§ 27.1305 Powerplant instruments. The following are the required powerplant instruments: ( a ) A carburetor air temperature indicator, for each engine having a preheater that can provide a heat rise in excess of 60 °F.
( b ) A cylinder head temperature indicator, for each— ( 1 ) Air cooled engine;
( 2 ) Rotorcraft with cooling shutters; and
( 3 ) Rotorcraft for which compliance with § 27.1043 is shown in any condition other than the most critical flight condition with respect to cooling.
( c ) A fuel pressure indicator, for each pump-fed engine.
( d ) A fuel quantity indicator, for each fuel tank.
( e ) A means to indicate manifold pressure for each altitude engine.
( f ) An oil temperature warning device to indicate when the temperature exceeds a safe value in each main rotor drive gearbox (including any gearboxes essential to rotor phasing) having an oil system independent of the engine oil system.
( g ) An oil pressure warning device to indicate when the pressure falls below a safe value in each pressure-lubricated main rotor drive gearbox (including any gearboxes essential to rotor phasing) having an oil system independent of the engine oil system.
( h ) An oil pressure indicator for each engine.
( i ) An oil quantity indicator for each oil tank.
( j ) An oil temperature indicator for each engine.
( k ) A means to indicate the r.p.m. of each engine and at least one tachometer, as applicable, for: ( 1 ) The r.p.m. of the single main rotor;
( 2 ) The common r.p.m. of any main rotors whose speeds cannot vary appreciably with respect to each other; or
( 3 ) The r.p.m. of each main rotor whose speed can vary appreciably with respect to that of another main rotor.
( l ) A low fuel warning device for each fuel tank which feeds an engine. This device must— ( 1 ) Provide a warning to the flightcrew when approximately 10 minutes of usable fuel remains in the tank; and
( 2 ) Be independent of the normal fuel quantity indicating system.
( m ) Means to indicate to the flightcrew the failure of any fuel pump installed to show compliance with § 27.955.
( n ) A means to indicate the gas temperature for each turbine engine.
( o ) A means to enable the pilot to determine the torque of each turbine engine, if a torque limitation is established for that engine under § 27.1521(e).
( p ) For each turbine engine, an indicator to indicate the functioning of the powerplant ice protection system.
( q ) An indicator for the fuel filter required by § 27.997 to indicate the occurrence of contamination of the filter at the degree established by the applicant in compliance with § 27.955.
( r ) For each turbine engine, a warning means for the oil strainer or filter required by § 27.1019, if it has no bypass, to warn the pilot of the occurrence of contamination of the strainer or filter before it reaches the capacity established in accordance with § 27.1019(a)(2).
( s ) An indicator to indicate the functioning of any selectable or controllable heater used to prevent ice clogging of fuel system components.
( t ) For rotorcraft for which a 30-second/2-minute OEI power rating is requested, a means must be provided to alert the pilot when the engine is at the 30-second and the 2-minute OEI power levels, when the event begins, and when the time interval expires.
( u ) For each turbine engine utilizing 30-second/2-minute OEI power, a device or system must be provided for use by ground personnel which— ( 1 ) Automatically records each usage and duration of power at the 30-second and 2-minute OEI levels;
( 2 ) Permits retrieval of the recorded data;
( 3 ) Can be reset only by ground maintenance personnel; and
( 4 ) Has a means to verify proper operation of the system or device.
( v ) Warning or caution devices to signal to the flight crew when ferromagnetic particles are detected by the chip detector required by § 27.1337(e).
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-9, 39 FR 35462, Oct. 1, 1974; Amdt. 27-23, 53 FR 34214, Sept. 2, 1988; Amdt. 27-29, 59 FR 47767, Sept. 16, 1994; Amdt. 27-37, 64 FR 45095, Aug. 18, 1999; 64 FR 47563, Aug. 31, 1999; Amdt. 27-51, 88 FR 8737, Feb. 10, 2023]