The U.S. Air Force is struggling to fill a shortage of 700 fighter pilots by the end of the year, even as the U.S. battles in three air wars against ISIS in Iraq, Syria and Libya.

“It is a crisis,” said the U.S. Air Force’s new top officer, Gen. David Goldfein, aside Air Force Secretary Deborah Lee James at the annual “State of the Air Force” briefing at the Pentagon Wednesday.

“Air superiority is not an American birthright,” Goldfein said. “It’s actually something you have to fight for and maintain.”

Fox News first reported the Air Force shortage of 700 pilots after visiting two Air Force bases in May.

Airmen told Fox News, in addition to the pilot shortage, they are 4,000 mechanics short as well.

Shorthanded crews are now forced to scrounge for spare parts in museums and the “boneyard,” a graveyard of planes in the Arizona desert to fix their planes because the parts are not made anymore.

Air Force Secretary Deborah Lee James said Wednesday that she is planning to pay drone pilots a $35,000 a year retention bonus to encourage them to stay in the service.

Read more at Fox News