09 August 2019

Twenty-two percent of US Air Force C-130 fleet remains grounded

by Pat Host

Approximately 22% of the US Air Force’s (USAF’s) Lockheed Martin C-130 Hercules medium transport/multirole aircraft fleet remains out of service after the air force announced a temporary removal of 123 aircraft after cracks were found during an inspection.

The USAF announced on 7 August that 123 of 450 aircraft were temporarily removed from service after atypical cracks were found on the lower center wing joint, or rainbow fitting, during programmed depot maintenance. An Air Mobility Command (AMC) spokesperson said on 9 August that 23 aircraft had been inspected and deemed fit to return to service.

The US Air Force is focusing on inspections of C-130H (pictured) and J-model aircraft after cracks in the rainbow fitting forced the service to ground 27% of its fleet. (IHS Markit/Jamie Hunter)

After the USAF discovered these cracks, AMC commander General Maryanne Miller directed an immediate time compliance technical order (TCTO) inspection in response to identify and correct any cracking to ensure airworthiness of these C-130 aircraft, the service said on 7 August. In accordance with the TCTO, in-depth visual and modified non-destructive inspections of the wing box are being conducted on affected C-130H and J-model aircraft that have not received the extended service life centre wing box and have greater than 15,000 equivalent flight hours.

If cracking is identified during the eight-hour inspections, a depot-level replacement of the rainbow fitting will be required. Aircraft that are inspected and determined to have no cracking will be immediately returned to service.

Approximately 22% of the US Air Force’s (USAF’s) Lockheed Martin C-130 Hercules medium transport/mul...

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