A.P. 4503D-P.N.
							 Pilots's Notes

				PART V
		       ARMAMENT EQUIPMENT

        88. A-4 sight

       (i)  The A-4 sight (17) above the instrument panel auto-
	    matically computes deflection as a gun, bomb or rocket
	    sight.  The sight image consists of a centre dot inside a
	    circle of diamond-shaped dots.  The sight can be used as
	    a gunsight from sea level to 50,000 ft. and as a bomb-
	    sight from sea level to 10,000 ft.  Range data is supplied
	    to the sight, for gunnery operations by a manual range
	    control or automatically by the AN/APG-30 radar
	    ranging unit.  The radar system also provides automatic
	    search within its range.  It automatically locks onto, and
	    tracks, a target in range and indicates to the pilot when
	    the equipment is tracking the target.  On overland targets
	    below 6,000 ft. radar ranging distance may be reduced
	    by use of the radar range sweep control to prevent the
	    radar from locking on the ground when the target is at
	    lower altitudes.  Bombs can be released automatically
	    at the proper release point by mechanism within the
	    the equipment is tracking the target.  On overland targets
	    below 6,000 ft. radar ranging distance may be reduced
	    by use of the radar range sweep control to prevent the
	    radar from locking on the ground when the target is at
	    lower altitudes.  Bombs can be released automatically
	    at the proper release point by mechanism within the
	    sight.  Electrical power is supplied to the sight through
	    the single-phase inverter.  Manual sight ranging may be
	    used if the A.C. power supply fails or when the radar
	    system does not function properly.  The sight can be
            operated as a fixed graticule sight as long as D.C. power
	    is available.
       (ii) Gun safety switch
	    Electric power for operating the sight, cine camera,
	    radar and guns is controlled by the three-position
	    guarded gun safety switch (118) on the armament panel
	    below the instrument panel.  Power is supplied to the
	    sight, camera and radar when the switch is in either the
	    GUNS or the SIGHT/CAMERA/RADAR position.
	    The gun-firing circuit receives power only when the
	    switch is at GUNS.  When the guard is down, the switch
	    is OFF.

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