OK, for all you who fly in the USA with AMA.

AMA rules prohibit any powered projectile launch from any airplane. Powered includes CO2 and spring powered BB guns, and unguided rockets.

All pyrotechnics are prohibited, except for powering the airplane itself. This allows the use of model rocket engines for JATO, or to power an air dropped r/c model.

Recap: Under AMA you can not put an unguided rocket, or any form of gun on your plane and have AMA coverage.

Beyond that, face the lawyers on your own.

Bill.