569 

Federal Aviation Administration, DOT 

Pt. 27, App. C 

(i) The controllability and maneuver-

ability requirements in Subpart B of this 
part must be met throughout a practical 
flight envelope; 

(ii) The flight control, trim, and dynamic 

stability characteristics must not be im-
paired below a level needed to allow contin-
ued safe flight and landing; and 

(iii) The static longitudinal and static di-

rectional stability requirements of Subpart 
B must be met throughout a practical flight 
envelope. 

(b) The SAS must be designed so that it 

cannot create a hazardous deviation in flight 
path or produce hazardous loads on the heli-
copter during normal operation or in the 
event of malfunction or failure, assuming 
corrective action begins within an appro-
priate period of time. Where multiple sys-
tems are installed, subsequent malfunction 
conditions must be considered in sequence 
unless their occurrence is shown to be im-
probable. 

VIII. 

Equipment, systems, and installation. 

The basic equipment and installation must 
comply with §§ 29.1303, 29.1431, and 29.1433 
through Amendment 29–14, with the fol-
lowing exceptions and additions: 

(a) 

Flight and Navigation Instruments. 

(1) A 

magnetic gyro-stablized direction indicator 
instead of a gyroscopic direction indicator 
required by § 29.1303(h); and 

(2) A standby attitude indicator which 

meets the requirements of §§ 29.1303(g)(1) 
through (7) instead of a rate-of-turn indi-
cator required by § 29.1303(g). For two-pilot 
configurations, one pilot’s primary indicator 
may be designated for this purpose. If stand-
by batteries are provided, they may be 
charged from the aircraft electrical system 
if adequate isolation is incorporated. 

(b) 

Miscellaneous requirements. 

(1) Instru-

ment systems and other systems essential 
for IFR flight that could be adversely af-
fected by icing must be adequately protected 
when exposed to the continuous and inter-
mittent maximum icing conditions defined 
in appendix C of Part 29 of this chapter, 
whether or not the rotorcraft is certificated 
for operation in icing conditions. 

(2) There must be means in the generating 

system to automatically de-energize and dis-
connect from the main bus any power source 
developing hazardous overvoltage. 

(3) Each required flight instrument using a 

power supply (electric, vacuum, etc.) must 
have a visual means integral with the instru-
ment to indicate the adequacy of the power 
being supplied. 

(4) When multiple systems performing like 

functions are required, each system must be 
grouped, routed, and spaced so that physical 
separation between systems is provided to 
ensure that a single malfunction will not ad-
versely affect more than one system. 

(5) For systems that operate the required 

flight instruments at each pilot’s station— 

(i) Only the required flight instruments for 

the first pilot may be connected to that op-
erating system; 

(ii) Additional instruments, systems, or 

equipment may not be connected to an oper-
ating system for a second pilot unless provi-
sions are made to ensure the continued nor-
mal functioning of the required instruments 
in the event of any malfunction of the addi-
tional instruments, systems, or equipment 
which is not shown to be extremely improb-
able; 

(iii) The equipment, systems, and installa-

tions must be designed so that one display of 
the information essential to the safety of 
flight which is provided by the instruments 
will remain available to a pilot, without ad-
ditional crewmember action, after any single 
failure or combination of failures that is not 
shown to be extremely improbable; and 

(iv) For single-pilot configurations, instru-

ments which require a static source must be 
provided with a means of selecting an alter-
nate source and that source must be cali-
brated. 

IX. 

Rotorcraft Flight Manual. 

A Rotorcraft 

Flight Manual or Rotorcraft Flight Manual 
IFR Supplement must be provided and must 
contain— 

(a) 

Limitations. 

The approved IFR flight en-

velope, the IFR flightcrew composition, the 
revised kinds of operation, and the steepest 
IFR precision approach gradient for which 
the helicopter is approved; 

(b) 

Procedures. 

Required information for 

proper operation of IFR systems and the rec-
ommended procedures in the event of sta-
bility augmentation or electrical system 
failures; and 

(c) 

Performance. 

If V

YI

differs from V

Y

, 

climb performance at V

YI

and with maximum 

continuous power throughout the ranges of 
weight, altitude, and temperature for which 
approval is requested. 

X. Electrical and electronic system light-

ning protection. For regulations concerning 
lightning protection for electrical and elec-
tronic systems, see § 27.1316. 

[Amdt. 27–19, 48 FR 4389, Jan. 31, 1983, as 
amended by Amdt. 27–44, 73 FR 11000, Feb. 29, 
2008; Amdt. 27–46, 76 FR 33135, June 8, 2011] 

A

PPENDIX

C 

TO

P

ART

27—C

RITERIA FOR

 

C

ATEGORY

A 

C27.1

General. 

A small multiengine rotorcraft may not be 

type certificated for Category A operation 
unless it meets the design installation and 
performance requirements contained in this 
appendix in addition to the requirements of 
this part. 

C27.2

Applicable part 29 sections. The fol-

lowing sections of part 29 of this chapter 
must be met in addition to the requirements 
of this part: 

VerDate Sep<11>2014 

12:50 Apr 30, 2019

Jkt 247046

PO 00000

Frm 00579

Fmt 8010

Sfmt 8002

Y:\SGML\247046.XXX

247046

spaschal on DSK3GDR082PROD with CFR