INSTRUCTIONS FOR SUPER HUEY TABLE OF CONTENTS OVERVIEW 1 LOADING THE PROGRAM IN AMIGA 2 LOADING THE PROGRAM IN ATARI (NOT TYPED IN THESE INSTS) 3 HELICOPTER CONTROL CONVENTIONS 4 UH-1XA FLIGHT CONTROL 7 INSTRUMENTS 11 COMPUTER CONTROL FUNCTIONS 15 WEAPONS FIRE 15 COMPUTER COMMANDS 16 TAKE-OFF, FLIGHT AND LANDING 17 AUTOROTATIVE LANDING 19 MISSION ASSIGNMENTS 20 THE MISSIONS 20 NAVIGATION 24 OVERVIEW The UH-1XA is a new, experimental high performance helicopter using the latest in electronic control systems and stabilization. Its features include: *State-of-the-art electronic instrument console *On-board computer that regulates and monitors ship's systems and provides pilot messages and commands for special operations. *Automatic pitch control to engine power linkage for RPM equilibrium, including synchronization of anti-torque pitch (with manual override). The UH-1XA is powered by a new VLW (very light weight) piston engine molded from a super-strength, superlight composite metal of militarily classified process, which rivals the weight to thrust ratio of most turbo shaft engines, and provides lower echelon field maintenance capabilities. Mounted vertically, the engine is coupled to the main rotor shaft through a custom direct drive transmission that auto clutches to a 10 to 1 engine to rotor RPM reduction rate. The rotor assembly consists of semi-rigid blades and a hub articulation system that is adjusted servo-electronically to respond to flight conditions. This system causes flight drag reduction of 40 to 60% with resultant improvement in speed, performance and fuel economy. Structually based on Bell Helicopters' UH-1 series, the UH-1XA's fuselage is molded in carbon fiber laminates for optimum aero-dynamic characteristics and low weight. Defensively, the fuselage is vulnerable to weapons fire, although the unique elasticity of the material resists and deflects hits better than metal exteriors of equivalent weight. The streamlined cockpit seat one pilot in front with room for a navigator/ pilot directly behind. Space amidship allows three additional personnel to squeeze in. The main controls are incorporated into one unique incremental controller -- a revolutionary and controversial innovation that replaces the collective, cyclic and anti-torque controls of conventional helicopters. While the UH-1XA's innovative controller requires new techniques to be learned by both novices and experienced pilots, it also provides advantages. In solo flight, it allows the pilot to fly the craft while also operating the on board computer, radio and weapons. The weapons system includes rockets that can be armed in sets of four and fired at one second intervals. Two machine guns, mounted one on each side of the fuselage, fire in tandem. Maximum load is 20 rockets and 2,000 machine gun rounds. The UH-1XA was not specifically designed as a military aircraft. It's high speed and long range is useful for reconnaissance or rescue, while its armaments provide adequate defense capability. The UH-XA represents a new direction in helicopter flight and control system design. See your Huey dealer and fly one when it becomes available. In the meantime, prepare yourself with the Super Huey Flight Simulator from Cosmi! LOADING THE PROGRAM INTO THE AMIGA SYSTEM REQUIREMENTS FOR THE AMIGA 1000 1) The Super Huey Disk 2) Amiga Computer with 512K minimum RAM 3) The Amiga Mouse Note: The mouse should be plugged into port #2 during play, leave the disk in the drive. 1) Be sure your computer, monitor, computer keyboard and mouse are correctly connected. 2) Install the Kickstart (version 1.1 or later), and power on the computer. Also power on the monitor. If your system is already initialized, just warm boot to reset. 3) Place the Super Huey disk in the computer's built-in drive. 4) When the 1> symbol appears, type in the letters SH and press the return key on the computer keyboard. 5) After the title sequence plays, you are in the cockpit of the Super Huey UH-1XA. 6) To choose your mission, press the F7 key to power up the on board computer, they type in the word mission, press the return key followed by one of the four mission commands: 1) SCHOOL 2) EXPLORE 3) COMBAT 4) RESCUE LOADING THE PROGRAM INTO THE ATARI ST (These instructions were not included by the typist). HELICOPTER CONTROL CONVENTIONS This is not intended as a tutorial on helicopter but rather a general description of the traditional and well understood characteristics of rotary-wing aircraft. The physics of flight are the same for fixed wing and rotary wing aircraft, but the helicopter introduces some complex problems over airplanes. In the first place, airplanes are inherently stable whereas helicopters are inherently unstable. As a result, planes tend to maintain straight and level flight, while helicopters tend to deviate from it. Both the wing of an airplane and the rotor blade of a helicopter are "airfoils" and interact with the air the same way through the "Bernoulli Effect". Briefly, this describes the effect of the curvature of a wing causing a higher air pressure area below the wing and a low pressure area above, producing (vertical) lift as the wing moves through the air. A fixed wing craft requires forward movement through the air to produce lift. A helicopter blade achieves lift by spinning on a stationary axis, causing the blade to cut through the air, this producing lift (or vertical thrust) in a direction parallel to the axis of rotation of the blade. The amount of lift depends on the "angle of attack" of the airfoil, which is the angle of the blade to vertical. A "flat" blade will produce lift merely because of the airfoil effect, but not enough to lift the mass of the helicopter. The angle of attack is the pitch of the rotor blade -- the pitch is controlled by the pilot -- greater pitch increasing the Bernoulli effect, therefore producing more lift. But, simultaneously, as pitch increases, so does drag, because more power is required to maintain the rotor RPM. The relationship between pitch and RPM is perhaps the most important consideration in operating a helicopter. Another factor in a rotary wing system is the torque reaction of the spinning rotor on the fuselage. The torque of the turning rotor exerts an equal and opposite force on the body of the craft causing it to turn in the direction opposite to the rotation of the blades. Unless counteracted by another force, in this case the action of the tail, (or anti-torque), rotor blade. The tail rotor provides thrust in a direction opposite the torque reaction, thereby equalizing the force and stabilizing the rotation of the craft. Further, the thrust of the tail rotor is controllable by the pilot providing directional control, described as right or left yaw. This is possible because overcompensation of the torque effect will turn the fuselage in the direction of the spinning blades: a thrust less than the force of torque will allow the fuselage to turn opposite the rotor direction. To fly, four main control systems are found in conventional helicopters. These are the cyclic stick, the collective pitch control, the throttle, and the anti-torque (or rudder) pedals. This collective pitch control, usually just called the collective, increases or decreases the pitch of all blades equally, and is the primary vertical thrust control. Normally, pulling up on the collective stick will produce lift and lowering it will decrease lift. As mentioned above, as pitch increases, so does rotor drag, requiring an increase in engine power to maintain RPM. In many helicopters, this synchronization is provided automatically by the link between the collective and the throttle. The throttle controls engine power and RPM directly. It is located on the collective stick to aid in the coordination of pitch and RPM. The anti- torque pedals control the pitch of the tail rotor blades, providing torque compensation and directional control. Normally these are conventional rudder pedals. Finally, the cyclic stick is the main direction control, and determines the attitude of the rotor system. Basically, when the plane of the spinning rotor is horizontal, all the trust produced is directed upwards, perpendicular to the rotor plane and the horizontal axis of the helicopter, and parallel to the rotor shaft axis. Moving the cyclic stick in any direction away from center (the neutral position) tilts the plane of blade rotation -- the rotor -- in the same direction, thereby adding a horizontal component to the thrust caused by the spinning of the blades, causing the helicopter to move in that same direction. For example, moving the cyclic forward will cause forward thrust to a degree which is proportional to the amount of rotor tilt from the horizontal. At the same time the attitude of the fuselage will change to the same degree (in forward flight, a nose down condition). Also, a cyclic change changes the "blade angle of attack" set by the collective pitch control, which will affect RPM and thereby torque reaction. This illustrates an essential characteristic of helicopter controls. Any change in one of the controls will, in most cases, require some adjustment of the others. This fundamental instability in flight behavior is why helicopters must be flown at all times. Summing up, the four main control systems are: *The cyclic controls the direction and attitude of the helicopter. *The collective controls the amount of thrust produced by the rotor blades in the direction set by the cyclic. *The throttle directly controls engine power output and RPM. *The anti-torque control adjusts torque compensation and directional control (by yawing) to maintain heading. UH-1XA FLIGHT CONTROL The Super Huey Control System is divided into two main components: the computer keyboard and the incremental flight controller. The keyboard design is based on the familiar computer, with full key complement and 10 function control keys. The UH-1XA functions are: FUNCTION KEY COMPUTER ON F7 START ENGINE F8 ENGAGE ROTOR CLUTCH F9 CUT POWER F10 The remainder of the keyboard and other functions are used to enter commands and data to the on board computer, and control the Super Huey UH-1XA's weapons system. The flight control device is a UH-1XA innovation, and houses all four of the helicopter's normal control devices into a single unit. The "mouse" style controller may be positioned to the pilot's satisfaction, and it accommodates itself to each pilot's own style of operation. It operates on an uncluttered flat surface, and employs two activation switches: a left button operated switch and a right button operated switch. The UH-1XA Control operates in two modes: the cyclic mode, wherein the controller operates like a normal helicopter's cyclic control stick, and collective mode, wherein the controller effects the throttle and rotor blade pitch angles. Pressing the left button engages the cyclic control; pressing the right button engages the collective. Starting with the controller at any position on the surface comfortable to the pilot. A button is pressed and held down, and the control is moved slightly forward (away from the pilot), backwards (toward the pilot), or to either side to engage a specific operation. The operation is engaged until the button is released, or the controller is moved in another direction. Please note that the top line on the on board computer screen verifies the operation currently engaged, and that the current position of the controller is always relative to the its last position. With both buttons released, the controlled may be moved to any comfortable starting position for the next incremental control move. Movement of the controller will be described with compass directions: Forward-North, Back-South, Left-West, Right-East, with Northwest or Southwest movement of the cyclic producing left yaw and Northeast or Southeast movement of the cyclic producing right yaw. With the exception of hard bank turns, all other cyclic and collective controls changes are designed to "set to hold". This control will be continuous until an opposite control maneuver to the same degree is executed by the pilot. For example, pushing the control to the Northwest will lessen tail rotor thrust, allowing the fuselage to begin turning to the left. The longer the control is held in that direction, the greater the reaction in tail rotor thrust. Returning the control to center will not eliminate this change, and the helicopter will continue turning left. To stop turning, the pilot must increase tail rotor thrust by moving the control to the Northwest. This counteracting thrust, correctly applied will stop the turning and the helicopter will fly a straight course. This counteracting thrust, applied too vigorously, will cause the helicopter to turn right, for which left correcting yaw control must be applied. Similarly, in the collective mode, an increase in lift produced by moving the control South will build vertical thrust. This lift attitude will remain the same until the collective is lowered (moved northward), thereby reducing lift. If the resultant lift is not enough to overcome with weight of the helicopter, then it will begin to descend, and, if conducted at a proper rate, land safely. Only experience will allow the pilot to discover the precise points of equilibrium for successful maneuvers. INSTRUMENTS 1) FRE-Automatic VHF omnidirectional range transmission from a local station or base used by the navigation computer to set a heading to the transmission heading. 2) HOM-A homing device with an effective range of approximately 25 miles may be dropped using the HOM command. The heading to the drop spot from the helicopter is transmitted from the HOMing device is displayed here. 3) NAV-Compass navigation heading computed from the VOR transmission. (1) The AUTO (Automatic Course Correction) command may be used to copy this heading to the automatic course (COR) setting (2) or the NAV heading may be followed manually. 4) RES-This is the heading displayed by a homing transmitter in the possession of the ground personnel to be located. This readout will activate automatically when within range of the REScue signal. 5) NAV SCREEN-Blip marks location of current active NAVigation, or REScue transmission source relative to the position of the helicopter within an 8-mile radius. 6) ARM-ARM is when the machine guns are activated during the COMBAT mission. 7) 1 2 3 4-These numerals represent rocket bays one, two, three and four. When the rockets are loaded into the bays, the numerals are lit. When the rockets are armed, the indicator lights are on. 8) INDICATOR LIGHTS-Routine automatic systems check will light the appropriate indicator if a malfunction is found in the electronic systems. Cycling lights indicate check in progress: non-cycling light on indicates malfunction. 9) ON BOARD COMPUTER-On board computer screen displays cyclic and collective action, computer messages, and the pilot's computer keyboard commands. 10-11) ENG-Engine tachometer set includes digital readout of engine revolutions per minute (RPM) and a sliding needle gauge. Red areas on needle gauge indicate low or excessive levels. Yellow areas are cautionary levels. Pale blue area is the normal operating range. 12) MFLD-The manifold pressure gauge indicates engine power output. Red area indicates dangerously high pressure. Note: The engine automatically cuts off to prevent rupture at high manifold pressure levels. 13-14) ROT-Rotor tachometer set includes digital readout of rotor RPM and sliding needle gauge. Red, yellow and pale blue areas are explained above under ENG. 15) FUL-Fuel gauge 16) OIL-Oil pressure gauge. Optimum reading is center mark. 17) TMP-Engine temperature gauge. Normal reading is center mark. 18) WIN-Ambient wind direction. 19) PCH-Collective pitch gauge: shows degree of blade pitch between from "full low" (zero degree angle of attack) to the highest pitch point. 20) HORIZON-Artificial horizon indicates the fuselage attitude relative to a horizon line. 21) COM-Compass heading. 22) COR-Automatic course setting indicates preset heading (set with the AUTO on board computer command), which will be followed if there is no manual flying control. Note: Although many stabilization features are included in the UH-1XA, the inherent instability of helicopters makes automatic course setting with the AUTO command only 70 to 80% reliable. 23) ATQ-Anti-torque gauge indicates level of rotor torque compensation by the tail rotor. Also indicates rate of yaw. 24) AMP-Ampmeter gauge indicates electrical power output. Normal reading is center mark. 25) EXH-Exhaust/cylinder head temperature gauge indicates engine operating conditions. Optimum reading is center mark. 26) SPD-Indicates wind speed in the direction indicated by the WINd gauge. 27) CRB-Carburetor gauge: during warm-up, this gauge shows "full-rich" fuel mixture for primary ignition, which then falls to medium. At normal operating temperatures, the gauge indicates carburetor intake air temperature. 28-29) SPEEDOMETER-The speedometer set includes digital readout and sliding needle gauge. Red, yellow, and pale blue areas are explained above under ENG. 30) GROUND PROXIMITY GAUGE-Vertical needle gauge shows elevation from 0 to 200 feet. 31-32) ALTIMETER-The Altimeter set includes digital readout and sliding needle gauge. Red, yellow and pale blue areas are explained above under ENG. 33) MALFUNCTION LIGHTS-Indicator lights illuminate in the event of malfunction or excessive readings in its related instrument. COMPUTER CONTROL FUNCTIONS F1, F2, F3 and F4 - Loads rockets bays number 1 through 4 respectively on first press, arms rockets 1 through 4 respectively on second press. F5 - In combat mission, arms the UH-1XA's machine guns F6 - Not used F7 - Powers on board computer F8 - Starts the engine. The engine will not start until the on board computer command POW is entered. F9 - Engage rotor clutch. It is not advisable to engage rotor clutch until engine RPM exceeds 1200 RPM. F10 - Cut engine power. This stops the engine. The rotor clutch automatically disengages and the rotor "free-wheels" to an autorotative landing. WEAPONS FIRE Left Amiga (Red A by space bar) - Rockets are fired using left A. Right Amiga (Read A by space bar) - Fires machine guns. COMPUTER COMMANDS Enter at least the first three letters of the computer command. Make corrections with the on board computer's delete (DEL) key. When the command is complete, press the on board computer's RETURN key. ABORT - Abort current mission and stop all activity. AUTO - Set automatic course correction. When prompted by SET, enter compass heading. Auto works only when there is no manual control input. CLIMATE - Displays current climatic conditions including temperature, humidity, and barometric reading. DISTANCE - Displays line-of-sight distance from take-off point. HOMING - Drop a homing device that transmits directional signal to the navigation computer. MISSION - Select new mission, then enter one of the following commands into the on board computer: (1) SCHOOL - Flight Instruction (2) EXPLORE - Exploration and mapping (3) COMBAT - Air battle (4) RESCUE - Personnel rescue mission. Note: The mission can be changed anytime, which aborts the mission currently in progress. POWER - Turn on power SEND - Send coordinates when landing or during emergency. VOR - Activate VHF Range reception for navigation. VSI - Display digital vertical speed reading XXX - Cancel previous command input. (Not available on immediate action commands). STANDARD TAKE-OFF, FLIGHT AND LANDING PROCEDURES 1) Turn on the computer with the F7 key, then enter MIS to select an assignment. Select your mission when prompted by the on board computer. 2) Enter the POW command to turn on power. 3) Start the engine (F8). Wait for engine temperature gauges to warm up to middle range, then increase throttle to bring engine RPM to about 1200 RPM. 4) Engage rotor clutch (F10). Wait for RPM to stabilize at approximately one-tenth of the engine RPM. Monitor oil pressure and carburetor gauges for normal operating levels. Observe instruments for engine malfunctions and high or low temperature levels. 5) Increase throttle to build RPM to take off speed (3500-3600 engine, 350-360 rotor RPM). Note: Make sure that collective pitch is at FULL LOW before increasing throttle. 6) With engine at proper RPM begin to increase pitch with the control (collective south). As lift is attained, watch for wind drift and instability. Control position and heading with rudder (yaw) control (cyclic NW, NE, SW, SE). Continue to control pitch angle as necessary to obtain smooth vertical movement. Equalize lift to attain a stationary hover at 90-100 feet. 7) Select heading with the rudder control and begin moving the control, in cyclic mode, forward (cyclic north). As some airspeed is achieved, add more lift with the collective to go into a climbing forward attitude. While forward cyclic increases RPM, back collective maintains RPM due to a throttle link. It is very important to hold RPM at a constant rate during cyclic/collective adjustments. Also forward cyclic will tilt the fuselage forward bringing the nose down. Hold the ship at the proper attitude with back cyclic adjustments. Increase forward thrust and airspeed with the collective control rather than the cyclic control to maintain flight attitude, but monitor the degree of pitch and manifold pressure to stay at safe levels. Holding the control too long in any position will result in over controlling. Make adjustments small and gradual to achieve a smooth steady, controlled rate of change. 8) Bring airspeed to between 70 and 90 knots and continue climbing to at least 500 feet, which is the minimum altitude from which an autorotative landing can be made in the event of engine failure. 9) Once desired altitude is reached, decrease collective to a point of lift equilibrium allowing straight and level flight. Watch the airspeed indicator and altimeter for steady and consistent readings. 10) During straight and level flight, maintain altitude and airspeed with both cyclic and collective control, and hold steady course with rudder (yaw)) control. Watch the magnetic compass for your heading. 11) To return to base, bank a full 180 degree turn to right or left (cyclic left or right). Monitor your heading on the compass. Slightly BEFORE reaching the desired return heading, bring the control to center and level off. 12) While flying forward and in close proximity to the base, begin descent by gradually decreasing pitch (collective south). As altitude decreases, maintain airspeed with cyclic control. Keep the descent rate constant with pitch adjustments on the collective. Watch your ground proximity gauge for the needle to approach center, which is an altitude of 100 feet, then slowly increase collective pitch to reduce descent speed. Also, decrease forward thrust by applying "back" cyclic (cyclic south) to "flare" the helicopter, which brings the nose up and further reduces the speed of descent. At 20 to 25 feet, bring the ship to zero airspeed and hover, then gradually decrease lift with the collective to lower the helicopter to the ground. Just before touchdown, add some degree of lift to cushion your landing. Once on the ground, immediately DECREASE PITCH TO FULL LOW. 13) Cut the engine and power with the F10 key. The rotor clutch will disengage and gradually slow to stop. The engine cannot be started again until the rotor has come to a complete stop. AUTOROTATIVE LANDING Autorotative is a maneuver wherein, through failure or intent, the engine has stopped and the rotor is spinning freely. Control during autorotative is similar to powered flight, with the exception that rotor RPM is maintained by either free-wheeling rotating blade is then an airfoil as in an autogyro, the forerunner to helicopter. Therefore, speed or sufficient elevation to permit accumulation of speed is necessary for an autorotative landing. To control autorotative descent, try to gain a high forward glide speed, while reducing drag by reducing collective pitch, yet keeping enough lift to check the rate of descent. Near the ground, a full flare maneuver with back cyclic (cyclic south) combined with a quick and substantial collective pitch increase (collective south) should cut vertical speed enough to allow a fairly soft touchdown. Note: Your local library will have information on the flight characteristics of helicopters, and with the exception of their standard control configuration, will be of further help learning to operate UH-1XA with confidence and skill. MISSION ASSIGNMENTS 1) FLIGHT INSTRUCTION (Enter SCHOOL) - Computer controlled flight training. The computer will lead you through a series of maneuvers from take-off to landing with simple control pull control of the on board computer. However, the trainee is in full control of the aircraft and should have an understand- ing of the instruments and controls before attempting the flight. 2) EXPLORATION AND MAPPING (Enter EXPLORE) - Fly a survey mission over previously uncharted territory. Map out the general terrain, major geological features, water supply, timberland or sings of habitation. 3) RESCUE (Enter RESCUE) - Military personnel are either lost or incapacitated. The mission is to locate, transmit heading and distance, and, if possible, land and pick up the party. The helicopter's maximum passenger capacity on this mission is four. 4) AIR BATTLE (Enter COMBAT) - A secret desert installation to which you are assigned is under possible threat of attack by unknown hostile forces. You job is reconnaissance and, if necessary, defense. Determine enemy's strength and determine if engagement is feasible. All mission assignments are unrestricted in form and within the general outline of the mission are nonrepetitive. All command decisions are the responsibility of the pilot. Refueling and repairs are at the take off point only. In the event of crash landings, damage, or emergency set downs, the current mission is terminated. THE MISSIONS FLIGHT INSTRUCTION This training mission tests your ability to follow flying procedures in an efficient and competent manner. The on board computer is programmed to lead you through a flight that employs the maneuvers necessary to develop flying skill and familiarize you with the terms associated with flight procedures. In the mission, observe the on board computer screen for your instructions, then obey them in a responsive, controlled manner. Flying skill is evidenced by a gentle, firm hand on the controls, and smooth transmission from one maneuver to another. When your mission is over, only you will know how you performed -- you are on the honor system. The training flight can be taken at any time. EXPLORATION AND MAPPING The essential task of this mission is to map the terrain that surrounds your base. Mapping can be a very long and involved process, and is probably best done in stages to prevent the inaccuracies from careless work caused by fatigue. The are to be explored is quite large, and is evidenced by ground objects such as forests, low hills, towns, lakes and other unique terrain features. Note that vegetation, water, and other features cause pronounced variations in color of the terrain. Monotonous terrain without changing ground characteristics indicates that you have flown beyond the exploration area. Establish your pattern of sweep early, and as you monitor your headings, pay close attention to ground features. Note their location from your position and distance from the base, and any other triangulation method you develop. As an example of a type of pattern you might like to establish, let's assume that you have chosen to start in the quadrant Northwest of the base. Take off from the base and fly North Northwest. Check your distance from the base with the DISTANCE computer command, and when you are approximately five miles out, then turn due west to a compass heading of 270. Your NAV gauge should be showing a heading of approximately 150 from your position back to the base. As you continue west, the NAV will move toward a reading of 090. Continue due west for the distance necessary to cover the area you have chosen. When you reach that distance, turn due north (COM 000), travel 10 miles and turn due east (COM 090). Maintain that course, continuing to observe and note ground features, until the NAV reading approaches 180, which means the base is due south of you. Go north 10 miles again, then turn due west, again noting ground features, maintaining course and calculating the point at which you turn to backtrack for the next leg of your search. Planning and practice will determine that searching pattern that produce best results. RESCUE Military personnel are stranded. They are transmitting from a homing device whose heading will register on your REScue digital display once you are within range of it. But, since your briefing only indicates that the general location of the party is unknown, careful ground-covering search and rescue techniques must be employed. At an elevation that permits visual detection of the ground party, select a compass quadrant and establish a search pattern that allows for the transmission range of their device -- from five to 10 miles. Once the heading is received and followed, keep your eyes open. Military sorties into the desolate country are required to carry signal flares. Once the flare has been sighted, visual reckoning should bring you to a position over the party -- and they should be overjoyed to see you. A careful landing will provide the grateful party the opportunity to climb aboard, and insure your ability to deliver them safely to the base. AIR BATTLE At desert base of undetermined location you will do battle with an unidentified enemy helicopter force. Their position is in relatively close proximity to your base, and they change their field of operation often, and so no heading from the base is safe. When they discover you, it is all out combat, and the skies won't be friendly until you have eliminated them all. Your base is not a safe haven, because they will pursue you to their last man. It takes skillful flying to evade their deadly attacks. Your defense weapons are rockets and machine guns. They are fixed mount and aimed straight ahead. While machine gun fire must be extremely accurate, the rockets have proximity detonators that arm in flight, and so can destroy the enemy without a direct hit. The machine guns short fire-to-target time permits quick response once Super Huey is head onto target. To be successful with the rockets, you must anticipate the enemies flight path. You have 20 rockets, which must be loaded into the rocket bays, then armed, before being fired in 1 2 3 4 sequence. 32 enemy craft must be vanquished, so judicious use of the rockets and the 2,000 machine gun rounds available to you to insure victory. Fortunately, the enemy apparently has a kamikaze code, and will approach and fire only from your front. Evasive action, combined with aggressive use of your arsenal and flying skills, is your only chance. Not recommended, but perhaps useful for greater accuracy, the field sight developed by Huey Cobra pilots in Viet Nam may be useful to you, but perhaps harmful to your equipment. In Nam, pilots with a grease pencil, drew an "X" on their windshield to mark the point of convergence of their weapons fire. NAVIGATION To understand the NAV and RES readouts of compass headings for navigation it is necessary to adopt the proper perspective relationship of the earth and helicopter. The headings displayed are coordinates relative to the magnetic compass, but the computer always sees itself at the exact center of the compass with the earth moving beneath it. Assume that a compass diagram showing North, East, South and West is affixed to the aircraft. Whenever you fly, the vertical line that always points East and West always converge at the helicopter. All other locations are measured from this helicopter centered intersection. Let us take off from Base, the source of the VOR transmission, with our NAV active and fly due north. The COMpass reading will be 000. If we observe the NAV readout we see that it reads 180, the opposite of our flight heading because that base is now directly behind us to the South. If we stop, hover and turn completely around until the COM reads 180 and fly straight ahead and south, the NAV also reads 180 until we pass over the base, at which point the NAV will change to 000, or due north, since the base is now behind us as we continue on our southward heading of 180. In the same manner, had we flown due East from Base at a COMpass reading of 90, the NAV readout would indicate 270, a west heading, since it is showing the heading necessary for return to the base. Before flying in some other direction, a further understanding of the way headings are computed is necessary. Since there is only one signal coming from one direction on which to home in on, the position of the source cannot be triangulated, and therefore the NAV heading is not absolutely accurate and becomes significantly inaccurate beyond a range of 25 miles. To compute the helicopter's position from base transmitter, a single source, the computer first uses a north/south bias that selects either north or south numbers depending on the incoming signal. A discrete measurement is made of the angle of reception to find the distance to the east or west of the source. To see how this works out, let us take off from BASE and this time fly Northeast at COMpass reading of 040. What happens to the NAV readout? As we move in a somewhat northward direction, we know the base is somewhat south so the NAV reading will be some southern degree. Similarly, since we are also flying eastward, the Base is somewhat to the west of our position. Therefore, the NAV heading to the base from the helicopter falls somewhere between South (180) and west (270). Therefore, as we remain in the quadrant Northeast of the base, the NAV heading should vary between 180 and 270. What would happen if we turned due North (COMpass heading 000)? At that moment, the NAV readout would not change since we are at the same relative position to be base. If, on the other hand, we turned southeast the NAV would to move toward 270 as we continued in a southwest direction. But, when we cross the line due east from the base (where the NAV reads 270) and enter the quadrant southeast of the base, the NAV readout would 'flips' to a Northwest heading. The inaccuracy of the NAV heading is approximately 10% beyond 25 miles of the base, and increases proportionally with distance. Therefore, flying southeasterly and crossing the line due east from the base as in the example above, at a great distance a NAV heading of 230 could 'flip' to as much as 330. Since the base is now Northwest of the helicopter, the NAV reading is incorrect but indicates the correct quadrant. In practice, the pilot should interpret the NAV heading with consideration to the inaccuracies of the system. If one followed the NAV heading exactly as the numbers indicated, the course travelled back to Base would be an arc rather than a straight line as the readings grow more accurate within 25 miles of the base. A thorough understanding of the error introduced into the NAV headings and the bias in the error toward the previous locations of the craft will allow the pilot to 'cut in' on the arc and fly a more direct course by leading the NAV heading in the direction of change. For example, you are somewhere northwest of Base: the NAV reads 150. If you travel east, the number changes to 160, 165, 170, etc. As you can see, the heading is moving toward due south (180). If you originally did not follow the heading 150 but, instead, turned more southerly, say 160, you would actually be moving more directly toward the Base. Calculating the amount of lead is a matter of geometry and practice but, as you see, the selection in this instance must be a considered estimate between 150 and 180. If you choose the lesser. THE END