OVER HALF of the US Air Force’s 157 F-16D Fighting Falcons were grounded recently due to the discovery of canopy sill longeron cracks found between the front and rear pilot seats. Their removal from flight status was announced yesterday, August 19, by US Air Force officials.
The cracks were discovered following an immediate action time compliance technical order (TCTO) to inspect all F-16Ds due to initial structural cracks that were discovered during post-mission flight inspections. Following the TCTO, individual F-16 units conducted inspections on the USAF’s 157 F-16Ds to ensure the structural integrity of the aircraft and pilot safety.
As of August 18, inspections on all 157 aircraft had been completed. This resulted in the discovery of cracks in 82 aircraft, while the remaining 75 F-16Ds have been returned to flight status. The other F-16 variants were not affected.
The USAF F-16 Systems Program Office and Lockheed Martin engineers are analysing the F-16 structure and developing repair procedures to allow aircraft with cracks to resume operations for a limited number of flight hours while analysis continues to find a permanent fix.
“As aircraft accumulate flight hours, cracks develop due to fatigue from sustained operations,” said Lt Col Steve Grotjohn, the deputy chief of the Weapon System Division. “Fortunately, we have a robust maintenance, inspection and structural integrity programme to discover and repair deficiencies as they occur.”
The USAF is working with its F-16D operational units to mitigate the impact on operations, training and readiness. Programmed flying training and F-16 pilot graduation impacts will depend on the number and timing of aircraft returned to service. Subject matter experts are considering multiple courses of action to mitigate these delays.
The USAF F-16D fleet, the two-seat variant of the F-16 primarily used for training, is on average 24 years old, with more than 5,500 hours of flight time. There are a total of 969 F-16s of all variants currently in the USAF inventory. AFD-Dave Allport