Lights: Angular limits.
Section 11
SEC. 11. Lights: Angular limits.—The angular limits laid down in these rules will be determined as when the aircraft is in normal flying position. Airplane lights.—Between sunset and sunrise airplanes in flight must show the following lights— On the right side, a green light so constructed and fixed as to show an unbroken light between two vertical planes whose dihedral angle is one hundred and ten degrees when measured to the right from dead ahead, and visible at a distance of at least two miles. On the left side, a red light so constructed and fixed as to show an unbroken light between two vertical planes whose dihedral angle is one hundred and ten degrees when measured to the left from dead ahead, and visible at a distance of at least two miles. At the rear and as far aft as possible, a white light shining rearward, visible in a dihedral angle of one hundred and forty degrees bisected by a vertical plane through the line of flight and visible at least three miles. Licensed aircraft, when engaged in carrying passengers for hire any time between sunset and sunrise, shall be equipped with electric landing lights and parachute type of flares, or approved equivalent, in addition to the navigation lights required. Airship lights.—Between sunset and sunrise airships shall carry and display the same lights that are prescribed for airplanes, excepting the side lights which shall be doubled horizontally in a fore-and-aft position and the rear light shall be doubled vertically. Lights in a pair shall be at least seven feet apart. Balloon lights.—A free balloon, between sunset and sunrise, shall display one white light not less than twenty feet below the car, visible for at least two miles. A fixed balloon, or airship, shall carry three lights—red, white, and green—in a vertical line, one over the other, visible at least two miles. The top red light shall be not less than twenty feet below the car, and the lights shall be not less than seven nor more than ten feet apart. Lights when stationary.—(1) Between sunset and sunrise all aircraft which are on the surface of the water and not under control, or which are moored or anchored in navigation lanes, shall show a white light visible for at least two miles in all directions. (2) Balloon and airship mooring cables between sunset and sunrise shall show groups of three red lights at intervals of at least every ten feet, measured from the basket, the first light in the first group to be approximately twenty feet from the lower red balloon light. The object to which the balloon is moored on the ground shall have a similar group of lights to mark its position.