Sky-High Adventure with the Macintosh, Amiga, & Atari ST
by Charles Gulick
Active runway: (Often shortened to “the active”) The runway in use, based primarily on wind conditions and occasionally on traffic conditions. When more than one runway is in use, smaller aircraft are typically required to use the shortest runway.
AGL: Above Ground Level. Used to describe an aircraft's altitude above the ground. Aircraft instruments do not provide the pilot with this information. Altitude AGL must be deduced from the altimeter, charts, and knowledge of the terrain over which the aircraft is operating.
Ailerons: Pilot-controllable surfaces on the rear or trailing edge of each wing used to roll the aircraft and thus turn it. Acting in opposite directions, they increase lift on one wing while decreasing it on the other, causing the aircraft to roll on its longitudinal axis and to bank and turn in the direction of the lower wing.
Airfoil: A structural shape, such as the shape of an aircraft's wings and tail surfaces, that creates or contributes to lift.
Airspeed Indicator: A panel instrument that notifies the pilot of the aircraft's rate of speed through the air. It operates by measuring the pressure of the relative wind against the wings. Indicated airspeed in the Cessna 182 is not true airspeed nor is it the same as groundspeed. (See their definitions in this glossary.) In the Gates Learjet, the indication is of true airspeed (TAS).
Altimeter: A panel instrument that tells the pilot the aircraft's altitude above sea level, also referred to as MSL (mean sea level) altitude. The altimeter works by measuring decreases or increases in atmospheric pressure as the aircraft climbs or descends.
Angle of attack: The angle between the relative wind and the chord line of a wing or other airfoil. The chord line is an imaginary line through the center of an airfoil, drawn from the leading to the trailing edge.
Artificial Horizon: A panel instrument depicting an aircraft's attitude with respect to the earth's horizon. It continuously updates and displays a symbol of the horizon and of the aircraft's wings and nose in relation to that horizon.
ATC: Air Traffic Control. A ground-based radio network at many (but not all) airports, consisting of: Ground Control, which provides taxiing instructions; Tower, which provides instructions and clearances (permission) for takeoffs and landings; Departure Control and Approach Control for the airspace immediately surrounding the airport; and Center, which controls the airspace at higher altitudes. Flight Simulator procedures cover only the Tower portion of the network and only to a minor degree.
ATIS: Automatic Terminal Information Service. A radio aid that provides weather and other information about a given airport, including the designation of the active runway.
Atmospheric pressure: The pressure exerted on the earth by its atmosphere. Also termed “barometric pressure” because it is measured by a barometric device.
Auto-coordination: A system by which the ailerons and rudder of an aircraft are interconnected so that control of one provides coordinated control of the other, eliminating skidding or slipping in turns.
Bank: The lateral tilting of an aircraft—the result of rolling it about its longitudinal axis—that causes it to turn in the direction of the lower wing. The roll is begun by application of aileron in the desired direction of bank and turn.
Bleed off: To decrease a value, such as airspeed or altitude, in a slow and controlled manner.
Ceiling: The altitude at which the bottom boundary of the lowest cloud layer in an overcast will be encountered.
COM: Short for communications. In Flight Simulator, the communications radio.
Control yoke: See Yoke.
Crabbing: A condition of flight in which, due to the direction of winds aloft, the aircraft is moving somewhat sideways through the air but following a straight line in relation to the ground. Named after the manner in which crabs move.
Density altitude: Pressure altitude (as shown on an altimeter) referenced to temperature for computing aircraft performance.
Directional gyro: See Heading indicator.
DME: Distance Measuring Equipment. Provides the pilot with a panel readout of the aircraft's distance from a VOR station in nautical miles.
Drag: Forces that oppose an aircraft's movement through the air and that act parallel to and in the same direction as the relative wind.
Elevators: Pilot-controllable surfaces on the trailing edge of the horizontal stabilizer, used to pitch the aircraft's nose up or down or keep it level with the horizon, thus controlling airspeed. Elevators are controlled by the yoke. Pulling back on the yoke moves the elevators up, and the relative wind forces the tail downward while the nose pitches up. Releasing back pressure or applying forward pressure on the yoke produces the opposite result.
FAA: Federal Aviation Administration.
Flaps: Pilot-controllable airfoils on the trailing edge of the wings, used to assist the pilot in takeoffs, slowflight, and landings. On takeoff, lowering or extending the flaps by 10 degrees (nominal) provides the highest lift-to-drag ratio and shortens the distance required to get airborne. Lowered flaps assist in slowflight by increasing drag and at the same time reducing the aircraft's stalling speed. On landing approaches, flaps are lowered—frequently all the way—to accommodate a steeper angle of descent, for instance for clearing obstacles or flying tight airport patterns. Flaps also permit touchdown at a lower airspeed, due to a higher coefficient of lift and thus a lower stalling airspeed. After touchdown, the drag of the flaps shortens the landing roll.
Flare: The leveling-off phase of a landing approach, prior to touchdown, that brings the aircraft level or slightly nose-high. It is performed a foot or so above the runway in actual aircraft but somewhat higher than that in the simulator to compensate for the relative insensitivity and slow reaction time of the simulated control.
FPM: Feet Per Minute. Used to measure an aircraft's rate of climb or descent.
Gear: See Landing gear.
Glideslope: A navigation aid used on ILS landing approaches, consisting of a horizontal needle that displays the correct vertical position for the aircraft in its approach to the runway threshold. The pilot keeps the needle centered by continuously monitoring the angle of descent and adjusting it as required. The glideslope is used in conjunction with the Localizer.
Groundspeed: An aircraft's actual speed over the ground, which is not available as an instrument readout but must be calculated.
Heading: The magnetic compass direction in which the aircraft is pointed in relation to a 360-degree circle. It is not necessarily the direction the aircraft is traveling. (See, for instance, Crabbing.)
Heading indicator: (Also called directional gyro.) A compass controlled by a gyroscope. It gives to the pilot heading information based on forces that act on the gyro, rather than on magnetic readings. It obviates the lag inherent in magnetic compasses and requires no settling time, as does a magnetic compass, after turns and climbs.
Horizontal stabilizer: The fixed horizontal surface at the rear of the aircraft, equipped with controllable elevators. See also Elevators.
IAS: Indicated Air Speed. See KIAS.
IFR: Instrument Flight Rules. The rules by which aircraft must be flown when in instrument conditions, or when flight by visual reference is difficult or impossible. (Compare VFR.)
ILS: Instrument Landing System. A system of radio aids that displays on the instrument panel three-dimensional references by which a pilot can make a landing approach without outside visual references. It consists of a localizer, glideslope, marker beacons, and approach lights. (Approach lights are not included in Flight Simulator.)
KIAS: Knots Indicated Air Speed. An aircraft's airspeed in knots as read on the airspeed indicator.
Knots: Nautical miles per hour, abbreviated kn. A knot equals 1.1507 statute miles, or, conversely, a statute mile equals .869 knots. The simulator airspeed indicator and the DME read in knots (although the DME is not consistent).
Landing gear: The appendage of struts and wheels on which the airplane lands. Both the simulated Cessna 182 and Gates Learjet have tricycle gear, which comprises a nose-wheel and two main wheels, that enables the aircraft to sit level on the ground. Landings should, however, be made on the main wheels, with the nosewheel lowered to the runway only after the plane has landed and slowed down.
Localizer: A radio navigational aid used in conjunction with the glideslope on ILS landing approaches. The localizer needle is a vertical needle that displays the correct horizontal position for the aircraft on its approach to the runway threshold. The pilot keeps the needle centered by continuously monitoring the heading and adjusting it as required.
Magneto: A device that creates the high voltages required for aircraft engine spark plugs. It combines the functions of an automobile engine's coil and distributor.
Marker Beacons: Labeled O, M, and I on the instrument panel. Outer, Middle, and Inner marker beacons consist of visible and audible signals that tell the pilot the relative distance from the end of the runway on ILS approaches.
OBI: Omni-Bearing Indicator. A panel instrument that gives the pilot information about the aircraft's position relative to the VOR station to which the NAV radio is tuned. It consists of an OBS, or Omni-Bearing Selector, for selecting a course or radial; a TO-FROM indicator, advising whether the aircraft is flying toward or away from the station; a CDI, or course deviation indicator (or “needle” for short) that the pilot keeps centered; and in the case of NAV 1, glideslope and localizer (or glidepath) needles that indicate, respectively, the correct vertical and horizontal courses to the runway threshold on an ILS approach.
OMNI: Short for Omni-Bearing Indicator and/or its components; also, loosely, a VOR station.
Phonetic alphabet: The terms used to transmit letters and numbers via aircraft radio to prevent misunderstandings:
Note that numbers are spoken as individual digits. For example, 297 is spoken as “too niner seven.”
Pitch: The angle between the longitudinal axis of the aircraft and the horizon. Pitch is described as “nose up,” “nose down,” or “level.” Pilots also say an aircraft is “pitched up” or “pitched down.”
Power setting: The amount of throttle, or fuel flow, applied to the engine, determined in an actual aircraft by the position of the throttle (a push-pull control) and in the simulated aircraft by the number of notches of throttle applied.
Rate of climb: The rate at which the airplane climbs, measured in feet per minute. Also used, illogically, to define the rate at which the airplane is descending (although “rate of descent” is better applied to that condition). However, the term “zero rate of climb” can be used without confusion.
Rate of climb indicator: See VSI.
Rate of turn: The rate at which the aircraft turns, measured in degrees per second, as a result of its airspeed and the sideways force, or horizontal lift component, that is causing it to turn. The rate of turn at any given airspeed is controlled by the angle of bank.
Rotation: The act of rotating the aircraft on takeoff, that is, the use of back pressure to raise the nose prior to takeoff. The aircraft is rotated as it reaches climb speed.
RPM: Revolutions Per Minute. The measure of the speed at which the aircraft's engine and, in the Cessna 182, the propeller fastened to its crankshaft are turning as a result of the amount of throttle applied, the aircraft's pitch, and other flight conditions.
Rudder: Pilot-controllable surface on the trailing edge of the vertical stabilizer that controls yaw, or rotation about the aircraft's vertical axis.
Skid: A sliding of the aircraft to the left or right out of alignment with the desired flight path. A skidding turn results when centrifugal force is greater than horizontal lift, pulling the aircraft toward the outside of the turn.
Slip: A yawing of the aircraft toward the outside of the path of a turn. A slipping turn results when horizontal lift is greater than centrifugal force.
Stack: (Also called “radio stack.”) The section of the instrument panel that contains the COM, NAV, and transponder radios, usually in a stack.
Tachometer: The instrument that measures the speed of rotation of the engine, in revolutions per minute (rpm). Often abbreviated “tach.”
TAS: True Air Speed. Airspeed after compensation for density altitude. The Gates Learjet airspeed indicator reads TAS.
Taxi: To move an aircraft on the ground.
Throttle: The control that determines the speed of rotation of the engine's crankshaft in revolutions per minute (or in the Learjet, the percentage of available power applied to the engines) by the rate at which it permits fuel to flow.
Trim: Small control surfaces that affect the elevators, making it unnecessary to maintain pressures on the yoke. Also, to set those surfaces by using a trimming device in the cockpit. In this book, for more precise control trim is simulated by elevator settings because no pressures can be felt by the simulator pilot.
Vertical stabilizer: (Also called the “fin.”) A fixed vertical surface at the rear of the aircraft to which a movable surface—the rudder—is hinged. The vertical stabilizer helps to stabilize the aircraft in the vertical or yaw axis.
VFR: Visual Flight Rules. Rules that govern flights in visual conditions, or when visual references are adequate for safe control of an aircraft. Compare IFR.
VOR: Very high frequency Omnidirectional Range. A radio transmission system that enables pilots who have the necessary equipment to navigate precisely along or over magnetic course radials (all of which converge at specific VOR stations).
VOR station: The facility that houses a VOR transmission system and equipment. Each VOR station has a name, which is usually that of an airport or nearby town.
VSI: Vertical Speed Indicator. A panel instrument that shows the aircraft's rate of ascent or descent in feet per minute (fpm).
Yaw: An aircraft's rotation about its vertical axis. The vertical axis is also called the yaw axis.
Yoke: The pilot's control column, similar in appearance (but not performance) to an automobile steering wheel. The yoke incorporates aileron and elevator control, resulting from “pressures” applied by the pilot. The term “pressure” stresses the fact that the yoke is not pushed, pulled, or turned abruptly or forcefully but is moved slowly and in small increments. Pressure to the left or the right operates the ailerons. Backward or forward pressure operates the elevators. The yoke returns to its neutral position when pressure is released.