[Capt. Tom]

I was pointing to your statement that runway length is influenced by passenger comfort. It is not.

If a plane load of passengers has to land on a short runway the breaking and engine noise is uncomfortable for them.
Ask any Freeper who flew into St Thomas on American Airlines jets before they lengthened the runway. If you had a book on the seat next to you it would come sliding off and hit the seat ahead ,you would get jammed forward against your seatbelt. . St Thomas definaely needed a longer runway.- Tom

On April 27, 1976, American Airlines Flight 625 ran off the end of the runway, killing 37 of the 88 on board the aircraft. Following the crash, American Airlines suspended jet service, to the airport, using propliners until the runway was rebuilt to its present length.

[old curmudgeon]

On April 27, 1976, American Airlines Flight 625 ran off the end of the runway, killing 37 of the 88 on board the aircraft. Following the crash, American Airlines suspended jet service, to the airport, using propliners until the runway was rebuilt to its present length. Yes, I would say that those passengers were not comfortable. But this not not what determines runway length. Below is just a small part of what determines runway length. Temperature, altitude and wind may make a runway unusable on one day and usable the next. Note that the rule says no pilot will take off unless the aircraft can ....ect. It does not say what "can"is. That is determined by the aircraft manual. An aircraft can use one runway today that is not the longest on that airport because he is light and can meet the accelerate/stop distances. On the next day, the load on board, the temperature and the wind may require him to use the longer runway. Passenger comfort has nothing to do with it. §121.189 Airplanes: Turbine engine powered: Takeoff limitations. (a) No person operating a turbine engine powered airplane may take off that airplane at a weight greater than that listed in the Airplane Flight Manual for the elevation of the airport and for the ambient temperature existing at takeoff. (b) No person operating a turbine engine powered airplane certificated after August 26, 1957, but before August 30, 1959 (SR422, 422A), may take off that airplane at a weight greater than that listed in the Airplane Flight Manual for the minimum distances required for takeoff. In the case of an airplane certificated after September 30, 1958 (SR422A, 422B), the takeoff distance may include a clearway distance but the clearway distance included may not be greater than 1⁄2 of the takeoff run. (c) No person operating a turbine engine powered airplane certificated after August 29, 1959 (SR422B), may take off that airplane at a weight greater than that listed in the Airplane Flight Manual at which compliance with the following may be shown: (1) The accelerate-stop distance must not exceed the length of the runway plus the length of any stopway. (2) The takeoff distance must not exceed the length of the runway plus the length of any clearway except that the length of any clearway included must not be greater than one-half the length of the runway. (3) The takeoff run must not be greater than the length of the runway. (d) No person operating a turbine engine powered 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. (e) In determining maximum weights, minimum distances, and flight paths under paragraphs (a) through (d) of this section, correction must be made for the runway to be used, the elevation of the airport, the effective runway gradient, the ambient temperature and wind component at the time of takeoff, and, if operating limitations exist for the minimum distances required for takeoff from wet runways, the runway surface condition (dry or wet). Wet runway distances associated with grooved or porous friction course runways, if provided in the Airplane Flight Manual, may be used only for runways that are grooved or treated with a porous friction course (PFC) overlay, and that the operator determines are designed, constructed, and maintained in a manner acceptable to the Administrator. (f) For the purposes of this section, it is assumed that the airplane is not banked before reaching a height of 50 feet, as shown by the takeoff path or net takeoff flight path data (as appropriate) in the Airplane Flight Manual, and thereafter that the maximum bank is not more than 15 degrees. (g) For the purposes of this section the terms, takeoff distance, takeoff run, net takeoff flight path and takeoff path have the same meanings as set forth in the rules under which the airplane was certificated. [Doc. No. 6258, 29 FR 19198, Dec. 31, 1964, as amended by Amdt. 121-268, 63 FR 8321, Feb. 18, 1998]