the online flight safety digest
Glossary of Aviation & Technical Terms
The following Glossary contains brief definitions of terms and acronyms used in Gremline articles. Many of our readers will be familiar with most, if not all, of the aviation and technical terms used on this site. New entrants to the world of aviation and casual readers may feel less confident when confronted with the plethora of acronyms, etc., that are the shorthand of the initiated. Our Glossary will be updated as more articles are added and as the breadth of technical coverage expands.
AAIB: Air Accidents Investigation Branch (UK).
ABS: automatic braking system.
AFIS(O): Aerodrome Flight Information Service (Officer).
AFS: Aerodrome Fire Service.
agl: above ground level.
AME: Aviation Medical Examiner.
amsl: above mean sea level.
APU: auxiliary power unit (normally used during engine start).
ATC: Air Traffic Control.
ATCC: Air Traffic Control Centre.
BCAR: British Civil Airworthiness Requirements (UK).
CAA: Civil Aviation Authority (UK).
CAP: Civil Aviation Publication (UK).
CFIT: Controlled Flight Into Terrain.
CG: Centre of Gravity.
Cold Shock: The loss of body functions, or death, immediately on sudden immersion in very cold water. See also Hypothermia and Vasogenic Shock.
Controlled Airspace: Airspace closed to unauthorised aircraft (and see TPA).
CVR: Cockpit Voice Recorder.
°C, F, M, T: degrees Celsius, Fahrenheit, magnetic, true.
D&D Cell: Distress and Diversion Cell (at ATCC listening out on 121.5Mhz and 243Mhz).
Dewpoint: The OAT at which the airmass reaches saturation point.
DME: Distance Measuring Equipment.
ETA: estimated time of arrival.
ETD: estimated time of departure.
gremlin: (RAF slang) Mischievous sprite imagined to frequent aircraft and to cause mishaps [OED].
Ground Effect: The effect of ground interference on the airflow patterns around an aircraft when the aircraft is close to the ground.
HASELL Check: Cockpit checks prior to stall/spin, aerobatics, (practice) forced landing.
Hypothermia: The decrease of core body temperature to a level at which normal muscular and cerebral functions are impaired (and see Cold Shock and Vasogenic Shock).
IAS: indicated airspeed.
IMC Rating: Instrument Met. Conditions rating (peculiar to UK and invalid elsewhere).
JAR-OPS: Joint Airworthiness Requirements – Operations (European Union regulations).
KIAS: knots indicated airspeed.
LAMS: Light Aircraft Maintenance Schedule (UK).
LASORS: Licensing, Administration, Standardisation, Operating Requirements and Procedures (UK).
Lexicographer: “A writer of dictionaries [or glossaries?], a harmless drudge.” Samuel Johnson.
LDA: Landing Distance Available.
LTE: Loss of Tail Rotor Effectiveness in helicopters. A low speed aerodynamic characteristic that can result in an uncommanded rapid yaw rate that does not subside of its own accord. Also known as ‘unanticipated yaw’ or ‘loss of tail rotor authority’.
METAR: Meteorological Airfield Report.
MRT: Mountain Rescue Team.
MTWA: Maximum Total Weight Authorised.
MTOW: Maximum Take-off Weight.
MOGAS: motor gasoline (as distinct from AVGAS).
OAT: Outside Air Temperature.
PAPI: Precision Approach Path Indicator.
PAR: Precision Approach Radar.
PIO: Pilot Induced Oscillation.
QNH: altimeter setting to indicate height amsl.
RCC: Rescue Co-ordination Centre.
SAFETYCOM: Frequency for use in certain circumstances by aircraft operating in the vicinity of UK aerodromes and landing sites that do not have a frequency assigned for communication. Introduced on 11 November 2004. Full details can be found on the Civil Aviation Authority web site at www.caa.co.uk.
Slow Flying: Flight at any airspeed less than Endurance Speed (q.v.).
SSLs: Safety Sense Leaflets, published by the UK Civil Aviation Authority.
STOL: Short Takeoff & Landing
TAF: Terminal Airfield Forecast.
TAS: true airspeed.
TODR: Take-off Distance Required.
TORA: Take-off Run Available.
TORR: Take-off Run Required.
TPA: Temporary Prohibited Area. Airspace closed to unauthorised aircraft (and see Controlled Airspace).
Thermal Runaway: In batteries. Can occur if rating capacities are exceeded. Involves violent gassing, boiling of the electrolyte, damage to the plates and even melting of the battery case or explosion.
Unanticipated Yaw: In helicopters. See LTE – Loss of Tail Rotor Effectiveness.
UCT: Universal Co-ordinated Time (replacing Greenwich Mean Time).
Vasogenic Shock: When the body is immersed in water in a vertical position for some time, the water pressure reduces the tendency for blood to pool in the lower limbs, keeping the blood pressure higher in the body core. When the body is lifted vertically from the water the blood rushes downwards into the legs causing a drop in blood pressure that can lead to heart failure. Winchmen will therefore try to lift survivors out of the water in a horizontal position. And see Hypothermia and Cold Shock.
Va: design manoeuvring speed (or turbulence penetration speed).
Venturi Effect: Increase in the speed of flow of gasses or liquids caused by a constriction or bend in the containing duct.
VFR: Visual Flight Rules.
VMC: Visual Meteorological Conditions.
Vne: never exceed speed.
VOLMET: Voice Met. Broadcast.
VRP: Visual Reporting Point.
VSI: vertical speed indicator.
Vy: speed for best RATE of climb.
Vx: speed for best ANGLE of climb.
WAT: Weight, Altitude, Temperature. Variables that affect takeoff performance.
Text and Photographs © 2007 Gremline & Hill House
Publications, unless otherwise stated.
Text and Photographs © 2007 Gremline & Hill House Publications, unless otherwise stated.
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