557 

Federal Aviation Administration, DOT 

§ 27.1457 

§ 27.1419

Ice protection. 

(a) To obtain certification for flight 

into icing conditions, compliance with 
this section must be shown. 

(b) It must be demonstrated that the 

rotorcraft can be safely operated in the 
continuous maximum and intermittent 
maximum icing conditions determined 
under appendix C of Part 29 of this 
chapter within the rotorcraft altitude 
envelope. An analysis must be per-
formed to establish, on the basis of the 
rotorcraft’s operational needs, the ade-
quacy of the ice protection system for 
the various components of the rotor-
craft. 

(c) In addition to the analysis and 

physical evaluation prescribed in para-
graph (b) of this section, the effective-
ness of the ice protection system and 
its components must be shown by 
flight tests of the rotorcraft or its com-
ponents in measured natural atmos-
pheric icing conditions and by one or 
more of the following tests as found 
necessary to determine the adequacy of 
the ice protection system: 

(1) Laboratory dry air or simulated 

icing tests, or a combination of both, of 
the components or models of the com-
ponents. 

(2) Flight dry air tests of the ice pro-

tection system as a whole, or its indi-
vidual components. 

(3) Flight tests of the rotorcraft or 

its components in measured simulated 
icing conditions. 

(d) The ice protection provisions of 

this section are considered to be appli-
cable primarily to the airframe. Power-
plant installation requirements are 
contained in Subpart E of this part. 

(e) A means must be indentified or 

provided for determining the formation 
of ice on critical parts of the rotor-
craft. Unless otherwise restricted, the 
means must be available for nighttime 
as well as daytime operation. The 
rotorcraft flight manual must describe 
the means of determining ice forma-
tion and must contain information nec-
essary for safe operation of the rotor-
craft in icing conditions. 

[Amdt. 27–19, 48 FR 4389, Jan. 31, 1983] 

§ 27.1435

Hydraulic systems. 

(a) 

Design.  Each hydraulic system 

and its elements must withstand, with-

out yielding, any structural loads ex-
pected in addition to hydraulic loads. 

(b) 

Tests.  Each system must be sub-

stantiated by proof pressure tests. 
When proof tested, no part of any sys-
tem may fail, malfunction, or experi-
ence a permanent set. The proof load of 
each system must be at least 1.5 times 
the maximum operating pressure of 
that system. 

(c) 

Accumulators.  No hydraulic accu-

mulator or pressurized reservoir may 
be installed on the engine side of any 
firewall unless it is an integral part of 
an engine. 

§ 27.1457

Cockpit voice recorders. 

(a) Each cockpit voice recorder re-

quired by the operating rules of this 
chapter must be approved, and must be 
installed so that it will record the fol-
lowing: 

(1) Voice communications trans-

mitted from or received in the rotor-
craft by radio. 

(2) Voice communications of flight 

crewmembers on the flight deck. 

(3) Voice communications of flight 

crewmembers on the flight deck, using 
the rotorcraft’s interphone system. 

(4) Voice or audio signals identifying 

navigation or approach aids introduced 
into a headset or speaker. 

(5) Voice communications of flight 

crewmembers using the passenger loud-
speaker system, if there is such a sys-
tem, and if the fourth channel is avail-
able in accordance with the require-
ments of paragraph (c)(4)(ii) of this sec-
tion. 

(6) If datalink communication equip-

ment is installed, all datalink commu-
nications, using an approved data mes-
sage set. Datalink messages must be 
recorded as the output signal from the 
communications unit that translates 
the signal into usable data. 

(b) The recording requirements of 

paragraph (a)(2) of this section may be 
met: 

(1) By installing a cockpit-mounted 

area microphone located in the best po-
sition for recording voice communica-
tions originating at the first and sec-
ond pilot stations and voice commu-
nications of other crewmembers on the 
flight deck when directed to those sta-
tions; or 

VerDate Sep<11>2014 

09:06 Jun 28, 2024

Jkt 262046

PO 00000

Frm 00567

Fmt 8010

Sfmt 8010

Y:\SGML\262046.XXX

262046

jspears on DSK121TN23PROD with CFR