"Due to inadequate leadership and management on the part of both the Program Office and the contractor, the program has failed to develop..?
http://aviationweek.com/site-files/a...l%20Report.pdf
"The following details discoveries in F-35A flight sciences testing:
- Testing to characterize the thermal environment of the weapons bays demonstrated that temperatures become excessive during ground operations in high ambient temperature conditions and in-flight under conditions of high speed and at altitudes below 25,000 feet. As a result, during ground operations, fleet pilots are restricted from keeping the weapons bay doors closed for more than 10 cumulative minutes prior to take-off when internal stores are loaded and the outside air temperature is above 90 degrees Fahrenheit. In flight, the 10-minute restriction also applies when flying at airspeeds equal to or greater than 500 knots at altitudes below 5,000 feet; 550 knots at altitudes between 5,000 and 15,000 feet; and 600 knots at altitudes between 15,000 and 25,000 feet. Above 25,000 feet, there are no restrictions associated with the weapons bay doors being closed, regardless of temperature. The time limits can be reset by flying 10 minutes outside of the restricted conditions (i.e., slower or at higher altitudes). This will require pilots to develop tactics to work around the restricted envelope; however, threat and/or weather conditions may make completing the mission difficult or impossible using the work around.
- Testing to characterize the vibrational and acoustic environment of the weapons bays demonstrated that stresses induced by the environment were out of the flight qualification parameters for both the AIM-120 missile and the flight termination system (telemetry unit attached to the missile body required to satisfy range safety requirements for terminating a live missile in a flight test). This resulted in reduced service life of the missile and potential failure of the telemetered missile termination system required for range safety."
of course there may well be NO evidence of B model overheating as the testing for this variant may have been ****canned either due to being another inconvenient truth or they just never got round to it ...