H
hail |noun| precipitation as small pellets of ice / Precipitation is the falling of water, as rain, sleet, snow or hail onto the surface of the earth. Although hail, and in particular, heavy hail is rare and of short duration, damage to an aircraft may be severe. / (NOTE: In weather reports and forecasts, hail is indicated by the abbreviation ‘GR’.)
hailstone |noun| a small pellet of ice which falls from clouds / A hailstone starts as a small ice particle in the upper portion of a cumulonimbus cloud. /
hailstorm |noun| a storm, where the precipitation is hail instead of rain or snow / Flying through the hailstorm damaged the leading edges. /
hand flying |noun| flying an aircraft by moving the flight controls with the hands rather than by using the autopilot
hand-held |adjective| possible to hold in the hand / Nowadays, headsets are usually used in preference to hand-held microphones. /
handle |noun| a device for holding, or being operated, by the hand - |verb| 1. to touch with the hands / Cabin staff should not handle unwrapped food which is to be served to passengers. / 2. to move or operate by hand / The student pilot handled the aircraft well in the turbulent conditions. / 3. to deal with, or to manage / Flight crew must be able to handle any emergency when it occurs. /
handling |noun| 1. the act of touching with the hands 2. the use of the hands to move or operate something - aircraft handling > the act of maneuvering the aircraft in the desired manner 3. the act of dealing with or managing something / Her handling of a difficult situation won the admiration of the whole crew. /
hand luggage |noun| small bags that passengers can take with them into the cabin of an aircraft / The amount of hand luggage is limited to one bag. /
handoff |noun| a transfer of a flight from one controller or area to another. Also called: handover
handover |noun| a transfer of a flight from one controller or area to another. Also called: handoff
hand signals |plural noun| same as marshaling signals
hands off |adjective|,|adverb| where the operator does not control the operation, which is automatic / Automatic flight control system capable of landing an aircraft hands off. /
hangar |noun| a large shelter for housing and maintaining aircraft / Light aircraft should be left with parking brakes off so that they can be moved quickly in the event of a fire in the hangar. /
hard copied |verb| written in note from a radio transmission. / More complex clearances, instructions and terminal information are hard copied by the crew in the form of written notes. /
hard landing |noun| an uncontrolled landing by an aircraft that results in its being damaged or destroyed
hardly |adverb| scarcely, almost not at all / There was hardly any damage caused to the fuselage when the catering truck skidded on the ice and failed to stop in time. /
haul |noun| - long-haul, short-haul
hazard |noun| a possible danger / Thunderclouds are of special interest to aircrew because of the hazards they may pose to aircraft in flight. /
hazardous |adjective| possibly risky or dangerous / Flying over mountainous terrain can be hazardous. Structural icing is a hazardous phenomenon for rotary wing as well as fixed wing aircraft. /
haze |noun| dust or smoke in the atmosphere / Haze can seriously reduce air-to-ground visibility. /
head |noun| 1. the top part of the body above the shoulders 2. a person - head count > an easy way of counting large numbers of people 3. a main end part or top of something 4. a leader, chief or director - head of department > the most senior person in the department - |verb| to fly in a particular direction - head north > to fly towards the north
heading |noun| the direction in which the longitudinal axis of the aircraft is pointing, expressed in degrees from north (NOTE: Wind affects an aircraft in flight, therefore heading does not always coincide with the aircraft’s track. The pilot must head the aircraft slightly into the wind to correct for drift.)
heading bug |noun| a movable plastic marker on the horizontal situation indicator
heading correction |noun| a change of heading in order to deal with a new situation. Also called: course correction
heading indicator |noun| an instrument which gives course or direction information e.g. a horizontal situation indicator (HSI) or direction indicator (DI) (NOTE: The heading indicator is driven by a gyro and provides steady, exact indications of heading.)
heading to steer |noun| a gyro-compass point in which to direct the aircraft
head-on |adjective|,|adverb| - to approach head-on > to approach from opposite directions
head-on collision |noun| a collision between two things or vehicles coming from opposite directions
headphones |noun| small speakers with padding, worn over a person’s ears, used for private listening / Headphones are used to monitor the signal. /
headset |noun| headphones with a microphone attached, used for RT communications / Headsets are usually used in preference to hand-held microphones. /
head-up display |noun| a cockpit system where data from flight instruments is projected onto a screen or the windscreen so that the pilot can see it without having to look down. Abbreviation: HUD
headwind |noun| a wind which is blowing in the opposite direction to the direction of movement or flight. (NOTE: The word is also written head wind.)
headwind component |noun| one of the three possible components of a wind, the other two being crosswind and tailwind
heap |noun| a group of things piled or thrown one on top of another
heap cloud |noun| same as cumulus cloud
hearback error |noun| a failure to notice when one’s own error is correctly repeated by the interlocutor
heat |noun| warmth, being hot / The heat generated by combustion is considerable. / - |verb| to make warm or warmer / The air leaving the turbocharger is very warm and can be used to heat the cabin. /
heater |noun| a device for heating / Pitot heads contain heater elements to prevent icing. /
heating |noun| the process of making something warmer
heavier-than-air |adjective| weighing more than the air it displaces, and so needing power to fly
heavy |adjective| having a lot of weight - a heavy load > a load of great weight - heavy rain > rain which is dense and distributes a lot of water over the surface of the Earth in a relatively short time
heavy-duty |adjective| referring to something designed for hard wear or use / Longerons are heavy-duty steel members. /
heavy landing |noun| a routine landing in which the aircraft makes contact with the surface with more force than usual, thereby possibly causing damage to the undercarriage / The pilot reported a heavy landing. /
hectoPascal |noun| the most common unit of atmospheric pressure; in the plural, it does not take an ‘s’: 1021 hectoPascal. It is the equivalent of millibars (mb), which is still referred to in many countries. Inches of Mercury (in.Hg) is used in the United States. 1 in.Hg = 3.386 hPa
hedgehop |verb| to fly at very low height above the ground
height |noun| the vertical distance of a point, level or object measured from a particular point, e.g. sea level / Pressure decreases with increasing height. / - height of the aircraft > the vertical distance, measured in feet, of the aircraft above the surface of the earth
heli |noun| a rotary-wing aircraft
heliborne |adjective| transported by helicopter
helicopter |noun| an aircraft with one or more rotors rotating around vertical axes which provide lift and control / Helicopter operations are carried out at the airport. /
helicopter rotor |noun| two or more rotating blades, known as the main rotor, which provide lift and thrust for a helicopter
helideck |noun| a deck on something such as a ship or offshore oil platform that is used as a landing area for helicopters
heliograph |noun| an instrument with a mirror to send messages by reflecting the sun / Heliographs enable reflected sunlight to be directed to a ship or aircraft in periods of direct sunlight. /
helipad |noun| an area where helicopters take off and land
heliport |noun| an airport designed for helicopters
helistop |noun| a place where helicopters can take off and land, but usually one that does not have the support facilities found at a heliport
helo |noun| 1. a rotary-winged aircraft 2. same as heliport
hemisphere |noun| half a sphere
Hercules |noun| a Lockheed C-130, four engine turboprop military transport plane
Hertz |noun| the SI unit of frequency, defined as the number of cycles per second of time. Abbreviation: Hz
HF |abbreviation| high frequency
high |adjective| 1. having great vertical distance 2. great, large, a lot - high engine rpm > fast engine speed - high pressure > a lot of pressure - high reliability > good reliability - high speed > a fast speed - high temperature > a hot temperature - |noun| an area of high atmospheric pressure / There is a high over the British Isles. /
high frequency, high frequency band |noun| a radio communications range of frequencies between 3–30 MHz. Abbreviation: HF
High Intensity Runway Lighting |noun| / The brightness of runway lighting can be adjusted by the Tower according to the atmospheric conditions and time of day. /
high-performance |adjective| a system which provides better-than-usual output / Some high-performance engines have coolant and oil system thermostats which aid warming-up. /
high performance aircraft |noun| an aircraft capable of flying faster, higher or with more maneuverability than normal aircraft
high-speed approach |noun| an approach at a higher than normal airspeed using a flaps-up (clean) aircraft configuration in order to expedite arrival
high-speed exit |noun| an angled taxiway allowing aircraft to vacate runway without decelerating completely
high-speed tug |noun| a tow vehicle used to tow aircraft over long distances
hijack |verb| to take over control of an aircraft by one or several unauthorized person or persons with the intention of forcing the crew to fly it to a different destination / The airliner was hijacked on its way to Paris. /
hijacker |noun| a person who hijacks an aircraft or other vehicle
hijacking |noun| the act of taking over control of an aircraft by one or several unauthorized person or persons with the intention of forcing the crew to fly it to a different destination / The crew must be alert at all times to the possibility of hijacking, bombs and stowaways. /
hill |noun| an easily-seen, natural elevation, smaller than a mountain / Slopes on the side of a hill or mountain facing away from the sun receive less intense radiation. Hill shading is produced by assuming that bright light is shining across the chart sheet so that shadows are cast by the high ground. /
hinder |verb| to make it difficult for something to happen / Free flow of fuel may be hindered by a blockage in the fuel line. Her illness hindered his progress on the course. /
hinge |noun| a device which allows a door, flap or lid to open and close on a stationary frame / Flying control hinges should be inspected before flight. / - |verb| to move against a stationary frame / Access to the engine compartment is normally via hinged cowling panels. /
HIRF |abbreviation| high-intensity radiated fields
HIRL |abbreviation| High Intensity Runway Lighting
HMR |abbreviation| helicopter main route
hoar, hoar frost |noun| a frozen dew which forms on outside surfaces when the temperature falls below freezing point / Rapid descent from cold altitudes into warm moist air may produce hoar frost on the aircraft. /
hold |noun| an area or compartment within the aircraft for carrying freight / Carry-on baggage is limited by regulations as to size and weight and items in excess of this should be stowed in the luggage hold. / - |verb| 1. to keep and prevent from moving / The function of the autopilot system is to hold the aircraft on a desired flight path by means of gyroscopes and/or accelerometers. If the operating pressure falls or fails, a mechanical lock holds the reverser in the forward thrust position. / 2. to keep an aircraft in a particular position on the ground or in the air while waiting for further clearance from air traffic control / It is normal practice for ATC to hold taxiing aircraft well clear of the glide path and localiser antenna when visibility is poor. / 3. to have and keep in the hand / Hold the microphone in your right hand. / - hand-held > possible to hold in the hand / Nowadays, headsets are usually used in preference to hand-held microphones. / 4. to have (NOTE: holding – held) - he holds an IMC rating > he has an IMC rating
hold short of |verb| to stop and wait just before you get to a location / hold short of Runway 33 Left /
holder |noun| 1. a device for holding something 2. a person who has a particular title or qualification
holding fuel |noun| extra fuel carried by an aircraft to allow for time spent in the hold waiting for air traffic control clearance
holding pattern |noun| a racetrack-shaped flight pattern with two parallel sides and two turns, flown usually while an aircraft is waiting for clearance to land
holding point |noun| 1. a particular location, in the air or on the ground where aircraft spend time, waiting for further clearance from air traffic control 2. a place, often designated Alpha, Bravo, Charlie, etc., where aircraft wait before entering the runway, as instructed by air traffic control
holding stack |noun| an area of airspace where planes are instructed to wait before landing if there are delays (NOTE: Aircraft circle and descend according to the controller’s instructions until they are released from the lowest height in the stack for their final approach to the airport.)
hollow |adjective| having a space within, not solid
home |noun| the home airfield - home airfield > the airfield which one returns to after a two-leg flight
homeward |adjective| going towards home - |adverb| - homeward bound > heading towards home
homewards |adverb| towards home / They were heading homewards when the accident happened. /
homing |noun| a flight towards or away from a radio station while using direction finding equipment / Where an RBI is fitted, homing to an NDB can be made by initially turning the aircraft until the relative bearing is zero. /
homogeneous |adjective| of the same kind / If the air over a large region were homogeneous, there would be no horizontal differences in surface temperature. The atmosphere is not homogeneous – pressure, temperature and humidity can all change with height. /
hop |noun| a flight or section of a flight in an aircraft (informal)
horizon |noun| the line where the sky and the ground appear to join - visual horizon > a horizon which can be seen
horizontal |adjective| parallel to the horizon, or at right angles to the vertical / The horizontal motion of air is known as wind. /
horizontal axis |noun| a horizontal reference line of a graph / The plot shows the effect of airspeed on lift with airspeed shown on the horizontal axis and lift on the vertical axis. /
horizontal separation |noun| the horizontal distance between two aircraft, which is measured in meters or kilometers
horizontal situation indicator |noun| a cockpit instrument which gives the pilot information about the direction of the aircraft’s flight path / On the aircraft, the horizontal situation indicator is located on the instrument panel below the attitude indicator. / Abbreviation: HSI (NOTE: The horizontal situation indicator combines the function of the heading indicator and a VOR/ILS display.)
horizontal stabilizer |noun| a tailplane / The horizontal stabilizer provides stability about the lateral axis of the aircraft. /
horn |noun| a device for projecting sound - warning horn > device which emits a loud warning noise
horn balance |noun| part of a control surface forward of the hinge line which reduces the force needed by the pilot to move the surface
horsepower |noun| the accepted unit for measuring the rate of doing work / Horsepower is defined as 33,000 foot-pounds of work done in one minute. / Abbreviation: h.p., HP
hose |noun| a long, flexible pipe usually made of fabric, plastic or rubber for pumping gases or liquids - refueling hose > a flexible pipe used to pump fuel from the bowser to the aircraft
hot |adjective| very warm, having a high temperature - hot air > air introduced to melt ice forming in the carburetor in a piston engine aircraft - hot section > the section of the engine comprising the combustion chamber, high and low pressure turbines and exhaust
hot spot |noun| an intersection indicated on an aerodrome chart where the risk of collisions and incursions is high
hour |noun| 1. a period of time which lasts sixty minutes / It’s a three-hour flight to Greece from London. / 2. a method of indicating time / Flight BA 321 landed at Heathrow at 10.30 hours. /
house |verb| to contain or accommodate / The areas between the ribs in the wings are utilized to house fuel tanks. The wing tips house the navigation lights. /
housing |noun| a compartment or container / The crankcase is the housing that encloses the various mechanical parts surrounding the crankshaft. / - engine housing > engine compartment
hover |verb| to remain stationary, relative to the earth, while in the air - |noun| a period of stationary flight / During a hover, helicopter pilots must be able to coordinate movements of both hands and feet. /
hovercraft |noun| a vehicle that can travel over land and water supported on a cushion of air that is produced by a powerful engine that blows air downwards. Also called: air cushion vehicle, ground effect machine
how do you read? |phrase,question| ‘how clear is my transmission?’
however |adverb| but / The wind was gusty, however the landing was good. The incident was serious, however she escaped with only a warning. /
hrs |abbreviation| hours
HSI |abbreviation| horizontal situation indicator
hub |noun| a major airport where international or long-distance flights take off and land
hub airport |noun| same as hub
HUD |abbreviation| head-up display
human factors |noun| the study of the way in which humans handle, and react to, things in their environment. It is used in aviation to develop safer systems and procedures. (NOTE: Human factors is followed by a verb in the singular.)
human remains |plural noun| a corpse, dead body transported in a coffin
humid |adjective| containing a lot of water vapor - humid weather > weather which, although warm, feels damp and uncomfortable
humidity |noun| a measurement of how much water vapor is contained in the air - the humidity is high > there is a lot of moisture or water vapor in the air
hydraulic |adjective| referring to any system or device which uses fluids such as oil to transmit a force from one place to another using pipes
hydraulic fluid |noun| thin oil used in hydraulic braking systems, etc.
hydraulic pressure |noun| the pressure exerted by hydraulic fluid
hydraulic problem |noun| a malfunction or a failure (leaks, loss of pressure, filter clogging, pump failure etc.) on a hydraulic system. Several aircraft systems depend on hydraulic power: flight controls, landing gear, brakes, thrust reversers. However, most commercial aircraft have triplexed hydraulic systems, i.e. three separate hydraulic systems, at least two of which supply each hydraulically driven component. However, the complete loss of a system can cause the secondary flight controls (flaps, slats) to be downgraded and also affect aircraft braking. If the flaps are not fully extended, the aircraft will land faster and so will require a longer stopping distance. If there is not full braking capability, braking will be less effective and again the stopping distance will be increased.
hydraulic tubing |noun| system of tubes or thin pipes connecting the main components of a hydraulic system
hydro- |prefix| water / a hydro-mechanical governor /
hygrometer |noun| an instrument used for the measurement of humidity / The most common type of hygrometer is the wet and dry bulb thermometer arrangement. /
hypoxia |noun| a medical condition in which not enough oxygen is supplied to the body / The symptoms of hypoxia are sometimes difficult to detect. / (NOTE: Cabin pressurization or oxygen equipment is usually required for flying at altitudes at or above about 10,000 ft (3,048 m).)
Hz |abbreviation| Hertz
