Fear of flying should take a vacation — despite yesterday’s discovery that three more Southwest Airlines jets have cracks in their fuselages, an aviation expert told The Post.

“You have a very rare incident being taken extremely seriously,” said Andy Golub of Ascend, a New York-based air-transport consultant.

Still, the Federal Aviation Administration yesterday said they will order emergency checks of some older 737s for the kind of fatigue cracks that prompted Southwest Airlines to ground dozens of planes and cancel hundreds of flights.

The small subsurface cracks revealed yesterday were similar to those suspected of causing a gaping hole Friday in a Southwest 737’s ceiling — prompting a successful emergency landing with no injuries.