The US Air Force has grounded 127 Fairchild Republic A-10s that require immedate inspection and repairs for wing cracks, which the service calls a "systemic problem" for an aging fleet.
The USAF operates a total of about 360 A-10s, of which the oldest roughly 240 were manufactured with "thin-skin" wings. All of the grounded aircraft come from the thin-wing fleet.
The affected aircraft are grounded until they can be inspected and any repairs made, a US Air Force spokesman says. The first priority for inspections are A-10s based in US Central Command, which includes Iraq and Afghanistan, where the close air support asset is in heavy demand.
It was not immediately clear how long it would take for the entire fleet to be inspected.
The A-10 first entered service in 1977, and is now the target of several modernization programs.
In June 2007, the USAF awarded Boeing a $2 billion contract to replace the wing sets for all A-10s with thin-skin wings.
The USAF's tactical air fleet is showing increasing signs of brittleness as the average age rises well over two decades. The A-10s were originally expected to be replaced by the Lockheed Martin F-35A, but are now being counted on to remain in service for at least 20 more years.
Last November, the USAF also grounded all Boeing F-15s after one fighter disintegrated during flight on 2 November. That issue was traced to longeron cracks caused by shoddy manufacturing, but was limited to affecting only nine remaining aircraft across the fleet.