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A-7D NAVIGATION AND WEAPON DELIVERY SYSTEM
The A-7D navigation and weapon delivery system frees the pilot during
an attack run from a compulsory straight path approach to the target (precalculated
dive angle, airspeed, altitude and pipper-on-target), which
considerably reduces vulnerability to enemy fire. The system permits a
highly flexible attack envelope, augmenting the pilot's ability to
find targets, maneuver when necessary, and reattack promptly when
required.
This flexibility is made possible primarily through the projected
displays-the head-up display (HUD), the forward looking radar, the
projected map-and the digital computer.
The digital computer is the indispensable central element, integrating
the displays, sensors, controls and pilot's commands. Its most
important role is to solve ballistic prediction problems in real time,
which permits a free selection of flight path and altitude during the
weapons pass. During navigation, it continually derives and displays
present position and destination guidance data. Using a control panel
in the cockpit, the pilot can 'converse' with the computer, prestoring
up to nine destinations which can be called up during flight. Also,
while flying to destination the pilot may see and 'mark' nine
additional locations or possible targets, entering them into the
computer for subsequent return to the locations or for readout of
their coordinates after landing.
The HUD, driven by the computer, provides a continuous representation
of steering, velocity and extrapolated target location, A flight path
marker indicates where the airplane is going. During weapons delivery,
an azimuth steering line depicts the path along which the bomb impact
will move in time. An aiming reticle represents the computed target
location. When in range, solution cues move down the azimuth steering
line and upon intersection with the aiming reticle, a computed release
occurs automatically.
The computer also drives the projected map display which provides a
continuous display of aircraft geographical position. A range
indicator shows distance from present position to the selected
destination. By correlating outstanding geographic features on the map
with the adjacent radarscope, the pilot can easily interpret ground
mapping radar returns, and can instantly check his position even under
instrument conditions or at night. |
