DOVER — The U.S. Air Force Air Mobility Command has ordered Dover Air Force Base’s fleet of C-5M Galaxy cargo planes grounded.

Twice in 60 days, there have been nose landing gear malfunctions.

The order came Monday after a C-5’s emergency landing at Naval Station Rota in Spain, officials said. The standdown was ordered for all 18 aircraft from Dover until inspections deemed them safe.

According to officials, the latest incident was similar to the first — a nose landing gear did not properly engage. The C-5 landed safely at the base and then was grounded until further notice

“Aircrew safety is always my top priority and is taken very seriously,” said Gen. Carlton D. Everhart II, Air Mobility Command commander. “We are taking the appropriate measures to properly diagnose the issue and implement a solution.”

According to the AMC, inspections will occur to ensure the proper extension and retraction of the C-5 nose landing gear.

No details on the method of inspections or the estimated time needed was immediately available Tuesday.

During the C-5 stand-down at Dover, AMC said it will work to ensure worldwide mission requirements are minimally impacted. Eighteen C-5 aircraft are assigned to Dover AFB. There are 56 C-5 aircraft in the Air Force fleet. The stand-down only impacts Dover AFB.

The 18 DAFB aircaft include primary and backup aircraft inventory assigned to Dover. Twelve primary aircraft are assigned to Dover.

A spokeswoman said Tuesday that inspection results from the first incident hahd not been released.

On May 23, a C-5 Galaxy’s nose landing gear did not fully descend upon arrival at Naval Station Rota, and the aircraft was successfully piloted to the ground by the crew.

The aircraft remained stuck on the runway after crew and passengers deplane. The AMC said the airfield returned to a mission capable status in 12 hours on a day when more than double the average air traffic was transiting Rota and several critically important missions hung in the balance, according to military officials.