(5) Heat exchangers or muffs shall incorporate no stagnant areas or liquid traps which would increase the possibility of ignition of flammable fluids or vapors which might be present in case of failure or malfunctioning of components carrying flammable fluids. (d) Exhaust heating of ventilating air. If an exhaust heat exchanger is used for heating ventilating air, a secondary heat exchanger shall be provided between the primary exhaust gas heat exchanger and the ventilating air system, unless it is demonstrated that other means used preclude harmful contamination of the ventilating air. (e) Exhaust driven turbo-superchargers. (1) Exhaust driven turbines shall be of an approved type or shall be shown to be suitable for the particular application. They shall be installed and supported to assure their safe operation between normal inspection and overhaul periods. (2) Provision for expansion and flexibility shall be made between exhaust conduits and the turbine. (3) Provision shall be made for lubrication of the turbine and for cooling of those turbine parts where the temperatures are critical. (4) Means shall be provided so that, in the event of malfunctioning of the normal turbo-supercharger control system, the turbine speed will not be greater than its maximum allowable value. The components provided for this purpose shall be independent of the normal turbo-supercharger controls with the exception of the waste gate operating components themselves. [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F. R. 1096, Feb. 5, 1952] § 4b.467-1 Carbon monoxide detection (FAA policies which apply to § 4b.467 (a) (1) (d)). (a) Conditions for tests. Any acceptable carbon monoxide detection method may be used in demonstrating compliance with § 4b.467(a) (1) and (d), and with the ventilating requirements of § 4b.371. The tests should be conducted with the airplane's heater system in operation if there is any possibility of a system containing carbon monoxide. In aircraft employing thermal de-icing, tests should be conducted with the system operating at full capacity. (b) Configuration. Carbon monoxide tests should be conducted in the configurations that follow: (1) Power on level flight. Weight-Optional. C. G. position-Optional. Engines-Maximum continuous power. Wing flaps-Retracted. Cowl flaps-Appropriate for flight condition. (3) Power approach. Wing flaps-Approach position. (c) Test procedure and required data. The air should be sampled with a carbon monoxide indicator in front of cabin heater opening(s) with heat on and at representative passenger and crew locations. If the airplane does not have pressurization equipment installed, the air should be sampled at the above locations with the windows closed and also partially opened. If the airplane is equipped for pressurization, carbon monoxide indications should be taken when the cabin is pressurized and also unpressurized. [Supp. 24, 19 F. R. 4465, July 20, 1954] § 4b.467-2 Determination of exhaust gas interference with visibility (FAA policies which apply § 4b.467 (a) (5)). to The effects of exhaust gas interference with visibility should be observed during tests to demonstrate other night flying requirements. [Supp. 24, 19 F. R. 4466, July 20, 1954] POWERPLANT CONTROLS AND ACCESSORIES § 4b.470 Powerplant controls; general. The provisions of § 4b.353 shall be applicable to all powerplant controls with respect to location, grouping, and direction of motion, and the provisions of § 4b.737 shall be applicable to all powerplant controls with respect to marking. In addition all powerplant controls shall comply with the following. (a) Controls shall be so located that they cannot be inadvertently operated by personnel entering, leaving, or making normal movements in the cockpit. (b) Controls shall maintain any set position without constant attention by flight personnel. They shall not tend to creep due to control loads or vibration. (c) Flexible controls shall be of an approved type or shall be shown to be suitable for the particular application. (d) Controls shall have strength and rigidity to withstand operating loads without failure and without excessive deflection. § 4b.471 Throttle and A.D.I. system controls. (a) A separate throttle control shall be provided for each engine. Throttle controls shall be grouped and arranged to permit separate control of each engine and also simultaneous control of all engines. (b) Throttle controls shall afford a positive and immediately responsive means of controlling the engines. (c) If an antidetonant injection system is provided, the flow of ADI fluid shall be automatically controlled in relation to the amount of power produced by the engine. In addition to the automatic control, a separate control shall be provided for the ADI pumps. [Amdt. 4b-2, 15 F. R. 9185, Dec. 22, 1950, as amended by Amdt. 4b-8, 18 F. R. 2215, Apr. 18, 1953] § 4b.472 Ignition switches. (a) Ignition switches shall provide control for each ignition circuit on each engine. (b) Means shall be provided for quickly shutting off all ignition by the grouping of switches or by providing a master ignition control. (c) If a master ignition control is provided, a guard shall be incorporated to prevent inadvertent operation of the control. (c) The mixture controls shall be placed in a location accessible to both pilots, except where a separate flight engineer station with a control panel is provided, in which case the mixture controls shall be accessible to the flight engineer. [Amdt. 4b-2, 15 F. R. 9185, Dec. 22, 1950, as amended by Amdt. 4b-8, 18 F. R. 2215, Apr. 18, 1953] § 4b.474 Propeller controls. (a) Propeller speed and pitch controls. (1) A separate propeller speed and pitch control shall be provided for each propeller. The propeller speed and pitch controls shall be grouped and arranged to permit separate control of each propeller and also simultaneous control of all propellers. (2) The propeller speed and pitch controls shall provide for synchronization of all propellers. (See also § 4b.404.) (3) Propeller speed and pitch control(s) shall be placed to the right of the pilot's throttle and shall be at least 1 inch lower than the throttle controls. (b) Propeller feathering controls. (1) A separate propeller feathering control shall be provided for each propeller. (2) Propeller feathering controls shall be provided with means to prevent inadvertent operation. (3) If feathering is accomplished by movement of the propeller pitch or speed control lever, provision shall be made to prevent the movement of this control to the feathering position during normal operation. [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F. R. 1096, Feb. 5, 1952; Amdt. 4b-8, 18 F.R. 2215, Apr. 18, 1953; Amdt. 4b-6, 22 F.R. 5565, July 16, 1957] § 4b.474-11 Propeller feathering pump motors, intermittent duty type (FAA policies which apply to § 4b.474(b)). (a) An intermittent duty type motor' in the propeller feathering control system should automatically stop or be made to stop upon the completion of the feathering operation by any of the following means: (1) Installation of a pressure cutout switch in the feathering button holding coil circuit. 1 Appears as § 4.474-1 at 22 F. R. 6885. 'Intermittent duty type motors may fail if operated continuously for more than two minutes. (2) Installation of a timer switch in the feathering button holding coil circuit. (3) Manually interrupting the feathering pump circuit by pulling out the feathering button. In this arrangement a warning light should be installed in the pump circuit to illuminate while the pump motor is operating. The light may be either in the feathering button or adjacent to it. (b) Timer switches of either the mechanical or the thermal types are acceptable. [Supp. 33, 22 F. R. 6885, Aug. 27, 1957] § 4b.474a Reverse thrust controls. (a) Propeller reverse thrust controls shall incorporate a means to prevent their inadvertent movement to a reverse thrust position. The means provided shall incorporate a positive lock or stop at the flight idle position and shall require a separate and distinct operation by the crew in order to displace the control from the flight regime. (b) Turbojet reverse thrust controls shall incorporate a means to prevent their inadvertent movement to a reverse thrust position. The means provided shall incorporate a positive lock or stop at the flight idle position and shall require a separate and distinct operation by the crew in order to displace the control from the forward thrust regime. [Amdt. 4b-6, 22 F. R. 5565, July 16, 1957] § 4b.475 Fuel system controls. (See also § 4b.434.) (a) Fuel jettisoning system controls shall be provided with guards to prevent their inadvertent operation. (b) Fuel jettisoning system controls shall not be located in close proximity to fire extinguisher controls nor to any other controls intended to combat fire. §4b.476 Carburetor air preheat controls. Separate carburetor air preheat controls shall be provided to regulate the temperature of the carburetor air for each engine. § 4b.476a Supercharger controls. Supercharger controls shall be accessible to the pilots, except where a separate flight engineer station with a control panel is provided, in which case they shall be accessible to the flight engineer. [Amdt. 4b-8, 18 F. R. 2215, Apr. 19, 1953] § 4b.477 Powerplant accessories. (a) Engine mounted accessories shall be of a type approved for installation on the engine involved and shall utilize the provisions made on the engine for mounting. (b) Items of electrical equipment subject to arcing or sparking shall be installed to minimize the possibility of their contact with any flammable fluids or vapors which might be present in a free state. (c) If continued rotation of an engine-driven cabin supercharger or any remote accessory driven by the engine will constitute a hazard in case malfunctioning occurs, means shall be provided to prevent hazardous rotation of such accessory without interfering with the continued operation of the engine. (See also § 4b.371 (c).) NOTE: Hazardous rotation may involve consideration of mechanical damage or sustained air flows which may be dangerous under certain conditions. [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F. R. 1096, Feb. 5, 1952] § 4b.478 Engine ignition systems. (a) Battery ignition systems shall be supplemented with a generator which is automatically made available as an alternate source of electrical energy to permit continued engine operation in the event of the depletion of any battery. (b) The capacity of batteries and generators shall be sufficient to meet the simultaneous demands of the engine ignition system and the greatest demands of any airplane electrical system components which would draw electrical energy from the same source. (1) The design of the engine ignition system shall take into consideration the condition of an inoperative generator and the condition of a completely depleted battery when the generator is running at its normal operating speed. (2) If only one battery is provided the design of the engine ignition system shall take into consideration the condition in which the battery is completely depleted and the generator is operating at idling speed. (3) Portions of magneto ground wires for separate ignition circuits which lie on the engine side of the fire wall shall be installed, located, or protected so as to minimize the possibility of simultaneous failure of two or more wires as a result of mechanical damage, electrical faults, etc. (4) Ground wires for any engine shall not be routed through fire zones, except those associated with the engine which the wires serve, unless those portions of the wires which are located in such fire zones are fireproof or are protected against the possibility of damage by fire in a manner to render them fireproof. (See § 4b.472 for ignition switches.) (5) Ignition circuits shall be electrically independent of all other electrical circuits except circuits used for analyzing the operation of the ignition system. (c) Means shall be provided to warn flight personnel if malfunctioning of any part of the electrical system is causing the continuous discharging of a battery which is necessary for engine ignition. (See § 4b.472 for ignition switches.) [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F. R. 1096, Feb. 5, 1952] POWERPLANT FIRE PROTECTION § 4b.480 Designated fire zones. (a) Designated fire zones shall comprise the following regions: (1) Engine power section, (2) Engine accessory section, (3) Complete powerplant compartments in which no isolation is provided between the engine power section and the engine accessory section, (4) Auxiliary power unit compartments, (5) Fuel-burning heaters and other combustion equipment installations as defined by § 4b.386. NOTE: See also § 4b.385. (6) Compressor and accessory sections of turbine engines. (7) Combustor, turbine, and tail pipe sections of turbine engine installations which contain lines or components carrying flammable fluids or gases, except that the fire-extinguisher system specified in §4b.484 need not be provided for such sections if it is demonstrated that any fire occurring therein can be otherwise controlled. (b) Designated fire zones shall be protected from fire by compliance with § 4b.481 through 4b.490. (c) The nacelle area immediately behind the fire wall shall comply with the provisions of §§ 4b.385, 4b.463 (d), 4b.478 (b) (4), 4b.481 (c), 4b.482 through 4b.485 and 4b.489. If a retractable landing gear is located in this area, compliance with this paragraph is required only with the landing gear retracted. [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F. R. 1097, Feb. 5, 1952; Amdt. 4b-7, 17 F. R. 11631, Dec. 20, 1952; Amdt. 4b-2, 20 F.R. 5306, July 26, 1955; Amdt. 4b-6, 22 F.R. 5565, July 16, 1957] § 4b.481 Flammable fluids. (a) No tanks or reservoirs which are a part of a system containing flammable fluids or gases shall be located in designated fire zones except where the fluid contained, the design of the system, the materials used in the tank, the shut-off means, all connections, lines, and controls are such as to provide an equally high degree of safety. (b) Not less than one-half inch of clear air space shall be provided between any tank or reservoir and a fire wall or shroud isolating a designated fire zone. (c) If absorbent materials are located in proximity to flammable fluid system components which might be subject to leakage, such materials shall be covered or treated to prevent the absorption of hazardous quantities of fluids. [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-2, 20 F. R. 5306, July 26, 1955] § 4b.482 Shut-off means. (a) Means for each individual engine and for each individual fire zone specified in § 4b.480 (a) (4) and (5) shall be provided for shutting off or otherwise preventing hazardous quantities of fuel, oil, de-icer, and other flammable fluids from flowing into, within, or through any designated fire zone, except that means need not be provided to shut off flow in lines forming an integral part of an engine. Closing the fuel shutoff valve for any engine shall not make any of the fuel supply unavailable to the remaining engines. (b) Operation of the shutoff means shall not interfere with the subsequent emergency operation of other equipment, such as feathering the propeller. (c) The shut-off means shall be located outside of designated fire zones, unless an equally high degree of safety is otherwise provided (see § 4b.481). It shall be shown that no hazardous quantity of flammable fluid could drain into any designated fire zone after shuttingoff has been accomplished. (d) Provisions shall be made to guard against inadvertent operation of the shutoff means and to make it possible for the crew to reopen the shutoff means in flight after it has once been closed. [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F. R. 1097, Feb. 5, 1952] § 4b.483 Lines and fittings. (a) All lines and fittings carrying flammable fluids in designated fire zones shall be fire-resistant, except as otherwise provided in this section. If flexible hose is used, the assembly of hose and end fittings shall be of an approved type. The provisions of this paragraph need not apply to those lines and fittings which form an integral part of the engine. (b) Vent and drain lines and their fittings shall be subject to the provisions of paragraph (a) of this section unless a failure of such line or fitting will not result in, or add to, a fire hazard. [Amdt. 4b-11, 24 F.R. 7071, Sept. 1, 1959] § 4b.484 Fire extinguisher systems. (a) General. (1) Fire extinguisher systems shall be provided to serve all designated fire zones. This requirement shall be effective with respect to applications for type certificates in accordance with the provisions of § 4b.11(a). In addition, all other airplanes manufactured after June 30, 1954, shall comply with this requirement, unless the engine power section is completely isolated from the engine accessory section by a fireproof diaphragm complying with the provisions of § 4b.488 and unless the cowling and nacelle skin comply with the provisions of § 4b.487, in which case fire extinguisher systems need not be provided in the engine power section. NOTE: Induction systems for reciprocating engines are considered to be located in a designated fire zone, and therefore subject to the fire extinguisher protection provisions unless tests or experience with the particular type of induction and carburetion systems shows that fuel burning in the induction system passages is not likely to occur. (3) The fire-extinguishing system for a nacelle shall be capable of protecting simultaneously all zones of the nacelle for which protection is provided. (b) Fire extinguishing agents. (1) Extinguishing agents employed shall be methyl bromide, carbon dioxide, or any other agent which has been shown to provide equivalent extinguishing action. (2) If methyl bromide, carbon dioxide, or any other toxic extinguishing agent is employed, provision shall be made to prevent the entrance of harmful concentration of fluid or fluid vapors into any personnel compartments either due to leakage during normal operation of the airplane or as a result of discharging the fire extinguisher on the ground or in flight even though a defect may exist in the extinguishing system. Compliance with this requirement shall be demonstrated by appropriate tests. (3) If a methyl bromide system is provided, the containers shall be charged with a dry agent and shall be sealed by the fire extinguisher manufacturer or by any other party employing appropriate recharging equipment. (c) Extinguishing agent container pressure relief. Extinguisher agent containers shall be provided with a pressure relief to prevent bursting of the container due to excessive internal pressures. The following provisions shall apply. (1) The discharge line from the relief connection shall terminate outside the airplane in a location convenient for inspection on the ground. (2) An indicator shall be provided at the discharge end of the line to provide a visual indication when the container has discharged. (d) Extinguishing agent container compartment temperature. Under all conditions in which the airplane is intended for operation, the temperature range of the extinguishing agent containers shall be maintained to assure that the pressure in the containers can neither fall below the minimum necessary to provide an adequate rate of extinguisher agent discharge nor rise above a safe limit so that the system will not be prematurely discharged. (e) Fire-extinguishing system materials. Materials in the fire extinguishing system shall not react chemically with the extinguishing agent so as to constitute a hazard. All components of the fire extinguishing systems located |