Thrust/Lift um, Perpetual energy?

[FakePilot]

Hi All!

I searched for "thrust lift energy" and didn't find a posting, so I ask:

Ok, this is killing me. For years and years I have always wondered, How can an airplane generating 100,000 lbs of thrust lift 700,000 lbs of weight?????? Approx 777, I think?

I understand if you have a rocket which weighs 5 lbs and produces 5 lbs of thrust it will hover. Ok fine.

The best way to illustrate the problem is as follows:

You have a car with a propeller on it, which is the sole method of propulsion. The wheels are just free spinning.

You have a wing on top connected to a generator. The wing lifts up, falls down, lifts up.

The generator drives the motor for the propeller.

Now, wouldn't it therefore be possible at the right speed to just keep cruising forever?

I understand that there's loss of efficienty because of the motor, generator and mechanical wing mechinism, but hey at like 5:1 lift/thrust ratio, that should cover it?

Thanks!