He must’ve had his head in the clouds.

A flighty JetBlue pilot allegedly forgot he had a firearm packed in his luggage as he tried to board a plane out of LaGuardia Airport, The Post has learned.

Captain Robert Paulson, 47, apparently didn’t remember the 40-caliber H&K pistol stashed in his bag as he presented it for pre-flight screening at a security checkpoint at 10 a.m. on Sept. 8, law enforcement sources said.

An eagle-eyed Transportation Security Administration officer spied the weapon as the bag made its way through the x-ray machine in Terminal A, the sources added.

The TSA agent also found a magazine with 10 live rounds loose inside Paulson’s backpack, the sources continued.

Paulson was deadheading – an aviation term for hitching a free ride – to Chicago on Delta Airlines flight 5939, the sources said.

He allegedly admitted the gun was his and that he didn’t have a license to carry in New York State.

Paulson, who lives in Ankeny, Iowa, was arrested and charged with weapons possession, said a spokesman for Queens DA Richard Brown. He was released without bail after his arraignment and is due back in court on Sept. 29.