The Swiss Air Force is retiring nearly a third of its F-5E/F Tiger jets and repairing six others after discovering of structural cracks.
The Swiss Department of Defense, Civil Protection & Sports said a major crack on an F-5 Tiger's supporting structure was found in 2014 on an aircraft undergoing a major overhaul. A similar crack was found on a second aircraft this January, and the Air Force then ordered an inspection of its entire F-5 fleet.
Repair work on six of the F-5s will cost about $1 million.
The Swiss government said repairs on the six aircraft will be completed in the first quarter of next year. Additional details, however, were not disclosed.
The Northrop F-5 entered into service with the U.S. military in 1962. The Swiss Air Force acquired 110 single seat and double-seat variants between 1978 and 1984.