523 

Federal Aviation Administration, DOT 

Pt. 135, App. A 

the control from the normal engine oper-
ating range. 

52. 

Reverse thrust controls. 

For turbo-

propeller powered airplanes, the propeller re-
verse thrust controls must have a means to 
prevent their inadvertent operation. The 
means must have a positive lock or stop at 
the idle position and must require a separate 
and distinct operation by the crew to dis-
place the control from the flight regime. 

53. 

Engine ignition systems. 

Each turbo-

propeller airplane ignition system must be 
considered an essential electrical load. 

54. 

Powerplant accessories. 

The powerplant 

accessories must meet FAR 23.1163, and if 
the continued rotation of any accessory re-
motely driven by the engine is hazardous 
when malfunctioning occurs, there must be 
means to prevent rotation without inter-
fering with the continued operation of the 
engine. 

Powerplant Fire Protection 

55. 

Fire detector system. 

For turbopropeller 

powered airplanes, the following apply: 

(a) There must be a means that ensures 

prompt detection of fire in the engine com-
partment. An overtemperature switch in 
each engine cooling air exit is an acceptable 
method of meeting this requirement. 

(b) Each fire detector must be constructed 

and installed to withstand the vibration, in-
ertia, and other loads to which it may be 
subjected in operation. 

(c) No fire detector may be affected by any 

oil, water, other fluids, or fumes that might 
be present. 

(d) There must be means to allow the flight 

crew to check, in flight, the functioning of 
each fire detector electric circuit. 

(e) Wiring and other components of each 

fire detector system in a fire zone must be at 
least fire resistant. 

56. 

Fire protection, cowling and nacelle skin. 

For reciprocating engine powered airplanes, 
the engine cowling must be designed and 
constructed so that no fire originating in the 
engine compartment can enter either 
through openings or by burn through, any 
other region where it would create addi-
tional hazards. 

57. 

Flammable fluid fire protection. 

If flam-

mable fluids or vapors might be liberated by 
the leakage of fluid systems in areas other 
than engine compartments, there must be 
means to— 

(a) Prevent the ignition of those fluids or 

vapors by any other equipment; or 

(b) Control any fire resulting from that ig-

nition. 

Equipment 

58. 

Powerplant instruments. 

(a) The fol-

lowing are required for turbopropeller air-
planes: 

(1) The instruments required by FAR 

23.1305 (a) (1) through (4), (b) (2) and (4). 

(2) A gas temperature indicator for each 

engine. 

(3) Free air temperature indicator. 
(4) A fuel flowmeter indicator for each en-

gine. 

(5) Oil pressure warning means for each en-

gine. 

(6) A torque indicator or adequate means 

for indicating power output for each engine. 

(7) Fire warning indicator for each engine. 
(8) A means to indicate when the propeller 

blade angle is below the low-pitch position 
corresponding to idle operation in flight. 

(9) A means to indicate the functioning of 

the ice protection system for each engine. 

(b) For turbopropeller powered airplanes, 

the turbopropeller blade position indicator 
must begin indicating when the blade has 
moved below the flight low-pitch position. 

(c) The following instruments are required 

for reciprocating engine powered airplanes: 

(1) The instruments required by FAR 

23.1305. 

(2) A cylinder head temperature indicator 

for each engine. 

(3) A manifold pressure indicator for each 

engine. 

Systems and Equipments 

General 

59. 

Function and installation. 

The systems 

and equipment of the airplane must meet 
FAR 23.1301, and the following: 

(a) Each item of additional installed equip-

ment must— 

(1) Be of a kind and design appropriate to 

its intended function; 

(2) Be labeled as to its identification, func-

tion, or operating limitations, or any appli-
cable combination of these factors, unless 
misuse or inadvertent actuation cannot cre-
ate a hazard; 

(3) Be installed according to limitations 

specified for that equipment; and 

(4) Function properly when installed. 
(b) Systems and installations must be de-

signed to safeguard against hazards to the 
aircraft in the event of their malfunction or 
failure. 

(c) Where an installation, the functioning 

of which is necessary in showing compliance 
with the applicable requirements, requires a 
power supply, that installation must be con-
sidered an essential load on the power sup-
ply, and the power sources and the distribu-
tion system must be capable of supplying the 
following power loads in probable operation 
combinations and for probable durations: 

(1) All essential loads after failure of any 

prime mover, power converter, or energy 
storage device. 

(2) All essential loads after failure of any 

one engine on two-engine airplanes. 

VerDate Sep<11>2014 

08:20 May 17, 2019

Jkt 247048

PO 00000

Frm 00533

Fmt 8010

Sfmt 8002

Y:\SGML\247048.XXX

247048