542
14 CFR Ch. I (1–1–24 Edition)
§ 27.1093
from entering the engine intake sys-
tem; and
(2) The air inlet ducts must be lo-
cated or protected so as to minimize
the ingestion of foreign matter during
takeoff, landing, and taxiing.
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–2, 33 FR 964, Jan. 26,
1968; Amdt. 27–23, 53 FR 34214, Sept. 2, 1988]
§ 27.1093
Induction system icing pro-
tection.
(a)
Reciprocating engines. Each recip-
rocating engine air induction system
must have means to prevent and elimi-
nate icing. Unless this is done by other
means, it must be shown that, in air
free of visible moisture at a tempera-
ture of 30 degrees F., and with the en-
gines at 75 percent of maximum contin-
uous power—
(1) Each rotorcraft with sea level en-
gines using conventional venturi car-
buretors has a preheater that can pro-
vide a heat rise of 90 degrees F.;
(2) Each rotorcraft with sea level en-
gines using carburetors tending to pre-
vent icing has a sheltered alternate
source of air, and that the preheat sup-
plied to the alternate air intake is not
less than that provided by the engine
cooling air downstream of the cyl-
inders;
(3) Each rotorcraft with altitude en-
gines using conventional venturi car-
buretors has a preheater capable of
providing a heat rise of 120 degrees F.;
and
(4) Each rotorcraft with altitude en-
gines using carburetors tending to pre-
vent icing has a preheater that can
provide a heat rise of—
(i) 100 degrees F.; or
(ii) If a fluid deicing system is used,
at least 40 degrees F.
(b)
Turbine engine. (1) It must be
shown that each turbine engine and its
air inlet system can operate through-
out the flight power range of the en-
gine (including idling)—
(i) Without accumulating ice on en-
gine or inlet system components that
would adversely affect engine oper-
ation or cause a serious loss of power
under the icing conditions specified in
appendix C of Part 29 of this chapter;
and
(ii) In snow, both falling and blowing,
without adverse effect on engine oper-
ation, within the limitations estab-
lished for the rotorcraft.
(2) Each turbine engine must idle for
30 minutes on the ground, with the air
bleed available for engine icing protec-
tion at its critical condition, without
adverse effect, in an atmosphere that is
at a temperature between 15
°
and 30
°
F
(between
¥
9
°
and
¥
1
°
C) and has a liq-
uid water content not less than 0.3
gram per cubic meter in the form of
drops having a mean effective diameter
not less than 20 microns, followed by
momentary operation at takeoff power
or thrust. During the 30 minutes of idle
operation, the engine may be run up
periodically to a moderate power or
thrust setting in a manner acceptable
to the Administrator.
(c)
Supercharged reciprocating engines.
For each engine having superchargers
to pressurize the air before it enters
the carburetor, the heat rise in the air
caused by that supercharging at any
altitude may be utilized in determining
compliance with paragraph (a) of this
section if the heat rise utilized is that
which will be available, automatically,
for the applicable altitude and oper-
ating condition because of super-
charging.
(Secs. 313(a), 601, and 603, 72 Stat. 752, 775, 49
U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49
U.S.C. 1655(c))
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–11, 41 FR 55470, Dec. 20,
1976; Amdt. 27–12, 42 FR 15045, Mar. 17, 1977;
Amdt. 27–20, 49 FR 6849, Feb. 23, 1984; Amdt.
27–23, 53 FR 34214, Sept. 2, 1988]
E
XHAUST
S
YSTEM
§ 27.1121
General.
For each exhaust system—
(a) There must be means for thermal
expansion of manifolds and pipes;
(b) There must be means to prevent
local hot spots;
(c) Exhaust gases must discharge
clear of the engine air intake, fuel sys-
tem components, and drains;
(d) Each exhaust system part with a
surface hot enough to ignite flammable
fluids or vapors must be located or
shielded so that leakage from any sys-
tem carrying flammable fluids or va-
pors will not result in a fire caused by
impingement of the fluids or vapors on
VerDate Sep<11>2014
09:06 Jun 28, 2024
Jkt 262046
PO 00000
Frm 00552
Fmt 8010
Sfmt 8010
Y:\SGML\262046.XXX
262046
jspears on DSK121TN23PROD with CFR
543
Federal Aviation Administration, DOT
§ 27.1143
any part of the exhaust system includ-
ing shields for the exhaust system;
(e) Exhaust gases may not impair
pilot vision at night due to glare;
(f) If significant traps exist, each tur-
bine engine exhaust system must have
drains discharging clear of the rotor-
craft, in any normal ground and flight
attitudes, to prevent fuel accumulation
after the failure of an attempted en-
gine start;
(g) Each exhaust heat exchanger
must incorporate means to prevent
blockage of the exhaust port after any
internal heat exchanger failure.
(Secs. 313(a), 601, and 603, 72 Stat. 752, 775, 49
U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49
U.S.C. 1655(c))
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–12, 42 FR 15045, Mar. 17,
1977]
§ 27.1123
Exhaust piping.
(a) Exhaust piping must be heat and
corrosion resistant, and must have pro-
visions to prevent failure due to expan-
sion by operating temperatures.
(b) Exhaust piping must be supported
to withstand any vibration and inertia
loads to which it would be subjected in
operations.
(c) Exhaust piping connected to com-
ponents between which relative motion
could exist must have provisions for
flexibility.
[Amdt. 27–11, 41 FR 55470, Dec. 20, 1976]
P
OWERPLANT
C
ONTROLS AND
A
CCESSORIES
§ 27.1141
Powerplant controls: general.
(a) Powerplant controls must be lo-
cated and arranged under § 27.777 and
marked under § 27.1555.
(b) Each flexible powerplant control
must be approved.
(c) Each control must be able to
maintain any set position without—
(1) Constant attention; or
(2) Tendency to creep due to control
loads or vibration.
(d) Controls of powerplant valves re-
quired for safety must have—
(1) For manual valves, positive stops
or in the case of fuel valves suitable
index provisions, in the open and closed
position; and
(2) For power-assisted valves, a
means to indicate to the flight crew
when the valve—
(i) Is in the fully open or fully closed
position; or
(ii) Is moving between the fully open
and fully closed position.
(e) For turbine engine powered rotor-
craft, no single failure or malfunction,
or probable combination thereof, in
any powerplant control system may
cause the failure of any powerplant
function necessary for safety.
(Secs. 313(a), 601, and 603, 72 Stat. 752, 775, 49
U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49
U.S.C. 1655(c))
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–12, 42 FR 15045, Mar. 17,
1977; Amdt. 27–23, 53 FR 34214, Sept. 2, 1988;
Amdt. 27–33, 61 FR 21907, May 10, 1996]
§ 27.1143
Engine controls.
(a) There must be a separate power
control for each engine.
(b) Power controls must be grouped
and arranged to allow—
(1) Separate control of each engine;
and
(2) Simultaneous control of all en-
gines.
(c) Each power control must provide
a positive and immediately responsive
means of controlling its engine.
(d) If a power control incorporates a
fuel shutoff feature, the control must
have a means to prevent the inad-
vertent movement of the control into
the shutoff position. The means must—
(1) Have a positive lock or stop at the
idle position; and
(2) Require a separate and distinct
operation to place the control in the
shutoff position.
(e) For rotorcraft to be certificated
for a 30-second OEI power rating, a
means must be provided to automati-
cally activate and control the 30-sec-
ond OEI power and prevent any engine
from exceeding the installed engine
limits associated with the 30-second
OEI power rating approved for the
rotorcraft.
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–11, 41 FR 55470, Dec. 20,
1976; Amdt. 27–23, 53 FR 34214, Sept. 2, 1988;
Amdt. 27–29, 59 FR 47767, Sept. 16, 1994]
VerDate Sep<11>2014
09:06 Jun 28, 2024
Jkt 262046
PO 00000
Frm 00553
Fmt 8010
Sfmt 8010
Y:\SGML\262046.XXX
262046
jspears on DSK121TN23PROD with CFR