--- kind: "range" citation: "14 C.F.R. §§ 121.175–121.197" title: "14" from: "121.175" to: "121.197" count: 12 url: "https://uscodex.org/cfr/14/121.175..121.197" --- # §121.175. Airplanes: Reciprocating engine-powered: Weight limitations. - (a) No person may take off a reciprocating engine powered airplane from an airport located at an elevation outside of the range for which maximum takeoff weights have been determined for that airplane. - (b) No person may take off a reciprocating engine powered airplane for an airport of intended destination that is located at an elevation outside of the range for which maximum landing weights have been determined for that airplane. - (c) No person may specify, or have specified, an alternate airport that is located at an elevation outside of the range for which maximum landing weights have been determined for the reciprocating engine powered airplane concerned. - (d) No person may take off a reciprocating engine powered airplane at a weight more than the maximum authorized takeoff weight for the elevation of the airport. - (e) No person may take off a reciprocating engine powered airplane if its weight on arrival at the airport of destination will be more than the maximum authorized landing weight for the elevation of that airport, allowing for normal consumption of fuel and oil en route. - (f) This section does not apply to large nontransport category airplanes operated under [§ 121.173(c)](/cfr/14/121.173.md?p=c). # §121.177. Airplanes: Reciprocating engine-powered: Takeoff limitations. - (a) No person operating a reciprocating engine powered airplane may takeoff that airplane unless it is possible— - (1) To stop the airplane safely on the runway, as shown by the accelerate stop distance data, at any time during takeoff until reaching critical-engine failure speed; - (2) If the critical engine fails at any time after the airplane reaches critical-engine failure speed V1, to continue the takeoff and reach a height of 50 feet, as indicated by the takeoff path data, before passing over the end of the runway; and - (3) To clear all obstacles either by at least 50 feet vertically (as shown by the takeoff path data) or 200 feet horizontally within the airport boundaries and 300 feet horizontally beyond the boundaries, without banking before reaching a height of 50 feet (as shown by the takeoff path data) and thereafter without banking more than 15 degrees. - (b) In applying this section, corrections must be made for the effective runway gradient. To allow for wind effect, takeoff data based on still air may be corrected by taking into account not more than 50 percent of any reported headwind component and not less than 150 percent of any reported tailwind component. - (c) This section does not apply to large nontransport category airplanes operated under [§ 121.173(c)](/cfr/14/121.173.md?p=c). # §121.179. Airplanes: Reciprocating engine-powered: En route limitations: All engines operating. - (a) No person operating a reciprocating engine powered airplane may take off that airplane at a weight, allowing for normal consumption of fuel and oil, that does not allow a rate of climb (in feet per minute), with all engines operating, of at least 6.90 VSo (that is, the number of feet per minute is obtained by multiplying the number of knots by 6.90) at an altitude of at least 1,000 feet above the highest ground or obstruction within ten miles of each side of the intended track. - (b) **This section does not apply to airplanes certificated under part 4a of the Civil Air Regulations.** - (c) This section does not apply to large nontransport category airplanes operated under [§ 121.173(c)](/cfr/14/121.173.md?p=c). # §121.181. Airplanes: Reciprocating engine-powered: En route limitations: One engine inoperative. - (a) Except as provided in [paragraph (b)](#b) of this section, no person operating a reciprocating engine powered airplane may take off that airplane at a weight, allowing for normal consumption of fuel and oil, that does not allow a rate of climb (in feet per minute), with one engine inoperative, of at least - (b) In place of the requirements of [paragraph (a)](#a) of this section, a person may, under an approved procedure, operate a reciprocating engine powered airplane, at an all-engines-operating altitude that allows the airplane to continue, after an engine failure, to an alternate airport where a landing can be made in accordance with [§ 121.187](/cfr/14/121.187.md), allowing for normal consumption of fuel and oil. After the assumed failure, the flight path must clear the ground and any obstruction within five miles on each side of the intended track by at least 2,000 feet. - (c) If an approved procedure under [paragraph (b)](#b) of this section is used, the certificate holder shall comply with the following: - (1) The rate of climb (as prescribed in the Airplane Flight Manual for the appropriate weight and altitude) used in calculating the airplane's flight path shall be diminished by an amount, in feet per minute, equal to - (2) The all-engines-operating altitude shall be sufficient so that in the event the critical engine becomes inoperative at any point along the route, the flight will be able to proceed to a predetermined alternate airport by use of this procedure. In determining the takeoff weight, the airplane is assumed to pass over the critical obstruction following engine failure at a point no closer to the critical obstruction than the nearest approved radio navigational fix, unless the Administrator approves a procedure established on a different basis upon finding that adequate operational safeguards exist. - (3) The airplane must meet the provisions of [paragraph (a)](#a) of this section at 1,000 feet above the airport used as an alternate in this procedure. - (4) The procedure must include an approved method of accounting for winds and temperatures that would otherwise adversely affect the flight path. - (5) In complying with this procedure fuel jettisoning is allowed if the certificate holder shows that it has an adequate training program, that proper instructions are given to the flight crew, and all other precautions are taken to insure a safe procedure. - (6) The certificate holder shall specify in the dispatch or flight release an alternate airport that meets the requirements of [§ 121.625](/cfr/14/121.625.md). - (d) This section does not apply to large nontransport category airplanes operated under [§ 121.173(c)](/cfr/14/121.173.md?p=c). # §121.183. Part 25 airplanes with four or more engines: Reciprocating engine powered: En route limitations: Two engines inoperative. - (a) No person may operate an airplane certificated under [part 25](/cfr/14/part25.md) and having four or more engines unless— - (1) There is no place along the intended track that is more than 90 minutes (with all engines operating at cruising power) from an airport that meets the requirements of [§ 121.187](/cfr/14/121.187.md); or - (2) It is operated at a weight allowing the airplane, with the two critical engines inoperative, to climb at 0.013 Vso2 feet per minute (that is, the number of feet per minute is obtained by multiplying the number of knots squared by 0.013) at an altitude of 1,000 feet above the highest ground or obstruction within 10 miles on each side of the intended track, or at an altitude of 5,000 feet, whichever is higher. - (b) **For the purposes of paragraph (a)(2) of this section, it is assumed that—** - (1) **The two engines fail at the point that is most critical with respect to the takeoff weight—** - (2) Consumption of fuel and oil is normal with all engines operating up to the point where the two engines fail and with two engines operating beyond that point; - (3) Where the engines are assumed to fail at an altitude above the prescribed minimum altitude, compliance with the prescribed rate of climb at the prescribed minimum altitude need not be shown during the descent from the cruising altitude to the prescribed minimum altitude, if those requirements can be met once the prescribed minimum altitude is reached, and assuming descent to be along a net flight path and the rate of descent to be 0.013 Vso2 greater than the rate in the approved performance data; and - (4) If fuel jettisoning is provided, the airplane's weight at the point where the two engines fail is considered to be not less than that which would include enough fuel to proceed to an airport meeting the requirements of [§ 121.187](/cfr/14/121.187.md) and to arrive at an altitude of at least 1,000 feet directly over that airport. # §121.185. Airplanes: Reciprocating engine-powered: Landing limitations: Destination airport. - (a) Except as provided in [paragraph (b)](#b) of this section no person operating a reciprocating engine powered airplane may take off that airplane, unless its weight on arrival, allowing for normal consumption of fuel and oil in flight, would allow a full stop landing at the intended destination within 60 percent of the effective length of each runway described below from a point 50 feet directly above the intersection of the obstruction clearance plane and the runway. For the purposes of determining the allowable landing weight at the destination airport the following is assumed: - (1) **The airplane is landed on the most favorable runway and in the most favorable direction in still air.** - (2) The airplane is landed on the most suitable runway considering the probable wind velocity and direction (forecast for the expected time of arrival), the ground handling characteristics of the type of airplane, and other conditions such as landing aids and terrain, and allowing for the effect of the landing path and roll of not more than 50 percent of the headwind component or not less than 150 percent of the tailwind component. - (b) An airplane that would be prohibited from being taken off because it could not meet the requirements of [paragraph (a)(2)](#a-2) of this section may be taken off if an alternate airport is specified that meets all of the requirements of this section except that the airplane can accomplish a full stop landing within 70 percent of the effective length of the runway. - (c) This section does not apply to large nontransport category airplanes operated under [§ 121.173(c)](/cfr/14/121.173.md?p=c). # §121.187. Airplanes: Reciprocating engine-powered: Landing limitations: Alternate airport. - (a) No person may list an airport as an alternate airport in a dispatch or flight release unless the airplane (at the weight anticipated at the time of arrival at the airport), based on the assumptions in [§ 121.185](/cfr/14/121.185.md), can be brought to a full stop landing, within 70 percent of the effective length of the runway. - (b) This section does not apply to large nontransport category airplanes operated under [§ 121.173(c)](/cfr/14/121.173.md?p=c). # §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)](#a..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. # §121.191. Airplanes: Turbine engine powered: En route limitations: One engine inoperative. - (a) No person operating a turbine engine powered airplane may take off that airplane at a weight, allowing for normal consumption of fuel and oil, that is greater than that which (under the approved, one engine inoperative, en route net flight path data in the Airplane Flight Manual for that airplane) will allow compliance with [paragraph (a)](#a) (1) or (2) of this section, based on the ambient temperatures expected en route: - (1) There is a positive slope at an altitude of at least 1,000 feet above all terrain and obstructions within five statute miles on each side of the intended track, and, in addition, if that airplane was certificated after August 29, 1959 (SR 422B) there is a positive slope at 1,500 feet above the airport where the airplane is assumed to land after an engine fails. - (2) The net flight path allows the airplane to continue flight from the cruising altitude to an airport where a landing can be made under [§ 121.197](/cfr/14/121.197.md), clearing all terrain and obstructions within five statute miles of the intended track by at least 2,000 feet vertically and with a positive slope at 1,000 feet above the airport where the airplane lands after an engine fails, or, if that airplane was certificated after September 30, 1958 (SR 422A, 422B), with a positive slope at 1,500 feet above the airport where the airplane lands after an engine fails. - (b) **For the purposes of paragraph (a)(2) of this section, it is assumed that—** - (1) The engine fails at the most critical point en route; - (2) The airplane passes over the critical obstruction, after engine failure at a point that is no closer to the obstruction than the nearest approved radio navigation fix, unless the Administrator authorizes a different procedure based on adequate operational safeguards; - (3) **An approved method is used to allow for adverse winds—** - (4) Fuel jettisoning will be allowed if the certificate holder shows that the crew is properly instructed, that the training program is adequate, and that all other precautions are taken to insure a safe procedure; - (5) The alternate airport is specified in the dispatch or flight release and meets the prescribed weather minimums; and - (6) The consumption of fuel and oil after engine failure is the same as the consumption that is allowed for in the approved net flight path data in the Airplane Flight Manual. # §121.193. Airplanes: Turbine engine powered: En route limitations: Two engines inoperative. - (a) **Airplanes certificated after August 26, 1957, but before October 1, 1958—** (SR 422). No person may operate a turbine engine powered airplane along an intended route unless he complies with either of the following: - (1) There is no place along the intended track that is more than 90 minutes (with all engines operating at cruising power) from an airport that meets the requirements of [§ 121.197](/cfr/14/121.197.md). - (2) Its weight, according to the two-engine-inoperative, en route, net flight path data in the Airplane Flight Manual, allows the airplane to fly from the point where the two engines are assumed to fail simultaneously to an airport that meets the requirements of [§ 121.197](/cfr/14/121.197.md), with a net flight path (considering the ambient temperature anticipated along the track) having a positive slope at an altitude of at least 1,000 feet above all terrain and obstructions within five miles on each side of the intended track, or at an altitude of 5,000 feet, whichever is higher. - (b) **Aircraft certificated after September 30, 1958, but before August 30, 1959—** (SR 422A). No person may operate a turbine engine powered airplane along an intended route unless he complies with either of the following: - (1) There is no place along the intended track that is more than 90 minutes (with all engines operating at cruising power) from an airport that meets the requirements of [§ 121.197](/cfr/14/121.197.md). - (2) Its weight, according to the two-engine-inoperative, en route, net flight path data in the Airplane Flight Manual, allows the airplane to fly from the point where the two engines are assumed to fail simultaneously to an airport that meets the requirements of [§ 121.197](/cfr/14/121.197.md), with a net flight path (considering the ambient temperatures anticipated along the track) having a positive slope at an altitude of at least 1,000 feet above all terrain and obstructions within 5 miles on each side of the intended track, or at an altitude of 2,000 feet, whichever is higher. - (c) **Aircraft certificated after August 29, 1959—** (SR 422B). No person may operate a turbine engine powered airplane along an intended route unless he complies with either of the following: - (1) There is no place along the intended track that is more than 90 minutes (with all engines operating at cruising power) from an airport that meets the requirements of [§ 121.197](/cfr/14/121.197.md). - (2) Its weight, according to the two-engine inoperative, en route, net flight path data in the Airplane Flight Manual, allows the airplane to fly from the point where the two engines are assumed to fail simultaneously to an airport that meets the requirements of [§ 121.197](/cfr/14/121.197.md), with the net flight path (considering the ambient temperatures anticipated along the track) clearing vertically by at least 2,000 feet all terrain and obstructions within five statute miles (4.34 nautical miles) on each side of the intended track. For the purposes of this subparagraph, it is assumed that— - (i) The two engines fail at the most critical point en route; - (ii) The net flight path has a positive slope at 1,500 feet above the airport where the landing is assumed to be made after the engines fail; - (iii) Fuel jettisoning will be approved if the certificate holder shows that the crew is properly instructed, that the training program is adequate, and that all other precautions are taken to ensure a safe procedure; - (iv) The airplane's weight at the point where the two engines are assumed to fail provides enough fuel to continue to the airport, to arrive at an altitude of at least 1,500 feet directly over the airport, and thereafter to fly for 15 minutes at cruise power or thrust, or both; and - (v) The consumption of fuel and oil after the engine failure is the same as the consumption that is allowed for in the net flight path data in the Airplane Flight Manual. # §121.195. Airplanes: Turbine engine powered: Landing limitations: Destination airports. - (a) No person operating a turbine engine powered airplane may take off that airplane at such a weight that (allowing for normal consumption of fuel and oil in flight to the destination or alternate airport) the weight of the airplane on arrival would exceed the landing weight set forth in the Airplane Flight Manual for the elevation of the destination or alternate airport and the ambient temperature anticipated at the time of landing. - (b) Except as provided in paragraph [(c)](#c), [(d)](#d), or [(e)](#e) of this section, no person operating a turbine engine powered airplane may take off that airplane unless its weight on arrival, allowing for normal consumption of fuel and oil in flight (in accordance with the landing distance set forth in the Airplane Flight Manual for the elevation of the destination airport and the wind conditions anticipated there at the time of landing), would allow a full stop landing at the intended destination airport within 60 percent of the effective length of each runway described below from a point 50 feet above the intersection of the obstruction clearance plane and the runway. For the purpose of determining the allowable landing weight at the destination airport the following is assumed: - (1) **The airplane is landed on the most favorable runway and in the most favorable direction, in still air.** - (2) The airplane is landed on the most suitable runway considering the probable wind velocity and direction and the ground handling characteristics of the airplane, and considering other conditions such as landing aids and terrain. - (c) A turbopropeller powered airplane that would be prohibited from being taken off because it could not meet the requirements of [paragraph (b)(2)](#b-2) of this section, may be taken off if an alternate airport is specified that meets all the requirements of this section except that the airplane can accomplish a full stop landing within 70 percent of the effective length of the runway. - (d) Unless, based on a showing of actual operating landing techniques on wet runways, a shorter landing distance (but never less than that required by [paragraph (b)](#b) of this section) has been approved for a specific type and model airplane and included in the Airplane Flight Manual, no person may takeoff a turbojet powered airplane when the appropriate weather reports and forecasts, or a combination thereof, indicate that the runways at the destination airport may be wet or slippery at the estimated time of arrival unless the effective runway length at the destination airport is at least 115 percent of the runway length required under [paragraph (b)](#b) of this section. - (e) A turbojet powered airplane that would be prohibited from being taken off because it could not meet the requirements of [paragraph (b)(2)](#b-2) of this section may be taken off if an alternate airport is specified that meets all the requirements of [paragraph (b)](#b) of this section. # §121.197. Airplanes: Turbine engine powered: Landing limitations: Alternate airports. No person may list an airport as an alternate airport in a dispatch or flight release for a turbine engine powered airplane unless (based on the assumptions in [§ 121.195 (b)](/cfr/14/121.195.md?p=b)) that airplane at the weight anticipated at the time of arrival can be brought to a full stop landing within 70 percent of the effective length of the runway for turbopropeller powered airplanes and 60 percent of the effective length of the runway for turbojet powered airplanes, from a point 50 feet above the intersection of the obstruction clearance plane and the runway. In the case of an alternate airport for departure, as provided in [§ 121.617](/cfr/14/121.617.md), allowance may be made for fuel jettisoning in addition to normal consumption of fuel and oil when determining the weight anticipated at the time of arrival.