The German Air Force has grounded its entire fleet of 55 Eurofighter combat jets for an indefinite period due to technical problems with the plane’s ejection seats.

The air force will use the older F-4 Phantom fighter jets, which are being replaced by the Eurofighter to perform air policing of skies over southern Germany.

The decision has been taken following the crash of a two-seat Eurofighter at the end of August at Moron Air Base, near Seville in Spain, according to Businessweek.

During the incident, the Spanish pilot escaped successfully using the ejection seat, while the Saudi co-pilot died because the parachute disconnected from the seat.