The Air Force has grounded 82 of its two-seat F-16D Fighting Falcons due to structural cracks discovered on the canopy sill between the front and rear pilot seats. Cracks found on one aircraft during a routine post-flight check led to an immediate action time compliance technical order to inspect all 157 F-16Ds. The inspections found cracks in the canopy sill longeron in 82 aircraft. The remaining 75 D models were restored to flight status as of Aug. 18. Air Force F-16 Systems Program Office and Lockheed Martin engineers are analyzing the F-16 structures and developing repair procedures to allow a limited return to flight by the affected aircraft until a permanent fix can be made. “As aircraft accumulate flight hours, cracks develop due to fatigue from sustained operations,” Lt. Col. Steve Grotjohn, deputy chief of the Weapon Systems Division, said in an Air Force release. “Fortunately, we have a robust maintenance, inspection, and structural integrity program to discover and repair deficiencies as they occur.” The F-16Ds are used primarily for flight training by Air Education and Training Command and the Air National Guard. Air Force officials are working with the operational units to mitigate the impact of the grounding.
The Air Force overall reduced its size by 120 aircraft in fiscal year 2021, but kept about the same number of fighter, bomber and attack aircraft, according to data supplied by the service. The F-35 fleet saw the biggest increase while the B-1B bomber fleet saw the largest decline.