US Air Force Boeing F-15A-Ds are to remain grounded, even after structural inspections are completed, until investigation of the November crash is complete and a solution to fuselage longeron cracking is developed.
The F-15s had been returning to flight after undergoing inspections, called time compliance technical orders (TCTO), but on 3 December the head of USAF Air Combat Command, Gen John Corley, ordered the aircraft to remain grounded.
ACC says the decision followed a briefing on the investigation into the 2 November crash of a Missouri Air National Guard F-15C following structural failure, in which investigators reported they had found additional longeron cracking in the mishap aircraft.
Longeron cracks were found in the area of the cockpit sill
(from Flight cutaway of the F-15A)
Since ordering inspection of all F-15A-Ds, the USAF has found longeron cracks in two aircraft operated by the Oregon Air National Guard. Both were built in the early 1980s, and are about the same age as the Missouri mishap aircraft, says ACC.
Additional TCTOs were ordered on 29 November and so far more than 195 of the USAF’s 445 F-15A-Ds have undergone these inspections, says the command. “The TCTOs are still out there, and aircraft will still undergo inspection, but even if they pass they will not fly,” says ACC.
The command does not know whether the solution to the cracking problem will be “a repair, more TCTOs or what, and we are not putting a date to it.”
Grounding of the F-15s continues to be used by US Air Force leadership to underline its need for additional funding to continue procurement of the Lockheed Martin F-22A beyond the planned 183 aircraft.