what is the ideal thrust is to weight ratio for powered flight,should it be more than 1or less than 1?

Answer 1

There is no IDEAL thrust to weight ratio. The ratio you want depends very greatly on the application to which it is applied.

For example, if your vehicle has no wings, the only thing holding it up in the air is the thrust, so the ratio will have to be AT LEAST 1, or it's just going nowhere. And you probably want it much higher than that, but not too high or the vehicle and its cargo may not survive.

On the other hand, if you have a dirigible, it require no energy to remain aloft because of its bouyancy, and a high thrust to weight ratio is more likely to damage the fragile construction of the craft rather than get you going really fast.

The ratio is a good means of measuring comparative output, but that hardly suggests it's the only or even the biggest consideration. Hope that helps!