Metro

Armed nut nabbed at airport

A crazed, knife-wielding Lower East Side man was in custody last night after he was caught running on the tarmac at Newark Airport.

Xiang Xun Shao, 39, of 288 Broome St., vaulted over a mechanical barrier and “gained access to the aeronautical area of operations,” at around 6:30 p.m., according to law-enforcement sources.

Shao had been seen lingering next to a guardhouse adjacent to the Continental Airlines taxiway ramp at the airport’s Terminal C.

He suddenly jumped the barrier and sprinted across the tarmac with a guard in hot pursuit, sources said.

Shao tripped and was tackled by Port Authority police just feet from several passenger jets, they said.

He was taken to Beth Israel Hospital in Newark for a psychiatric evaluation and is charged with criminal trespassing and criminal possession of a weapon, authorities said.

The runway rundown comes less than a week after a dripping wet, naked homeless man scaled a fence near a fuel storage facility at JFK airport.