Off Course by Mack Reynolds, Science Fiction, Fantasy

First on the scene were Larry Dermott and Tim Casey of the State Highway Patrol. They assumed they were witnessing the crash of a new type of Air Force plane and slipped and skidded desperately across the field to within thirty feet of the strange craft, only to discover that the landing had been made without accident.
Patrolman Dermott shook his head. "They're gettin' queerer looking every year. Get a load of it -- no wheels, no propeller, no cockpit."
They left the car and made their way toward the strange egg-shaped vessel.
Tim Casey loosened his .38 in its holster and said, "Sure, and I'm beginning to wonder if it's one of ours. No insignia and --"
A circular door slid open at that point and Dameri Tass stepped out, yawning. He spotted them, smiled and said, "Glork."
They gaped at him.
"Glork is right," Dermott swallowed.