[secretagent]

Thanks for the explanation. I'd never heard that before, but your version sounds plausible.

[jlogajan]

I should say that I was private pilot rated at one point in my life (single engine, land, non-instrument, i.e. your typical weekend warrior type.)

Anyhow, you had to know where your COG was before you took off. There were a series of calculations for passenger weight, luggage, fuel, etc. And where they were distributed. If you had heavy luggage back in the luggage compartment you might not be able to take off, not because you were overweight, but because your COG was too far back.

You would simply be outside the safe operating range of the craft -- it couldn't get it's COL far enough back -- you could lose control of the craft.

There have been accidents where the airplane engine has come off (broken prop tears engine loose.) Pity the poor pilot. The aircraft is fine otherwise, but the COG is now so far off from the COL that the aircraft is uncontrollable. The aircraft will probably porpoise a few times before breaking up due to overspeeds on uncontrolled decent portions.