14 CFR § 23.2115

The applicant must determine airplane takeoff performance accounting for—

Stall speed safety margins;

Minimum control speeds; and

Climb gradients.

For single engine airplanes and levels 1, 2, and 3 low-speed multiengine airplanes, takeoff performance includes the determination of ground roll and initial climb distance to 50 feet (15 meters) above the takeoff surface.

For levels 1, 2, and 3 high-speed multiengine airplanes, and level 4 multiengine airplanes, takeoff performance includes a determination of the following distances after a sudden critical loss of thrust—

An aborted takeoff at critical speed;

Ground roll and initial climb to 35 feet (11 meters) above the takeoff surface; and

Net takeoff flight path.