A group of aeronautical engineering professors were invited to fly for free on a new aircraft that was just being introduced.

As the door was closing and the plane was about to take off, a voice over the intercom said, “Thank you for your confidence in taking the inaugural flight on this new aircraft. It was designed and built by all of your students over this past year.

All the professors began to unbuckle their seatbelts and make their way to the exit door of the plane, with the exception of one, who remained calmly seated with a smile on his face.

One of the professors who was standing in line to exit the plane asked him why he wasn’t getting off of the plane, knowing that the plane was built by some of his recent students.

The Professor replied, “Because they are our students.”

Another professor who was standing close by asked, “So you are sure that you taught your students well enough to build this?

The sitting professor smiled and said, “No, I’m not sure, but I AM sure that it won’t fly.”