AN 01-25CN-2             PARAGRAPH 1
 b. GUN CAMERA.

   (1) GENERAL.-A government-furnished G.S. A.P. type N-2 gun camera is mounted in the leading edge of the right landing gear fairing. (See Fig. 115.)

   (2) GUN CAMERA REMOVAL.-To remove the camera, unbutton the Dzus fasteners in the leading edge of the landing gear fairing. Squeeze together the two projecting knobs on the swinging mount and tilt the camera forward. This procedure will give access to the electrical conduit plug, which can be removed by unscrewing from the camera. Remove the camera by removing the four bolts attaching the mounting plate to the camera. This method of removal will not change the adjustment of the camera.

   (3) ADJUSTMENT.-The adjustment of the gun camera can be made only at the time of sighting the guns at a target. To adjust the camera, insert the optical camera aligner in place of the film magazine. Loosen the two screws which tighten the collar assembly to the adapter ball and adjust the camera to bring the target into the reticle of the optical aligner. Tighten the two screws and check the image of the target in the aligner.

   (4) LUBRICATION.

     (a) GUN CAMERA-A thin film of grease, grade 375, Spec. 3560, should be applied to the gear teeth. A drop of oil, Spec. 3562, should be applied to the pivots and bearings. Remove all excess oil to prevent its spread to the lens or film.

 c. GUNNERY EQUIPMENT.

   (1) GENERAL. - The gunnery equipment con. sists of a modified N-3B gun sight and six .50 caliber wing guns with 1410 rounds of .50 caliber ammunition as normal load and 1696 rounds as overload.

   (2) GUN SIGHT.

     (a) GENERAL-The gun sight, type N-3B, is supported by a casting-mounted on the forward armor plate at Sta. 2A. The sight is above the instrument panel on the centerline of the airplane. It may be removed without disturbing the setting by removing the nut attaching the yoke assembly to the base assembly.

          (b) SIGHT ADJUSTMENT.-The sight assembly may be adjusted in a rotational, horizontal, or vertical direction. Rotational adjustment may be accomplished by means of two adjustment bolts on the top side of the connection between the yoke assembly and base assembly, forward of the instrument panel. One bolt and three screws, 90" apart, beneath the sight assembly, regulate the horizontal and vertical adjustment. The top bolt and bottom screw control the vertical adjustment, and the right and left screws the horizontal adjustment.

   (c) RETICLE ADJUSTMENT.-The reticle may be adjusted by means of a knob on the right side of the sight by loosening the set screw and turning the knob. When the proper reticle adjustment is attained, be sure to lock the adjusting knob with the set screw. Ile sight should be so adjusted that the reticle image, when viewed as reflected on the mirror and superimposed on a target approximately 500 yards distant, does not change in relation to the target as the head is moved over the field of vision.

 (3) GUN INSTALLATION.-The gun installation (Drawing 87-69-803) consists of three .50 caliber model M-2 aircraft machine guns mounted in each wing panel. The guns fire clear of the propeller disc.

 This contractor is installing four (4) guns in the airplane and sending the remaining two guns and all parts needed for installation, as loose equipment.

 (4) AMMUNITION BOXES-The ammunition installation consists of two single and two double ammunition boxes in each wing panel. The normal ca. pacity is 235 rounds per gun.' The two leading outboard compartments serve the center gun. The two trailing outboard compartments serve the inboard gun and the two inboard boxes serve the- outboard gun. The ammunition boxes are accessible through doors on the top surface of the wing. The feed chute to the center gun must be removed before the two inboard ammuni. tion boxes can be removed. Instructions for loading the boxes are on instruction plates mounted on the box tops.

 (5) CHUTES.-All ejection chutes are made of stainless steel. Empty cases are guided from the bottom of the gun through the wing by a case chute under each gun. ne links are ejected from the side of the gun and are guided to and through the bottom of the wing by link chutes.