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 6-1. (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 6-2, where I is the minimum intensity prescribed in Figure 6-1 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 adjacent signals shall not exceed the values given in Figure 6-3, except that higher intensities in the overlaps shall be acceptable with the use of main beam intensities substantially greater than the minima specified in Figures 6-1 and 6-2 if the overlap intensities in relation to the main beam intensities are such as not to affect adversely signal clarity.

FIGURE 6-3-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.

§ 6.634-1 Overlaps between high intensity forward position lights (FAA policies which apply to § 6.634 (b) (3)).

When the peak intensity of the forward position lights is greater than 100 candle, the maximum overlap intensities between them may exceed the values given in Figure 6-3, provided the overlap intensity in Area A is not greater than 10 percent of peak position light intensity and the overlap intensity in Area B is not greater than 2.5 percent of peak position light intensity."

[Supp. 15, 23 F. R. 1001, Feb. 15, 1958]

(a) Aviation red.

"y" is not greater than 0.335, "z" 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.

"r" is not less than 0.350,

"r" is not greater than 0.540,

"y-y" is not numerically greater than 0.01, y being the y coordinate of the Planckian radiator for which 2,=2.

2 Overlap intensities should be determined with the position lights installed in their actual rotorcraft locations, since adjacent rotorcraft structure will often provide some cutoff in the overlap areas.

§ 6.636 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. § 6.637 Anti-collison light system.

An airplane to be eligible for night operation shall have installed an anticollision light system. Such system shall consist of one or more approved anticollision 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 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.

The ar

(b) Flashing characteristics. rangement 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 shall be the frequency at which the rotorcraft's complete anti-collision light system is observed from a distance, and shall apply to all sectors of light including the overlaps which might exist when the system consists of more than one light source. In overlaps, flash frequencies higher than 100 cycles per minute shall be permissible, except that they shall not be higher than 180 cycles per minute.

(c) Color. The color of the anticollision lights shall be aviation red in accordance with § 6.635 (a).

(d) Light intensity. The minimum light intensities in all vertical planes,

FIGURE 6-4-Minimum effective intensities for anticollision lights.

[Amdt. 6-1, 22 F. R. 1275, Mar. 1, 1957]

§ 6.637-1 Anti-collision light standards (FAA policies which apply to § 6.637).

The anti-collision light standards in § 6.637 apply to rotorcraft for which an application for a type certificate is made on or after April 1, 1957. When anticollision lights are installed on rotorcraft for which an application for a type certificate was made before April 1, 1957, the applicant may conform either to § 6.637 or the standards listed below:

(a) Anti-collision lights (when installed) should be of the rotating beacon type installed on top of the fuselage in such a location that the light will not be detrimental to the crew's vision and will not detract from the conspicuity of the position lights. If there is no acceptable location on top of the fuselage, a bottom fuselage installation may be used.

(b) The color of the anti-collision light should be aviation red in accordance with the specifications of § 6.635.

(c) The arrangement of the anti-collision light, i. e., number of light sources, beam width, speed of rotation, etc., should be such as to give an effective flash frequency of not less than 40 and

§ 6.643 Safety belts.

Rotorcraft manufactured on or after the effective date of this part (January 15, 1951) shall be equipped with safety belts of an approved type. See § 6.18.) In no case shall the rated strength of the safety belt be less than that corresponding with the ultimate load factors specified, taking due account of the dimensional characteristics of the safety belt installation for the specific seat or berth arrangement. Safety belts shall be attached so that no part of the anchorage will fail at a load lower than that corresponding with the ultimate load factors specified. (See § 6.260.)

$6.644 Emergency flotation and signaling equipment.

hen emergency flotation and signalquipment is required by the operatrules of the regulations in this subapter such equipment shall comply with the provisions of paragraphs (a) through (c) of this section.

(a) Rafts and life preservers shall be of an approved type and shall be so in

stalled as to be readily available to the crew and passengers.

(b) Rafts released automatically or released by the pilot shall be attached to the rotorcraft by means of lines to keep them alongside the rotorcraft. The strength of the lines shall be such that they will break before submerging the empty raft.

(c) Signaling devices shall be free from hazard in their operation and shall be installed in an accessible location.

MISCELLANEOUS EQUIPMENT

§ 6.650 Hydraulic systems.

(a) Design. Hydraulic systems and elements shall withstand, without exceeding the yield point, all structural loads which are expected to be imposed in addition to the hydraulic loads.

(b) Tests. Hydraulic systems shall be substantiated by proof pressure tests. When proof tested, no part of a hydraulic system shall fail, malfunction, or experience a permanent set. The proof load of any system shall be 1.5 times the maximum operating pressure of that system.

(c) Accumulators. Hydraulic accumulators or pressurized reservoirs shall not be installed on the engine side of the fire wall, except when they form an integral part of the engine.

Subpart G-Operating Limitations and Information

(a) The operating limitations in §§ 6.710 through 6.718 shall be established as prescribed in this part.

(b) The operating limitations, together with any other information concerning the rotorcraft found necessary for safety during operation, shall be included in the Rotorcraft Flight Manual (§ 6.740), shall be expressed as markings and placards (§ 6.730), and shall be made available by such other means as will convey the information to the crew members.

OPERATING LIMITATIONS

§ 6.710 Air-speed limitations; general.

When air-speed limitations are a function of weight, weight distribution, altitude, rotor speed, power, or other factors, the values corresponding with all critical combinations of these values shall be established.

(1) 0.9V established in accordance with § 6.204, or

(2) 0.9 times the maximum speed demonstrated in accordance with § 6.140.

(b) It shall be permissible to vary the never-exceed speed with altitude and rotor rpm, provided that the ranges of these variables are sufficiently large to allow an operationally practical and safe variation of the never-exceed speeds. § 6.712 Operating speed range.

An operating speed range shall be established for each rotorcraft. § 6.713 Rotor speed.

Rotor rpm limitations shall be established as set forth in paragraphs (a) and (b) of this section. (See also § 6.710.)

(a) Maximum power off (autorotation). Not to exceed 95 percent of the maximum design rpm determined under § 6.204 (b) or 95 percent of the maximum rpm demonstrated during the type tests (see 6.103 (b)), whichever is less.

(b) Minimum-(1) Power off. Not less than 105 percent of the higher of the following:

(i) The minimum demonstrated during the type test (see § 6.103 (b)), or

(ii) The minimum determined by design substantiation.

(2) Power on. Not less than the higher of the following:

(i) The minimum demonstrated during the type tests (see § 6.103 (a)), or

(ii) The minimum determined by design substantiation and not higher than a value determined in compliance with § 6.103 (a).

§ 6.714 Powerplant limitations.

The powerplant limitations set forth in paragraphs (a) through (c) of this section shall be established for the rotorcraft. They shall not exceed the corresponding limits established as a part of the type certification of the engine installed on the rotorcraft.

(a) Take-off operation. The take-off operation shall be limited by:

(1) The maximum rotational speed, which shall not be greater than the max

imum value determined by the rotor design, nor greater than the maximum value demonstrated during type tests.

(2) The maximum permissible manifold pressure.

(3) The time limit upon the use of the corresponding power.

(4) The maximum allowable cylinder head, coolant outlet, or oil temperatures, if applicable when the time limit of subparagraph (3) of this paragraph exceeds two minutes.

(b) Continuous operation. The continuous operation shall be limited by:

(1) The maximum rotational speed, which shall not be greater than the maximum value determined by the rotor design, nor greater than the maximum value demonstrated during type tests.

(2) The minimum rotational speed demonstrated in compliance with the rotor speed requirements as prescribed in § 6.713 (b) (2). (See §§ 6.103, 6.710, and 6.711.)

(c) Fuel octane rating. The minimum octane rating of fuel required for satisfactory operation of the powerplant within the limitations prescribed in paragraphs (a) and (b) of this section. § 6.716 Rotorcraft weight and center of gravity limitations.

The rotorcraft weight and center of gravity limitations to be established are those required to be determined by §§ 6.101 and 6.102.

§ 6.717 Minimum flight crew.

The minimum flight crew shall be established by the Administrator as that number of persons which he finds necessary for safety in the operations authorized under § 6.718. This finding shall be based upon the workload imposed upon individual crew members with due consideration given to the accessibility and the ease of operation of all necessary controls by the appropriate crew members.

§ 6.718 Types of operation.

The type of operation to which a rotorcraft is limited shall be established on the basis of flight characteristics and the equipment installed. (See the operating parts of this subchapter.)

§ 6.719 Maintenance manual.

The applicant shall furnish with each rotorcraft a maintenance manual to contain information which he considers

(a) The markings and placards specified in §§ 6.731 through 6.738 are required for all rotorcraft.

(b) Markings and placards shall be displayed in conspicuous places and shall be such that they cannot be easily erased, disfigured, or obscured.

(c) Additional information, placards, and instrument markings having a direct and important bearing on safe operation of the rotorcraft shall be required when unusual design, operating, or handling characteristics so warrant. § 6.731

Instrument markings; general.

(a) When markings are placed on the cover glass of the instrument, provision shall be made to maintain the correct alignment of the glass cover with the face of the dial.

(b) All arcs and lines shall be of sufficient width and so located that they are clearly visible to the pilot.

§ 6.732 Air-speed indicator.

Instrument indications shall be in terms of indicated air speed. The markings set forth in paragraphs (a) through (c) of this section shall be used to indicate to the pilot the maximum and minimum permissible speeds and the normal precautionary operating ranges. (See §§ 6.116, 6.612(a), 6.710, 6.711, 6.712, and 6.713.)

(a) A red radial line shall be used to indicate the limit beyond which operation is dangerous.

(b) A yellow arc shall be used to indicate the precautionary operating range.

(c) A green arc shall be used to indicate the safe operating range.

[21 F.R. 10291, Dec. 22, 1956, as amended by Amdt. 6-4, 24 F.R. 7074, Sept. 1, 1959] § 6.733 Magnetic direction indicator.

A placard shall be installed on or in close proximity to the magnetic direction indicator which shall comply with the requirements of paragraphs (a)

through (c) of this section. (See § 6.612 (c).)

(a) The placard shall contain the calibration of the instrument in a level flight attitude with engine(s) operating.

(b) The placard shall state whether the calibration was made with radio receiver(s) on or off.

(c) The calibration readings shall be in terms of magnetic headings in not greater than 45° increments.

§ 6.734 Powerplant instruments; general.

All required powerplant instruments shall be marked in accordance with paragraphs (a) through (c) of this section. (See § 6.613.)

(a) The maximum and the minimum (if applicable) safe operation limits shall be marked with red radial lines.

(b) The normal operating ranges shall be marked with a green arc not extending beyond the maximum and minimum safe operational limits.

(c) The take-off and precautionary ranges shall be marked with a yellow arc. § 6.735 Oil quantity indicator.

Oil quantity indicators shall be marked in sufficient increments to indicate readily and accurately the quantity of oil. (See § 6.613(d).)

§ 6.736 Fuel quantity indicator.

When the unusable fuel supply for any tank exceeds 1 gallon or 5 percent of the tank capacity, whichever is greater, a red arc shall be marked on the indicator extending from the calibrated zero reading to the lowest reading obtainable in the level flight attitude. (See §§ 6.421 and 6.613 (b).) A notation in the Rotorcraft Flight Manual shall be made to indicate that the fuel remaining in the tank when the quantity indicator reaches zero is not usable in flight. (See § 6.741 (f).)

[21 F.R. 10291, Dec. 22, 1956, as amended by Amdt. 6-4, 24 FR. 7074, Sept. 1, 1959]