- No design constraints specified, your paper airplane could be any style that suited you.
- paper airplanes must be constructed from a single sheet of paper (no size limit specified)
- weighting was allowed (no weight limit specified)
The day of the contest I walked out into the middle of the school gym with a single large sheet of construction paper and a dollar and fifty cents in quarters in my pocket. I placed the quarters in the middle of the paper then carefully crumpled it into a ball in such a way to ensure the coins were trapped. I then threw it the full length of the gym and out the gym doors, tripling the closest best distance. I was immediately pulled aside by several teachers and informed I was disqualified, with no reasons for the disqualification given. Moral: none that I can discern.
I understand why it felt unjust to you at the time. But even if you go 100% rules lawyer, the disqualification was correct.