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Federal Aviation Administration, DOT 

§ 27.1505 

this section and the requirements for 
cockpit voice recorders under this part 
are met. 

[Amdt. 27–22, 53 FR 26144, July 11, 1988, as 
amended by Amdt. 27–43, 73 FR 12564, Mar. 7, 
2008; 74 FR 32800, July 9, 2009; Amdt. 27–45, 75 
FR 17045, Apr. 5, 2010] 

§ 27.1461

Equipment containing high 

energy rotors. 

(a) Equipment containing high en-

ergy rotors must meet paragraph (b), 
(c), or (d) of this section. 

(b) High energy rotors contained in 

equipment must be able to withstand 
damage caused by malfunctions, vibra-
tion, abnormal speeds, and abnormal 
temperatures. In addition— 

(1) Auxiliary rotor cases must be able 

to contain damage caused by the fail-
ure of high energy rotor blades; and 

(2) Equipment control devices, sys-

tems, and instrumentation must rea-
sonably ensure that no operating limi-
tations affecting the integrity of high 
energy rotors will be exceeded in serv-

(c) It must be shown by test that 

equipment containing high energy ro-
tors can contain any failure of a high 
energy rotor that occurs at the highest 
speed obtainable with the normal speed 
control devices inoperative. 

(d) Equipment containing high en-

ergy rotors must be located where 
rotor failure will neither endanger the 
occupants nor adversely affect contin-
ued safe flight. 

[Amdt. 27–2, 33 FR 964, Jan. 26, 1968] 

Subpart G—Operating Limitations 

and Information 

§ 27.1501


(a) Each operating limitation speci-

fied in §§ 27.1503 through 27.1525 and 
other limitations and information nec-
essary for safe operation must be es-

(b) The operating limitations and 

other information necessary for safe 
operation must be made available to 

the crewmembers as prescribed in 
§§ 27.1541 through 27.1589. 

(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. 

[Amdt. 27–14, 43 FR 2325, Jan. 16, 1978] 






§ 27.1503

Airspeed limitations: general. 

(a) An operating speed range must be 


(b) When airspeed limitations are a 

function of weight, weight distribution, 
altitude, rotor speed, power, or other 
factors, airspeed limitations cor-
responding with the critical combina-
tions of these factors must be estab-

§ 27.1505

Never-exceed speed. 

(a) The never-exceed speed, V



be established so that it is— 

(1) Not less than 40 knots (CAS); and 
(2) Not more than the lesser of— 
(i) 0.9 times the maximum forward 

speeds established under § 27.309; 

(ii) 0.9 times the maximum speed 

shown under §§ 27.251 and 27.629; or 

(iii) 0.9 times the maximum speed 

substantiated for advancing blade tip 
mach number effects. 

(b) V


may vary with altitude, 

r.p.m., temperature, and weight, if— 

(1) No more than two of these vari-

ables (or no more than two instru-
ments integrating more than one of 
these variables) are used at one time; 

(2) The ranges of these variables (or 

of the indications on instruments inte-
grating more than one of these vari-
ables) are large enough to allow an 
operationally practical and safe vari-
ation of V


(c) For helicopters, a stabilized 

power-off V


denoted as V



off) may be established at a speed less 
than V


established pursuant to para-

graph (a) of this section, if the fol-
lowing conditions are met: 

(1) V


(power-off) is not less than a 

speed midway between the power-on 


and the speed used in meeting the 

requirements of— 

(i) § 27.65(b) for single engine heli-

copters; and 

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