Definitions — Page 46, Lesson 35

I want to walk you through the definitions section of your communications manual. This is a reference list of standard aviation abbreviations and acronyms that you'll see on charts, in messages, and in operational documents. Let's go through them in order. Starting with the letter P. POSS stands for "Possible" — used in weather or operational reports to indicate something may occur. PPI is "Plan Position Indicator" — that's the circular radar display showing aircraft positions around the station. PPR means "Prior Permission Required" — you need advance approval to land at certain aerodromes. PPSN is "Present Position" — your current location. PRI is "Primary" — as in primary radar or primary frequency. PRKG is "Parking." PRM is "Preferred Route Message" — a filed route that ATC prefers you to use. PROB with a dagger symbol means "Probability" — used in forecasts to indicate the likelihood of a weather phenomenon. PROC is "Procedure." PROV is "Provisional" — temporary or not yet final. PS is "Plus" — as in plus something. PSG is "Passing" — used when reporting crossing a level or fix. PSN is "Position." PSP is "Pierced Steel Plan" — a type of temporary runway surface. PTN is "Procedure Turn" — a manoeuvre to reverse course during an instrument approach. PTS is "Polar Track Structure" — a route structure used in polar operations. PWR is "Power." Now the Q codes. These are three-letter codes starting with Q, used historically in radiotelegraphy and still in use today. QBI means "Compulsory IFR flight" — when IFR is mandatory. QDM with a double-dagger symbol is "Magnetic Heading (zero wind)" — the magnetic heading you'd steer to fly directly to a station with no wind. QDR is "Magnetic Bearing" — the magnetic bearing from the station to your aircraft. QFA is "Meteorological Forecast." QFE with a double-dagger is "Atmospheric pressure at aerodrome elevation (OR at runway threshold)" — set this on your altimeter subscale, and the altimeter reads height above that datum. QFU is "Magnetic orientation of runway" — the runway's magnetic direction. QNH with a double-dagger is "Altimeter subscale setting to obtain elevation when on the ground" — set this, and your altimeter reads altitude above mean sea level. QTE is "True bearing" — the true bearing from the station to your aircraft. QUAD is "Quadrant." Moving to R. R alone can mean "Red" — as in a light colour. R followed by an identification is "Restricted Area" — airspace with restrictions. R used as a prefix in graphics means "Radial" — a magnetic bearing from a VOR station. R in runway identification means "Right" — as in runway 27 Right. R can also mean "Rate of Turn." RA is "Rain." RA also means "Resolution Advisory/Advisories" from ACAS — the traffic collision avoidance system's guidance to resolve a conflict. RAC is "Rules of the Air and Air Traffic Services." RAD is "Radar Approach Aid" and also "Radius." RAF is "Royal Air Force." RAFC is "Regional Area Forecast Centre." RAG is "Ragged" — describing cloud or weather, and also "Runway Arresting Gear" — the cable system to stop an aircraft. RAI is "Runway Alignment Indicator." RAL is "Runway alignment beacon at distance from beacon threshold indicated" — a beacon showing the runway alignment. RAS is "Radar Advisory Service." RB is "Rescue Boat." RCA is "Reach Cruising Altitude." RCC is "Rescue Coordination Centre." RCF is "Radio Communication Failure" — a message type designator. RCH is "Reach OR Reaching." RCL is "Runway Centre Line." RCLL is "Runway Centre Line Light(s)." RCLR is "Recleared." RDH is "Reference Datum Height" for ILS — the height of the ILS glidepath reference point above the threshold. RDL is "Radial." Continuing with R. RDT is "Requested Departure Time." RDO is "Radio." RE with an ellipsis means "Recent" — used to qualify weather phenomena, for example RERA means "Recent Rain." REC is "Receive OR Receiver." REDL is "Runway Edge Light(s)." REF is "Reference to ... OR Refer to ..." REG is "Registration" — the aircraft's registration mark. These abbreviations are the standard shorthand you'll use in flight plans, NOTAMs, weather reports, and radio communications. You need to know them cold — not just what the letters stand for, but what each one means operationally.