In flight mechanics, “thrust minimum” refers to a specific flight condition where an aircraft is operating at the point of minimum thrust required to maintain level flight at a given airspeed. At this condition, the aircraft is typically flying at its most efficient state in terms of engine power and fuel consumption for a given speed and altitude.
 Tmin=W(Cd/Cl) min
Tmin = Minimum thrust required for level flight w = Weight of the aircraft Cd = Drag coefficient Cl = Lift coefficient