"The Airplane" joke

A pilot was flying a 747 full of passengers as a voice cracked
over the radio.
It said, "This is Ground Control. Please divert your course 5
degrees east. Over."
The pilot was slightly confused and responded, "10-4, but why
should I divert my course?"
The voice answered, "Your plane and another 747 are about to
pass over a major city and we don't want any excess noise."
The pilot laughed and said, "I'm 31, 000 feet up. What kind of
noise could I cause?"
Ground Control answered, "Have you ever heard the sound that
colliding 747's make?"