[Code of Federal Regulations]

[Title 14, Volume 1]

[Revised as of January 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 14CFR23.51]



[Page 185-186]

 

                     TITLE 14--AERONAUTICS AND SPACE

 

CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION

 

PART 23_AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND 

COMMUTER CATEGORY AIRPLANES--Table of Contents

 

                            Subpart B_Flight

 

Sec. 23.51  Takeoff speeds.



    (a) For normal, utility, and acrobatic category airplanes, rotation 

speed, VR, is the speed at which the pilot makes a control 

input, with the intention of lifting the airplane out of contact with 

the runway or water surface.

    (1) For multiengine landplanes, VR, must not be less than 

the greater of 1.05 VMC; or 1.10 VS1;

    (2) For single-engine landplanes, VR, must not be less 

than VS1; and

    (3) For seaplanes and amphibians taking off from water, 

VR, may be any speed that is shown to be safe under all 

reasonably expected conditions, including turbulence and complete 

failure of the critical engine.

    (b) For normal, utility, and acrobatic category airplanes, the speed 

at 50 feet above the takeoff surface level must not be less than:

    (1) or multiengine airplanes, the highest of--

    (i) A speed that is shown to be safe for continued flight (or 

emergency landing, if applicable) under all reasonably expected 

conditions, including turbulence and complete failure of the critical 

engine;

    (ii) 1.10 VMC; or

    (iii) 1.20 VS1.

    (2) For single-engine airplanes, the higher of--

    (i) A speed that is shown to be safe under all reasonably expected 

conditions, including turbulence and complete engine failure; or

    (ii) 1.20 VS1.

    (c) For commuter category airplanes, the following apply:

    (l) V1 must be established in relation to VEF 

as follows:

    (i) VEF is the calibrated airspeed at which the critical 

engine is assumed to fail. VEF must be selected by the 

applicant but must not be less than 1.05 VMC determined under 

Sec. 23.149(b) or, at the option of the applicant, not less than 

VMCG determined under Sec. 23.149(f).

    (ii) The takeoff decision speed, V1, is the calibrated 

airspeed on the ground at which, as a result of engine failure or other 

reasons, the pilot is assumed to have made a decision to continue or 

discontinue the takeoff. The takeoff decision speed, V1, must 

be selected by the applicant but must not be less than VEF 

plus the speed gained with the critical engine inoperative during the 

time interval between the instant at which the critical engine is failed 

and the instant at which the pilot recognizes and reacts to the engine 

failure, as indicated by the pilot's application of the first retarding 

means during the accelerate-stop determination of Sec. 23.55.

    (2) The rotation speed, VR, in terms of calibrated 

airspeed, must be selected



[[Page 186]]



by the applicant and must not be less than the greatest of the 

following:

    (i) V1;

    (ii) 1.05 VMC determined under Sec. 23.149(b);

    (iii) 1.10 VS1; or

    (iv) The speed that allows attaining the initial climb-out speed, 

V2, before reaching a height of 35 feet above the takeoff 

surface in accordance with Sec. 23.57(c)(2).

    (3) For any given set of conditions, such as weight, altitude, 

temperature, and configuration, a single value of VR must be 

used to show compliance with both the one-engine-inoperative takeoff and 

all-engines-operating takeoff requirements.

    (4) The takeoff safety speed, V2, in terms of calibrated 

airspeed, must be selected by the applicant so as to allow the gradient 

of climb required in Sec. 23.67 (c)(1) and (c)(2) but mut not be less 

than 1.10 VMC or less than 1.20 VS1.

    (5) The one-engine-inoperative takeoff distance, using a normal 

rotation rate at a speed 5 knots less than VR, established in 

accordance with paragraph (c)(2) of this section, must be shown not to 

exceed the corresponding one-engine-inoperative takeoff distance, 

determined in accordance with Sec. 23.57 and Sec. 23.59(a)(1), using 

the established VR. The takeoff, otherwise performed in 

accordance with Sec. 23.57, must be continued safely from the point at 

which the airplane is 35 feet above the takeoff surface and at a speed 

not less than the established V2 minus 5 knots.

    (6) The applicant must show, with all engines operating, that marked 

increases in the scheduled takeoff distances, determined in accordance 

with Sec. 23.59(a)(2), do not result from over-rotation of the airplane 

or out-of-trim conditions.



[Doc. No. 27807, 61 FR 5184, Feb. 9, 1996]