- radio telephony. Voice communications, as opposed to WT,
wireless telegraphy. Also styled RTF.
rabbit lights - colloquialism for sequentially flashing lead-in
runway approach lights.
RAF - Royal Air Force
ramp weight - maximum permissible weight of an aircraft, which
exceeds maximum take-off weight by an allowance for fuel burned during
engine-start and taxi.
RAPID - change expected to take place in thirty minutes or
less, term used in mer reports.
RAS (1) - rectified airspeed. Indicated airspeed corrected for
instrument position error.
RAS (2) - Radar Advisory Service. Provided outside regulated
airspace to notify pilots of conflicting traffic and to advise
suitable avoiding action. Also RASA Radar Advisory Service Area.
rating - add-on qualification to a pilot's licence, e.g. Night
Rating, Multi-engine Rating, Instrument Rating, Seaplane Rating etc.
Individual Type Ratings are necessary to fly aircraft over 12,500
RBI - relative bearing indicator, displaying information from
RCL - runway centre-line.
RDO - radio.
RIS - Radar Information Service. Provided to notify pilots of
conflicting traffic outisde regulated airspace, but offering no
RMI - radio magnetic indicator. A navigation aid which combines
DI, VOR and/or ADF display and will indicate bearings to stations,
together with aircraft heading.
RMK - remark(s).
RMU - radio management unit.
Rnav - area navigation. A system of radio navigation which
permits direct point-to-point off-airways navigation by means of an
on-board computer creating phantom VOR/DME transmitters termed
RON - remain over night (night-stop).
root - inner end of wing where it meets fuselage.
rpm - revolutions per minute.
RVR - runway visual range, a horizontal measurement of
visibility along a runway.
rwy - runway.
Rx - receiver.