A mother and her young son were flying Air Lingus. The son, who had been looking out the plane's window, turned to his mother and said, "Mom, if big dogs have baby dogs and big cats have baby cats, why don't big planes have baby planes?"
Stumped, the mother suggested to her son that he ask the stewardess. The boy promptly got out of his seat and wandered back to the service area.
"Excuse me," the boy said to the stewardess. "If big dogs have baby dogs and big cats have baby cats, why don't big planes have baby planes?"
"Did your mother tell you to ask me that?"
"Yes," he said, nodding his head.
The stewardess whispered in the boy's ear, "Tell your mother it's because Air Lingus always pulls out on time."