My father, was mustered out of the Air Force, and trains to home were scarce.
In his free 2 weeks before leaving California, he chose to visit Salinas AFB.
After visiting friends there he accidentally wandered into a restricted area.
In a large hangar, labelled Top Secret, he observed and examined 3 flying disks.
All had USAF markings, and tripod landing gear.
No obvious method of propulsion could be found.
He was arrested, interrogated and forced to sign a secrecy agreement.
Some of this was done at pistol point.
He deeply resented being treated that way by his government.
He told me of this incident before he died in 1990.
There aren't aliens flying those UFOs, they are ours.