June 24 (UPI) -- A tornado at a U.S. Air Force base in Nebraska damaged 10 aircrafts including two E-4B "doomsday" planes.
The two E-4Bs, which serve as the military's National Airborne Operations Center during national emergencies, were knocked out of service when a tornado struck Offutt Air Force Base on June 16.
In the event ground bases are destroyed, the "doomsday" plane acts as the command and control hub for the president, secretary of defense and joint chiefs.
The U.S. military has a total of four E-4B planes in the fleet, but officials said it would still be able to carry out a mission with half the fleet damaged.
"There is no impact to the E-4B's primary mission, so it remains capable of completing its National Airborne Operations Center," Air Force spokesman Col. Patrick Ryder told CNN.
Eight RC-135 reconnaissance aircrafts were also damaged by the tornado and six have since been returned to mission-capable status.