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(5) Fuel-burning heaters and other combustion equipment installations as defined by § 7.383.

(b) Designated fire zones shall be protected from fire by compliance with §§ 7.481 through 7.489.

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NOTE: For Category B rotorcraft, powerplant fire protection provisions are intended to insure that the main and auxiliary rotors and controls remain operable, that the essential rotorcraft structure remains intact, and that the passengers and crew are otherwise protected for a period of at least 5 minutes after the start of an engine fire to permit a controlled autorotative landing. § 7.481 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 and its supports, the shutoff means, all connections, lines, and controls are such as to provide an equally high degree of safety.

(b) Fuel tanks shall be isolated from the engines by a fire wall or shroud. Not less than one-half inch of clear airspace shall be provided between any tank or reservoir and a fire wall or shroud isolating a designated fire zone, unless other equivalent means are used to protect against heat transfer from the fire zone to the flammable fluid.

(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.

§ 7.482 Shutoff means.

(a) Means 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 specified in § 7.480 (a), except that means need not be provided to shut off flow in lines forming an integral part of an engine. Closing any fuel shutoff valve for any engine shall not affect more than the selected engine.

(1) Category A. It shall be shown that no hazardous quantity of flammable fluid could drain into any designated fire zone after shutting off has been accomplished. Closing the fuel shutoff valve for any engine shall not make any of the fuel supply unavailable to the remaining engines.

(2) Category B. In installations using engines of less than 500 cubic inches displacement, shutoff means need not be provided for engine oil systems.

(b) Operation of the shutoff means shall not interfere with the subsequent emergency operation of other equipment, such as declutching the engine from the rotor drive.

(c) The shutoff means shall be located outside of designated fire zones, unless an equally high degree of safety is otherwise provided (see § 7.481).

(d) Provision 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. § 7.483 Lines and fittings.

(a) All lines and fittings carrying flammable fluids in areas subject to engine fire conditions 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 shall 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. 7-4, 24 F.R. 7076, Sept. 1, 1959]

§ 7.484 Fire-extinguishing systems.

(a) General. (1) Fire-extinguishing systems shall be provided to serve all designated fire zones except that such systems need not be provided on Category B rotorcraft employing engines of 1,500 cubic inches or less displacement.

(2) On multiengine rotorcraft, the fire-extinguishing system, the quantity of extinguishing agent, and the rate of discharge shall be such as to provide two adequate discharges. It shall be possible to direct both discharges to any main engine installation. Individual "oneshot" systems shall be acceptable in the case of auxiliary power units, fuel-burning heaters, and other combustion equipment. On single-engine rotorcraft, the quantity of extinguishing agent and the rate of discharge shall be such as to provide one adequate discharge for the engine compartment.

(3) The fire-extinguishing system for a powerplant shall be capable of protect

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ing simultaneously all zones of the powerplant compartment 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 concentrations of fluid or fluid vapors into any personnel compartment either due to leakage during normal operation of the rotorcraft 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. Extinguishing 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 rotorcraft 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 rotorcraft 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 extinguishing 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 in

engine compartments shall be constructed of fireproof materials. § 7.485 Fire-detector systems.

Quick-acting fire detectors of an approved type shall be provided in all designated fire zones, except on Category B rotorcraft employing engines of 900 cubic inches or less displacement. The fire detectors shall be sufficient in number and location to assure prompt detection of fire in such zones. Fire detectors shall comply with the following provisions:

(a) Fire detectors shall be constructed and installed to assure their ability to resist without failure all vibration, inertia, and other loads to which they would be subjected in operation.

(b) Fire detectors shall be unaffected by exposure to oil, water, or other fluids or fumes which might be present.

(c) Means shall be provided to permit the crew to check in flight the functioning of the electrical circuit associated with the fire-detector system.

(d) Wiring and other components of the fire-detector systems which are located in engine compartments shall be of fire-resistant construction.

(e) Detector system components for any fire zone shall not pass through other fire zones, unless they are protected against the possibility of false warnings resulting from fires in zones through which they pass. This requirement shall not be applicable with respect to zones which are simultaneously protected by the same detector and extinguishing systems.

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Engines shall be isolated from personnel compartments by means of fire walls, shrouds, or other equivalent means. They shall be similarly isolated from the structure, controls, rotor mechanism, and other parts essential to controlled flight and landing of the rotorcraft, unless such parts are protected in accordance with the provisions of § 7.384. All auxiliary power units, fuel-burning heaters, and other combustion equipment which are intended for operation in flight shall be isolated from the remainder of the rotorcraft by means of fire walls, shrouds, or other equivalent means. In complying with the provisions of this section, account shall be taken of the probable path of a fire as affected by the air flow in

normal flight and in autorotation. The following shall apply:

(a) Fire walls and shrouds shall be constructed in such a manner that no hazardous quantity of air, fluids, or flame can pass from the engine compartment to other portions of the rotorcraft.

(b) All openings in the fire wall or shroud shall be sealed with close-fitting fireproof grommets, bushings, or firewall fittings.

(c) Fire walls and shrouds shall be constructed of fireproof material and shall be protected against corrosion. § 7.487

Cowling.

(a) Cowling or engine compartment covering shall be constructed and supported so as to make it capable of resisting all vibration, inertia, and air loads to which it would be subjected in operation.

(b) Cowling shall have drainage and ventilation provisions as prescribed in § 7.489.

(c) On rotorcraft equipped with a diaphragm complying with § 7.488, the parts of the accessory section cowling which might be subject to flame in the event of a fire in the engine power section of the powerplant shall be constructed of fireproof material and shall comply with the provisions of § 7.486.

(d) Those portions of the cowling or engine compartment covering which would be subjected to high temperatures due to their proximity to exhaust system parts or exhaust gas impingement shall be constructed of fireproof material.

(e) Category A: The rotorcraft shall be so designed and constructed that fire originating in any fire zone cannot enter, either through openings or by burning through external skin, into any other zone or region where such fire would create additional hazards. If the rotorcraft is provided with a retractable landing gear, this provision shall apply with the landing gear retracted. Fireproof materials shall be used for all skin areas which might be subjected to flame in the event of a fire originating in the engine power or accessory sections.

§ 7.488 Category A; engine accessory section diaphragm.

Unless equivalent protection can be shown by other means, a diaphragm shall be provided on air-cooled engines to isolate the engine power section and all portions of the exhaust system from the engine accessory compartment.

This diaphragm shall comply with the provisions of § 7.486.

§ 7.489 Drainage and ventilation of fire

zones.

(a) Complete drainage of all portions of designated fire zones shall be provided to minimize the hazards resulting from failure or malfunctioning of components containing flammable fluids. The drainage provisions shall be effective under conditions expected to prevail when drainage is needed and shall be so arranged that the discharged fluid will not cause an additional fire hazard.

(b) All designated fire zones shall be ventilated to prevent the accumulation of flammable vapors. Ventilation openings shall not be placed in locations which would permit the entrance of flammable fluids, vapors, or flame from other zones. The ventilation provisions shall be so arranged that the discharged vapors will not cause an additional fire hazard.

(c) Category A: Except with respect to the engine power section of the powerplant compartment, provision shall be made to permit the crew to shut off sources of forced ventilation in any fire zone, unless the amount of extinguishing agent and rate of discharge are based on maximum air flow through the zone. Subpart F-Equipment

§ 7.600 Scope.

GENERAL

The required basic equipment as prescribed in this subpart is the minimum which shall be installed in the rotorcraft for certification. Such additional equipment as is necessary for a specific type of operation is prescribed in the operating rules of the regulations in this subchapter.

§ 7.601 Functional and installational requirements.

Each item of equipment installed in a rotorcraft shall be:

(a) of a type and design appropriate to perform its intended function;

(b) Labeled as to its identification, function, or operational limitations, or any combination of these, whichever is applicable;

(c) Installed in accordance with specified limitations of the equipment; and (d) Demonstrated to function properly in the rotorcraft.

§ 7.602 Required basic equipment.

The equipment listed in §§ 7.603 through 7.605 shall be the required basic equipment. (See § 7.600.)

§ 7.603 Flight and navigational instru

ments.

(See § 7.612 for installation requirements.)

(a) Air-speed indicating system.

(b) Altimeter (sensitive).

(c) Clock (sweep-second).

(d) Free-air temperature indicator.

(e) Gyroscopic bank and pitch indicator (non-tumbling type).

(f) Gyroscopic rate-of-turn indicator (with bank indicator).

(g) Gyroscopic direction indicator. (h) Magnetic direction indicator. (i) Rate-of-climb indicator (vertical speed).

§ 7.604 Powerplant instruments.

(See 7.613 for installation requirements.)

(a) Carburetor air temperature indicator for each engine.

(b) Cylinder head temperature indicator for each air-cooled engine, or coolant temperature indicator for each liquid-cooled engine.

(c) Category A: An individual fuel pressure indicator for each engine and either an independent warning device for each engine or a master warning device for all engines with means for isolating the individual warning circuit from the master warning device.

(d) Category B: An individual fuel pressure indicator for each engine.

(e) Fuel quantity indicator for each fuel tank. (See § 7.437.)

(f) Low fuel warning device for each tank if a multi-tank system is employed. (See § 7.416.)

(g) Manifold pressure indicator for each engine, if altitude engines are used.

(h) Category A: An individual oil pressure indicator for each engine and either an independent warning device for each engine or a master warning device for all engines with means for isolating the individual warning circuit from the master warning device.

(i) Category B: An individual oil pressure indicator for each engine.

(j) Oil pressure warning device for each pressure-lubricated gear box to in

dicate when the oil pressure falls below a safe value.

(k) Oil quantity indicator for each oil tank and each rotor drive gear box, if lubricant is self-contained. (See § 7.613 (d).)

(1) Oil temperature indicator for each engine.

(m) Oil temperature warning device to indicate when the oil temperature in any rotor drive gear box exceeds a safe value.

engine.

(n) Tachometer for each (These tachometers may be combined in a single instrument with that required by paragraph (o) of this section, except that such an instrument shall indicate rotor rpm during autorotation.)

(0) Tachometer(s) to indicate rotor rpm of the main rotor(s), or for each main rotor, the speed of which can vary appreciably with respect to another main rotor.

(p) Category A: Fire warning indicators. (See § 7.485.)

(q) Category B: Fire warning indicators when fire detection is required. (See 7.485.)

§ 7.605

Miscellaneous equipment.

There shall be installed:

(a) Approved seats for all occupants. (See 7.355.)

(b) Approved individual safety belts for all occupants. (See § 7.643.)

(c) Master switch arrangement for electrical circuits other than ignition. (See § 7.622 (c).)

(d) Source(s) of electrical energy. (See § 7.620.)

(e) Electrical protective devices. (See § 7.624.)

(f) Hand fire extinguishers. (See §§ 7.380 (a) and 7.381 (e) and (f).)

(g) Windshield wiper or equivalent for each pilot station. (See § 7.351 (b).) (h) Radio communication system (two-way).

(i) Ignition switch for each and all engines. (See § 7.472.)

§ 7.606 Equipment, systems, and installations.

(a) Functioning and reliability. All equipment, systems, and installations, the functioning of which is necessary in showing compliance with the regulations in this subchapter, shall be designed and installed to insure that they

will perform their intended functions reliably under all reasonably foreseeable operating conditions.

(b) Hazards. All equipment, systems, and installations shall be designed to safeguard against hazards to the rotorcraft in the event of their malfunctioning or failure.

(c) Category A; power supply. Where an installation, the functioning of which is necessary in showing compliance with the regulations in this subchapter, requires a power supply, such installation shall be considered an essential load on the power supply, and the power sources and the system shall be capable of supplying the following power loads in probable operating combinations and for probable durations:

(1) All loads connected to the system with the system functioning normally.

(2) All essential loads after failure of any one prime mover, power converter, or energy storage device.

(3) All essential loads after failure of any one engine on two- or three-engine rotorcraft, or after failure of any two engines on rotorcraft with four or more engines.

(4) In determining the probable operating combinations and durations of essential loads for the partial power failure conditions prescribed in subparagraphs (2) and (3) of this paragraph, it shall be permissible to assume that the power loads are reduced in accordance with a monitoring procedure which is consistent with safety in the types of operations authorized. If a particular load is not required to maintain controlled flight, it need not be considered for the two-engine-inoperative condition on rotorcraft with four or more engines as prescribed in subparagraph (3) of this paragraph.

INSTRUMENTS; INSTALLATION

§ 7.610 General.

The provisions of §§ 7.611 through 7.613 shall apply to the installation of instruments in rotorcraft.

NOTE: It may be necessary to duplicate certain instruments at two or more crew stations to meet the instrument visibility requirements prescribed in § 7.611, or when required by the operating rules of the regulations in this subchapter for reliability or cross check purposes in particular types of operations. In this case independent operating systems are required in accordance with the provisions of § 7.612 (f).

§ 7.611 Arrangement and visibility of instrument installations.

(a) Flight, navigation, and powerplant instruments for use by each pilot shall be plainly visible to him from his station with the minimum practicable deviation from his normal position and line of vision when he is looking out and forward along the flight path.

and

(b) The required instruments consisting of the air-speed indicator, gyroscopic direction indicator, gyroscopic bank and pitch indicator, gyroscopic turn bank indicator, altimeter, rate-of-climb indicator, rotor tachometer(s), and manifold pressure indicator, shall be grouped and shall be centered as nearly as practicable about the vertical plane of the pilot's forward vision. Additional instruments considered of prime importance to the safe operation of the rotorcraft shall be included in the grouping.

(c) All other required powerplant instruments shall be closely grouped on the instrument panel.

(d) Identical powerplant instruments for the several engines shall be located to prevent any misleading impression as to the engines to which they relate.

(e) Powerplant instruments vital to the safe operation of the rotorcraft shall be plainly visible to the appropriate crew members.

(f) The vibration characteristics of the instrument panel shall be such as not to impair seriously the accuracy of the instruments or to damage them.

§ 7.612 Flight and navigational instru

ments.

(a) Air-speed indicating systems(1) Calibration of instruments to indicate true air speed. Air-speed indicating instruments shall be calibrated to indicate true air speed at sea level in the standard atmosphere with a minimum practicable instrument calibration error when the corresponding pitot and static pressures are applied to the instrument.

(2) Relation between IAS and CAS. The air-speed indicating system shall be calibrated to determine the system error; i.e., the relation between IAS and CAS. This calibration shall be determined over an appropriate range of speeds:

(i) In flight for the flight conditions of climb, level flight, and autorotation; and,

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