Glossary

Pressure demand oxygen system. A demand oxygen system R that supplies 100 percent oxygen at sufficient pressure above Rabbit, the. High-intensity flasher system installed at many the altitude where normal breathing is adequate. Also referred large airports. The flashers consist of a series of brilliant to as a pressure breathing system. blue-white bursts of light flashing in sequence along the approach lights, giving the effect of a ball of light traveling Prevailing visibility. The greatest horizontal visibility toward the runway. equaled or exceeded throughout at least half the horizon circle (which is not necessarily continuous). Radar. A system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and Preventive maintenance. Simple or minor preservative fixed objects such as aircraft, weather formations, and terrain. operations and the replacement of small standard parts The term RADAR was coined in 1941 as an acronym for not involving complex assembly operation as listed in 14 Radio Detection and Ranging. The term has since entered CFR part 43, appendix A. Certificated pilots may perform the English language as a standard word, radar, losing the preventive maintenance on any aircraft that is owned or capitalization in the process. operated by them provided that the aircraft is not used in air carrier service. Radar approach. The controller provides vectors while monitoring the progress of the flight with radar, guiding Primary and supporting. A method of attitude instrument the pilot through the descent to the airport/heliport or to a flying using the instrument that provides the most direct specific runway. indication of attitude and performance. Radar services. Radar is a method whereby radio waves are Primary flight display (PFD). A display that provides transmitted into the air and are then received when they have increased situational awareness to the pilot by replacing the been reflected by an object in the path of the beam. Range is traditional six instruments used for instrument flight with determined by measuring the time it takes (at the speed of light) an easy-to-scan display that provides the horizon, airspeed, for the radio wave to go out to the object and then return to the altitude, vertical speed, trend, trim, and rate of turn among receiving antenna. The direction of a detected object from a other key relevant indications. radar site is determined by the position of the rotating antenna when the reflected portion of the radio wave is received. PRM. See precision runway monitor. Radar summary chart. A weather product derived from the Procedure turn. A maneuver prescribed when it is necessary national radar network that graphically displays a summary to reverse direction to establish an aircraft on the intermediate of radar weather reports. approach segment or final approach course. Radar weather report (SD). A report issued by radar Profile view. Side view of an IAP chart illustrating the vertical stations at 35 minutes after the hour, and special reports approach path altitudes, headings, distances, and fixes. as needed. Provides information on the type, intensity, and location of the echo tops of the precipitation. Prohibited area. Designated airspace within which flight of aircraft is prohibited. Radials. The courses oriented from a station. Propeller. A device for propelling an aircraft that, when Radio or radar altimeter. An electronic altimeter that rotated, produces by its action on the air, a thrust approximately determines the height of an aircraft above the terrain by perpendicular to its plane of rotation. It includes the control measuring the time needed for a pulse of radio-frequency components normally supplied by its manufacturer. energy to travel from the aircraft to the ground and return. Propeller/rotor modulation error. Certain propeller Radio frequency (RF). A term that refers to alternating rpm settings or helicopter rotor speeds can cause the VOR current (AC) having characteristics such that, if the current is course deviation indicator (CDI) to fluctuate as much as input to antenna, an electromagnetic (EM) field is generated ±6°. Slight changes to the rpm setting will normally smooth suitable for wireless broadcasting and/or communications. out this roughness. G-24