous legacy aircraft. This refers to the removal of “fueldraulic fuses, the PAO shutoff valve, and the dry bay fire suppression” as part of a weight-reduction program.
For the F-35A, changing performance specs to reduce “turn performance from 5.3 to 4.6 sustained Gs and extending the time for acceleration from 0.8 Mach to 1.2 Mach by 8 seconds.”
For the F-35B, changing performance specs to reduce “turn performance from 5.0 to 4.5 sustained Gs and extending the time for acceleration from 0.8 Mach to 1.2 Mach by 8 seconds.”
For the F-35C, changing performance specs to reduce “turn performance from 5.1 to 5.0 sustained Gs and extending the time for acceleration from 0.8 Mach to 1.2 Mach by
at least 43 seconds.”
For both A & B,
“delamination and scorching of the [horizontal tail] surface coatings and structure.” because of unexpected high temperatures in sustained high-speed, high-altitude flight.
In the F-35C, “
transonic buffet becomes severe in different portions of the flight envelope and is more severe in the F-35C than the other variants.”
In the F-35B, the program halted testing in December 2012 after
multiple cracks were found in a bulkhead flangeon the underside of the fuselage during the 7,000-hour inspection. Root cause analysis, correlation to previous model predictions, and corrective action planning were ongoing at the time of this report
Other cracks were previously discovered in the B-model test article; one on the right side of the fuselage support frame in February and one at a wing pylon station in August, both of which were predicted by modeling. Another crack in the shear web tab that attaches to the support frame was discovered in March.
Also, excessive wear was found on the nose landing gear retractor actuator lugs and weapons bay door hinges.
All of these discoveries will require mitigation plans and may include redesigning parts and additional weight.
In a live ballistic fire test, a ruptured line containing flammable PAO avionics coolant caused a sustained fire with a leak rate of 2.2 gallons per minute (gpm). The program assessed that
a similar event in flight would likely cause an immediate incapacitation and loss of the pilot and aircraft.
The defense-aerospace report, which contains a link to the original 43-page OT&E document. is at
OT&E Reports New F-35 Problems
Scary stuff, even though we have heard of some of these things before. This appears to put an official seal on them.
airsound