Originally Posted by JammedStab
there may be no regulation covering this subject
This is the regulation:
Sec. 25.111
Takeoff path.
(a) The takeoff path extends from a standing start to a point in the takeoff at which the airplane is 1,500 feet above the takeoff surface, or at which the transition from the takeoff to the en route configuration is completed and VFTO is reached, whichever point is higher. In addition--
Sec. 121.189
Airplanes: Turbine engine powered: Takeoff limitations.
(d) No person operating a turbine engine powered transport category airplane may take off that airplane at a weight greater than that listed in the Airplane Flight Manual--
(1) In the case of an airplane certificated after August 26, 1957, but before October 1, 1958 (SR422), that allows a takeoff path that clears all obstacles either by at least (35+0.01D) feet vertically (D is the distance along the intended flight path from the end of the runway in feet), or by at least 200 feet horizontally within the airport boundaries and by at least 300 feet horizontally after passing the boundaries; or
(2) In the case of an airplane certificated after September 30, 1958 (SR 422A, 422B), that allows a net takeoff flight path that clears all obstacles either by a height of at least 35 feet vertically, or by at least 200 feet horizontally within the airport boundaries and by at least 300 feet horizontally after passing the boundaries.
Then there is Advisory Circular 120-91:
1. PURPOSE.
This advisory circular (AC) describes acceptable methods and guidelines for developing takeoff and initial climb-out airport obstacle analyses and in-flight procedures to comply with the intent of the regulatory requirements of Title 14 of the Code of Federal Regulations (...) relating to turbine engine
powered airplanes operated under parts 121 and 135. The methods and guide lines presented in this AC are neither mandatory nor the only acceptable methods for ensuring compliance with the regulatory sections. Operators may use other methods if those methods are shown to provide the necessary level of safety and are acceptable to the Federal Aviation Administration (FAA). (...).
9. TERMINATION OF TAKEOFF SEGMENT.
a. For the purpose of the takeoff obstacle clearance analysis, the end of the takeoff flightpath is considered to occur when:
(1) The airplane has reached the minimum crossing altitude (MCA) at a fix or the minimum en route altitude (MEA) for a route to the intended destination;
(2) The airplane is able to comply with en route obstacle clearance requirements (§§ 121.191, 121.193, 135.381, and 135.383); or
(3) The airplane has reached the minimum vectoring altitude, or a fix and altitude from which an approach may be initiated, if the operator’s emergency procedure calls for an immediate return to the departure airport or a diversion to the departure alternate in the event of an engine failure during takeoff.
b. When determining the limiting takeoff weight, the obstacle analysis should be carried out to the end of the takeoff segment as defined in paragraph 9a above. Operators should note that the end of the takeoff segment is determined by the airplane’s gross flightpath, but the obstacle analyses must use the net flightpath data.
c. In the event that the airplane cannot return to and land at the departure airport, the takeoff flightpath should join a suitable en route path to the planned destination or to another suitable airport. It may be necessary to address extended times and alternate fuel requirements when climbing in a holding pattern with reduced climb gradients associated with one-engine-inoperative turns.