Vc
From Free net encyclopedia
The VC of an aircraft is the V speed which refers to the velocity of cruising. VC is within the green arc on many airspeed indicators. This speed specific to the aircraft model.
VC is also called the design cruising speed or the optimum cruise speed – the latter being the speed giving the most velocity (i.e greatest distance/time) from a litre of fuel, usually utilising 75% power at Maximum Take-Off Weight (MTOW) and about 1.3 times the maximum L/D speed – Vbr above. The speed and power required decrease as the aircraft weight decreases from MTOW.
For normal category aircraft FAR part 23 specifies a minimum design cruising speed = 33 √ W/S. For utility category the minimum design cruising speed (in knots) = 36 √ W/S. For this calculation the wing loading W/S is expressed in pounds per square foot. Many ultralight aeroplanes are unable to comply with the FAR part 23 requirement for a minimum design cruising speed.