takeoff distance required

i. The horizontal distance required to accelerate from a standing start with all engines operating to achieve a safety speed at a height of 50 ft above the takeoff surface, multiplied by 1.15 for airplanes with a maximum takeoff weight of 4500 lb (2000 kg); 1.25 with a maximum takeoff of 6750 lb (3000 kg) or greater; or a factor derived by linear interpolation between 1.15 and 1.25, according to the maximum takeoff weight of the airplane, for airplanes with the maximum takeoff weight between 4500 and 6750 lb (2000 and 3000 kg). For airplanes operated on land, takeoff distances are determined for a level, short, dry surface. For airplanes operated on water, takeoff distances must account for the maximum crosswind component and the most adverse water conditions. Where the TODR is specified in the manufacturer’s manual, it should be followed provided the above criteria are met.

ii. As it pertains to helicopters, TODRH is the distance from the point of the commencement of takeoff to the point at which the helicopter achieves the minimum speed at which climb is achieved with the critical power unit inoperative and the remaining power units operating within approved operating limits. V_TOSS is the minimum speed for a rotorcraft at which climb is achieved with the critical power unit inoperative and the remaining power units operating within approved operating limits. The speed may be measured by instrument indications or achieved by a procedure specified in the flight manual. See takeoff decision point.