[Cammysmom]

This was the flight number of one of the planes that hit a tower.

[Hugh Akston]

That is an urban legend. There are no flights that begin their identifier with the letter "Q".

If you go to The Urban Legends Reference Pages you can find a link at the top to a summary of all the WTC/Pentagon attack myths that are cropping up (including a few that are true.

[MooCollins]

This was NOT the flight number of any flight on that date.
This was a hoax and I am tired of seeing it.