envelope
131center-of-gravity envelope — An envelope drawn on a graph included in aircraft certificates, data sheets, and flight manuals, showing the way the center of gravity may vary with the gross weight of an aircraft. Any combination of weight and the center of gravity that falls… …
132on the back of an envelope — (informal) Said of a calculation that is performed quickly and without scrupulous regard to accuracy • • • Main Entry: ↑envelop * * * on the back of an envelope phrase quickly and without thinking about all the details The proposal was no doubt… …
