(ii) In ground effect during the accelerated take-off run.

(3) Category A and Category B; multiengine rotorcraft. The air-speed error of the installation, including the airspeed indicator instrument calibration error, shall not exceed 3 percent or 5 mph, whichever is greater:

(i) Throughout the speed range in level flight at forward speeds of 10 mph or over, and

(ii) Through the speed range in climb of 10 mph below the take-off climb-out safety speed (see § 7.114 (a)) to 10 mph above the best rate-of-climb speed.

(4) Catagory B; single-engine rotorcraft. Calibration of the air-speed indicator shall be made in flight at all forward speeds of 10 mph or over. The air-speed error of the installation, including the air-speed indicator instrument calibration error, shall not exceed 3 percent or 5 mph, whichever is greater, at any forward speed above 80 percent of the climb-out speed.

(5) Arrangement of system. The airspeed indicating system shall be arranged insofar as practicable to preclude malfunctioning or serious error due to the entry of moisture, dirt, or other substances.

(6) Heated pitot tube. The air-speed indicating system shall be provided with a heated pitot tube or equivalent means of preventing malfunctioning due to icing.

(b) Static air vent and pressure altimeter systems. (1) All instruments provided with static air case connections shall be vented to the outside atmosphere through an appropriate piping system.

(2) The vent(s) shall be so located on the rotorcraft that its orifices will be least affected by air flow variation, moisture, or other foreign matter.

(3) The installation shall be such that the system will be airtight, except for the vent into the atmosphere.

(4) Pressure altimeters shall be of an approved type and shall be calibrated to indicate pressure altitude in standard atmosphere with a minimum practicable instrument calibration error when the corresponding static pressures are applied to the instrument.

(5) The design and installation of the altimeter system shall be such that the error in indicated pressure altitude at sea level in standard atmosphere, ex

cluding instrument calibration error, does not result in a reading more than 30 feet high nor more than 30 feet low in the level flight speed range 0 mph to 0.9 Vн.

(c) Magnetic direction indicator. (1) The magnetic direction indicator shall be installed so that its accuracy will not be excessively affected by the rotorcraft's vibration or magnetic fields of a permanent or transient nature.

(2) After the magnetic direction indicator has been compensated, the calibration shall be such that the deviation in level flight does not exceed ±10° on any heading.

(3) A calibration placard shall be provided as specified in § 7.733.

(d) Automatic pilot system. If an automatic pilot system is installed, it shall be of an approved type, and the following shall be applicable:

(1) The system shall be so designed that the automatic pilot can either:

(i) Be quickly and positively disengaged by the human pilots to prevent it from interfering with their control of the rotorcraft, or

(ii) Be sufficiently overpowered by one human pilot to enable him to control the rotorcraft.

(2) A means shall be provided to indicate readily to the pilot the alignment of the actuating device in relation to the control system which it operates, except when automatic synchronization is provided.

(3) The manually operated control(s) for the system's operation shall be readily accessible to the pilots.

(4) The automatic pilot system shall be of such design and so adjusted that, within the range of adjustment available to the human pilot, it cannot produce hazardous loads on the rotorcraft or create hazardous deviations in the flight path under any conditions of flight appropriate to its use either during normal operation or in the event of malfunctioning, assuming that corrective action is initiated within a reasonable period of time.

(e) Category A; instruments utilizing a power supply. Each required flight instrument utilizing a power supply shall be provided with two independent sources of power, a means of selecting either power source, and a means of indicating the adequacy of the power being

supplied to the instrument. The installation and power supply system shall be such that failure of any flight instrument connected to one source, or of the energy supply from one source, or a fault in any part of the power distribution system, will not interfere with the proper supply of energy from the other source. (See also §§ 7.606, 7.620, and 7.654.)

(f) Duplicate instrument systems. If duplicate flight instruments are required by the operating regulations in this subchapter (see note under § 7.610), the operating system for a duplicate instrument shall be completely independent of the operating system for the duplicated instrument. Additional instruments shall not be connected to the first pilot system. If additional instruments are connected to the other system, provision shall be made to disconnect or isolate in flight such additional instruments. [21 F.R. 3744, June 2, 1956, as amended by Amdt. 7-4, 24 F.R. 7076, Sept. 1, 1959]

§ 7.613 Powerplant instruments.

(a) Instrument lines. (1) Powerplant instrument lines carrying flammable fluids or gases under pressure shall be provided with restricted orifices or equivalent safety devices at the source of the pressure to prevent the escape of excessive fluid or gas in case of line failure.

(2) The provisions of §§ 7.432 and 7.433 shall be made applicable to powerplant instrument lines.

Means

(b) Fuel quantity indicator. shall be provided to indicate to the flight crew the quantity in gallons or equivalent units of usable fuel in each tank during flight. The following shall apply:

(1) Tanks, the outlets and air spaces of which are interconnected, shall be considered as one tank for the purpose of providing separate indicators.

(2) Exposed sight gauges shall be protected against damage.

(3) Fuel quantity indicators shall be calibrated to read zero during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply as defined by § 7.416. (See § 7.736.)

(c) Fuel flowmeter system. When a flowmeter system is installed, the metering component shall include a means for by-passing the fuel supply in the event that malfunctioning of the metering

The provisions of §§ 7.621 through 7.626 shall apply to all electrical systems and equipment (see also § 7.606).

§ 7.621 Electrical system capacity.

The required generating capacity and the number and type of power sources shall be determined by an electrical load analysis and shall comply with § 7.606. § 7.622 Generating system.

(a) The generating system shall be considered to include electrical power sources, main power busses, transmission cables, and associated control, regulation, and protective devices.

(b) The generating system shall be so designed that the power sources function properly both when connected in combination and independently, and the failure or malfunctioning of any power source cannot create a hazard or impair the ability of the remaining sources to supply essential loads.

(c) Means accessible in flight to appropriate crew members shall be provided for the individual and collective disconnection of electrical power sources from the main bus.

(d) Means shall be provided to indicate to appropriate crew members those generating system quantities which are essential for the safe operation of the system.

NOTE: The voltage and current supplied by each generator are quantities considered essential.

§ 7.623 Distribution system.

(a) The distribution system shall be considered to include all distribution busses, their associated feeders, and control and protective devices.

(b) Category A: Individual distribution systems shall be designed to insure that essential load circuits can be supplied in the event of reasonably probable faults or open circuits.

(c) Where two independent sources of electrical power for particular equipment or systems are required by the regula

tions in this subchapter, their electrical energy supply shall be assured.

NOTE: Various means may be used to assure a supply, such as duplicate electrical equipment, throw-over switching, and multichannel or loop circuits separately routed.

§ 7.624 Electrical protection.

(a) Automatic protective devices shall be provided to minimize distress to the electrical system and hazard to the rotorcraft in the event of wiring faults or serious malfunctioning of the system or connected equipment.

(b) Category A: In the generating system, means shall be provided to automatically de-energize and disconnect from the main bus any power source which develops hazardous overvoltage.

(c) All resettable type circuit protective devices shall be so designed that, when an overload or circuit fault exists, they will open the circuit irrespective of the position of the operating control.

(d) Protective devices or their controls used in essential load circuits shall be accessible for resetting in flight.

(e) Circuits for essential loads shall have individual circuit protection.

NOTE: This provision does not necessarily require individual protection for each circuit in an essential load system; e. g., each position light in the system.

(f) If fuses are used, there shall be provided spare fuses for use in flight equal to at least 50 percent of the number of fuses of each rating required for complete circuit protection.

§ 7.625 Electrical equipment and installation.

(a) In showing compliance with § 7.606 (a) and (b) with respect to the electrical system, equipment, and installation, consideration shall be given to critical environmental conditions.

NOTE: Critical environmental conditions may include temperature, pressure, humidity, ventilation, position, acceleration, vibration, and presence of detrimental substances.

(b) All electrical equipment, controls, and wiring shall be so installed that operation of any one unit or system of units will not affect adversely the simultaneous operation of any other electrical unit or system of units essential to the safe operation of the rotorcraft.

(c) Cables shall be grouped, routed, and spaced so that damage to essential circuits will be minimized in the event of faults in heavy current-carrying cables.

(d) Storage batteries shall be of such design and so installed that:

(1) Safe cell temperatures and pressures are maintained during any probable charging or discharging condition. No uncontrolled increase in cell temperature shall result when the storage battery is recharged (after previous complete discharge) at maximum regulated voltage, during a flight of maximum duration, under the most adverse cooling condition likely to occur in service. Tests to demonstrate compliance with this regulation shall not be required if satisfactory operating experience with similar batteries and installations has shown that maintaining safe cell temperatures and pressures presents no problem.

(2) Explosive or toxic gases emitted by the storage battery in normal operation, or as the result of any probable malfunction in the charging system or the battery installation, shall not accumulate in hazardous quantities within the rotorcraft.

(3) Corrosive fluids or gases which may be emitted or spilled from the storage battery shall not damage surrounding rotorcraft structure or adjacent essential equipment.

[21 F.R. 3744, June 2, 1956, as amended by Amdt. 7-4, 24 F.R. 7076, Sept. 1, 1959]

§ 7.626 Electrical system fire and smoke protection.

The design and installation of all components of the electrical system shall comply with the pertinent fire and smoke protection provisions of §§ 7.358 (c) and 7.385. All electrical cables, terminals, and equipment which are necessary in emergency procedures and which are located in designated fire zones shall be fire-resistant.

(b) Landing lights shall be installed so that there is no objectionable glare visible to the pilot and so that the pilot is not adversely affected by halation.

(c) Landing lights shall be installed in a location where they provide the necessary illumination for night operation including hovering and landing.

(d) A switch for each light shall be provided, except that where multiple lights are installed at one location a single switch for the multiple lights shall be acceptable.

§ 7.632 Position light system installation.

(a) General. In addition to this section, the provisions of §§ 7.633 through 7.635 shall be applicable to the position light system as a whole. The position light system shall include the items specified in paragraphs (b) through (d) of this section.

(b) Forward position lights. Forward position lights shall consist of a red and a green light spaced laterally as far apart as practicable and installed forward on the rotorcraft in such a location that, with the rotorcraft in normal flying position, the red light is displayed on the left side and the green light is displayed on the right side. The individual lights shall be of an approved type.

(c) Rear position light. The rear position light shall consist of a white light mounted on the rotorcraft as far aft as practicable. The light shall be of an approved type.

(f) Light covers and color filters. Light covers or color filters used shall be of flame-resistant material and shall be constructed so that they will not change color or shape or suffer any appreciable loss of light transmission during normal

use.

[21 F.R. 3744, June 2, 1956, as amended by Amdt. 7-1, 22 F.R. 1276, Mar. 1, 1957] § 7.633

Position light system dihedral

angles.

The forward and rear position lights as installed on the rotorcraft shall show unbroken light within dihedral angles specified in paragraphs (a) through (c) of this section.

(a) Dihedral angle L (left) shall be considered formed by two intersecting vertical planes, one parallel to the longitudinal axis of the rotorcraft and the other at 110° to the left of the first,

when looking forward along the longitudinal axis.

(b) Dihedral angle R (right) shall be considered formed by two intersecting vertical planes, one parallel to the longitudinal axis of the rotorcraft and the other at 110° to the right of the first, when looking forward along the longitudinal axis.

(c) Dihedral angle A (aft) shall be considered formed by two intersecting vertical planes making angles of 70° to the right and 70° to the left, respectively, looking aft along the longitudinal axis, to a vertical plane passing through the longitudinal axis.

§ 7.634 Position light distribution and intensities.

(a) General. The intensities prescribed in this section are those to be provided by new equipment with all light covers and color filters in place. Intensities shall be determined with the light source operating at a steady value equal to the average luminous output of the light source at the normal operating voltage of the rotorcraft. The light distribution and intensities of position lights shall comply with the provisions of paragraphs (b) and (c) of this section.

(b) Forward and rear position lights. The light distribution and intensities of forward and rear position lights shall be expressed in terms of minimum intensities in the horizontal plane, minimum intensities in any vertical plane, and maximum intensities in overlapping beams within dihedral angles L, R, and A, and shall comply with the provisions of subparagraphs (1) through (3) of this paragraph.

(1) Intensities in horizontal plane. The intensities in the horizontal plane shall not be less than the values given in Figure 7-1. (The horizontal plane is the plane containing the longitudinal axis of the rotorcraft and is perpendicular to the plane of symmetry of the rotorcraft.)

(2) Intensities above and below horizontal. The intensities in any vertical plane shall not be less than the appropriate value given in Figure 7-2, where I is the minimum intensity prescribed in Figure 7-1 for the corresponding angles in the horizontal plane. (Vertical planes are planes perpendicular to the horizontal plane.)

(3) Overlaps between adjacent signals. The intensities in overlaps between

FIGURE 7-3-MAXIMUM INTENSITIES IN OVERLAPPING BEAMS OF FORWARD AND REAR POSITION LIGHTS

NOTE: Area A includes all directions in the adjacent dihedral angle which pass through the light source and which intersect the common boundary plane at more than 10 degrees but less than 20 degrees. Area B includes all directions in the adjacent dihedral angle which pass through the light source and which intersect the common boundary plane at more than 20 degrees. [21 F.R. 3744, June 2, 1956, as amended by Amdt. 7-1, 22 F.R. 1276, Mar. 1, 1957] § 7.635 Color specifications.

The colors of the position lights shall have the International Commission on

Illumination chromaticity coordinates as set forth in paragraphs (a) through (c) of this section.

(a) Aviation red.

"y" is not greater than 0.335,
"2" is not greater than 0.002;
(b) Aviation green.

"r" is not greater than 0.440-0.320y,
"r" is not greater than "y"-0.170,
"y" is not less than 0.390-0.170x;
(c) Aviation white.

"" is not less than 0.350,

"r" is not greater than 0.540,

"y"-"yo" is not numerically greater than

0.01,

"yo" being the "y" coordinate of the Planckian radiator for which xo=x.

§ 7.636 Riding light.

(a) When a riding (anchor) light is required for a rotorcraft operated from water, it shall be capable of showing a white light for at least 2 miles at night under clear atmospheric conditions.

(b) Riding lights shall be installed so that they will show a maximum practicable unbroken light when the rotorcraft is moored or drifting on the water. Externally hung lights shall be permitted.

§ 7.637

Anti-collision light system.

An anti-collison light system shall be installed which shall consist of one or more approved anti-collision lights so located that the emitted light will not be detrimental to the crew's vision and will not detract from the conspicuity of the position lights. The system shall comply with the provisions of paragraphs (a) through (d) of this section. (a) Field of coverage. The system shall consist of such lights as will afford coverage of all vital areas around the rotorcraft with due consideration to the physical configuration and the flight characteristics of the rotorcraft. In any case, the field of coverage shall extend in all directions within 30° above and 30° below the horizontal plane of the rotorcraft, except that a solid angle or angles of obstructed visibility totaling not more than 0.03 steradians shall be permissible.

(b) Flashing characteristics. The arrangement of the system, i. e., number of light sources, beam width, speed of rotation, etc., shall be such as to give an effective flash frequency of not less than 40 and not more than 100 cycles per minute. The effective flash frequency