VMC for takeoff must not exceed 1.2 VS1, where VS1 is determined at the maximum takeo
why the bit in the title?
thanks for the help
cheers
FAR PART 23.149
FAR 23 (the certification requirements for typical general-aviation13 airplanes) gives a very specific definition of VMC, namely:
FAR 23.149 Minimum control speed.
(a) VMC is the calibrated airspeed at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the airplane with that engine still inoperative, and thereafter maintain
straight flight at the same speed with an angle of bank of not more than 5 degrees. The method used to simulate critical engine failure must represent the most critical mode of powerplant failure expected in service with respect to controllability.
(b) VMC for takeoff must not exceed 1.2 VS1, where VS1 is determined at the maximum takeoff weight. VMC must be determined with the most unfavorable weight and center of gravity position and with the airplane airborne and the ground effect negligible, for the takeoff configuration(s) with--
(1) Maximum available takeoff power initially on each engine;
(2) The airplane trimmed for takeoff;
(3) Flaps in the takeoff position(s);
(4) Landing gear retracted; and
(5) All propeller controls in the recommended takeoff position throughout.
Note that none of these definitions require that the airplane exhibit a positive rate of climb at VMC. Also note that during a VMC demonstration, the pilot is not required to optimize the climb rate or to maintain zero slip -- although zero slip may be an advantage if it can be achieved.