494 

14 CFR Ch. I (1–1–24 Edition) 

§ 27.67 

(ii) With the landing gear retracted; 

and 

(iii) For the weights, altitudes, and 

temperatures for which certification is 
requested; and 

(2) The climb gradient, at the rate of 

climb determined in accordance with 
paragraph (a)(1) of this section, must 
be either— 

(i) At least 1:10 if the horizontal dis-

tance required to take off and climb 
over a 50-foot obstacle is determined 
for each weight, altitude, and tempera-
ture within the range for which certifi-
cation is requested; or 

(ii) At least 1:6 under standard sea 

level conditions. 

(b) Each helicopter must meet the 

following requirements: 

(1) V

Y

must be determined— 

(i) For standard sea level conditions; 
(ii) At maximum weight; and 
(iii) With maximum continuous 

power on each engine. 

(2) The steady rate of climb must be 

determined— 

(i) At the climb speed selected by the 

applicant at or below V

NE

; 

(ii) Within the range from sea level 

up to the maximum altitude for which 
certification is requested; 

(iii) For the weights and tempera-

tures that correspond to the altitude 
range set forth in paragraph (b)(2)(ii) of 
this section and for which certification 
is requested; and 

(iv) With maximum continuous power 

on each engine. 

(Secs. 313(a), 601, 603, 604, and 605 of the Fed-
eral Aviation Act of 1958 (49 U.S.C. 1354(a), 
1421, 1423, 1424, and 1425); and sec. 6(c) of the 
Dept. of Transportation Act (49 U.S.C. 
1655(c))) 

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as 
amended by Amdt. 27–14, 43 FR 2324, Jan. 16, 
1978; Amdt. 27–33, 61 FR 21907, May 10, 1996] 

§ 27.67

Climb: one engine inoperative. 

For multiengine helicopters, the 

steady rate of climb (or descent), at 

V

y

 

(or at the speed for minimum rate of 
descent), must be determined with— 

(a) Maximum weight; 
(b) The critical engine inoperative 

and the remaining engines at either— 

(1) Maximum continuous power and, 

for helicopters for which certification 
for the use of 30-minute OEI power is 
requested, at 30-minute OEI power; or 

(2) Continuous OEI power for heli-

copters for which certification for the 
use of continuous OEI power is re-
quested. 

(Secs. 313(a), 601, 603, 604, and 605 of the Fed-
eral Aviation Act of 1958 (49 U.S.C. 1354(a), 
1421, 1423, 1424, and 1425); and sec. 6(c) of the 
Dept. of Transportation Act (49 U.S.C. 
1655(c))) 

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as 
amended by Amdt. 27–23, 53 FR 34210, Sept. 2, 
1988] 

§ 27.71

Autorotation performance. 

For single-engine helicopters and 

multiengine helicopters that do not 
meet the Category A engine isolation 
requirements of Part 29 of this chapter, 
the minimum rate of descent airspeed 
and the best angle-of-glide airspeed 
must be determined in autorotation 
at— 

(a) Maximum weight; and 
(b) Rotor speed(s) selected by the ap-

plicant. 

[Amdt. 27–21, 49 FR 44433, Nov. 6, 1984] 

§ 27.75

Landing. 

(a) The rotorcraft must be able to be 

landed with no excessive vertical accel-
eration, no tendency to bounce, nose 
over, ground loop, porpoise, or water 
loop, and without exceptional piloting 
skill or exceptionally favorable condi-
tions, with— 

(1) Approach or autorotation speeds 

appropriate to the type of rotorcraft 
and selected by the applicant; 

(2) The approach and landing made 

with— 

(i) Power off, for single engine rotor-

craft and entered from steady state 
autorotation; or 

(ii) One-engine inoperative (OEI) for 

multiengine rotorcraft, with each oper-
ating engine within approved operating 
limitations, and entered from an estab-
lished OEI approach. 

(b) Multiengine rotorcraft must be 

able to be landed safely after complete 
power failure under normal operating 
conditions. 

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as 
amended by Amdt. 27–14, 43 FR 2324, Jan. 16, 
1978; Amdt. 27–44, 73 FR 10999, Feb. 29, 2008] 

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