Air Force grounds KC-135 fleet over tail pin concerns

By Michael Marrow / February 15, 2023 at 4:01 PM

The Air Force has grounded its fleet of KC-135 air refueling tankers over concerns that a faulty connecting piece could cause an aircraft’s tail to fall off during flight, the service announced in a press release.

“Vertical terminal fitting pins,” as they are called, connect the aircraft’s tail to its body, which the Air Force fears could have been incorrectly installed. The grounding order extends to all KC-135s as well as the reconnaissance variant RC-135 and the WC-135 used for atmospheric collection and analysis.

"We're taking this action out of an abundance of caution, after consulting with our engineering experts," Col. Michael Kovalchek, senior materiel leader with the Air Force Life Cycle Management Center's Legacy Tanker Division, said in the release. “We are working closely with Air Mobility Command and all operational users and anticipate all potentially affected aircraft will be inspected.”

The release notes that the issue has not caused any mishaps.

The backbone of the refueling fleet, the KC-135 first entered service during the Eisenhower administration and is slowly being replaced by deliveries of the KC-46 and the future KC-Y platform. The Air Force has 396 of the tankers in its inventory, according to a service fact sheet, along with 17 RC-135s and 2 WC-135s.

The tail pin issue, which was first reported by Defense News, requires a relatively simple 30-minute inspection, according to the Air Force release. Aircraft are then cleared for flight if the tail pin is compliant.

If the inspection turns up an issue with the tail pin, aircraft are authorized for a one-time flight to a repair location, a process the Air Force says will take about a day. The service anticipates that most tail pin replacement work will likely take place at the Oklahoma City Air Logistics Complex.

The Air Force said that as of Feb. 12, 90 aircraft were inspected for the issue and 24 had non-conforming tail pins. Aircraft that have already been inspected and whose tail pins were found to be compliant have returned to flight.