what determines the minimum airspeed of an aeroplane in straight and level flight?

Answer 1

well, it's the area of the wing of the lifting surface, the weight of the plane, along with the pitch angle witch can be adjusted to generate more down force, but a high pitch angle would cause the plane to stall and maybe crash, also the altitude; planes can fly slower at lower altitude because the air is more dense there which means that less speed can generate enough life for it to fly..

Answer 2

The amount of lift, which is determined by the weight of the airframe and the design of the wings. There are ultra-lights that can safely fly, straight and level at about 10-15 mph. They have been known to "sit still" in the air, if encountering a slight headwind.

Answer 3

An airplane flies due to followings:
1. Thrust
2. Lift
3. Drag
4. Gravitational Pull

Thrust is Opposite to Drag and Lift is opposite to Gravitational Pull. If one of these factors is out of balance, the plane will not be able to continue.

So, as regards to your question, all these four factors will decide a straight and level flight.

Answer 4

Lift

Answer 5

SPEEDOMETER