horn balance /h.n bl(.)ns/
noun part of a control surface forward of the hinge line which reduces the force needed by the pilot to move the surface
horsepower /h.spaυ./ 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 /h.υz/ noun a long, flexible pipe usually made of fabric, plastic or rubber for pumping gases or liquids . refuel-ling hose a flexible pipe used to pump fuel from the bowser to the aircraft
hot /h.t/ adjective very warm, having a high temperature . hot weather . hot air air introduced to melt ice forming in the carburettor in a piston engine air-craft
hour /aυ./ 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 /haυz/ verb to contain or accommodate . The areas between the ribs in the wings are utilised to house fuel tanks. . The wing tips house the navigation lights.
housing /haυz../ noun a compart-ment or container . The crankcase is the housing that encloses the various mechanical parts surrounding the crankshaft. . engine housing engine compartment
hover /h.v./ verb to remain station-ary, 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 /h.v.krɑft/ 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
however /haυev./ adverb but . The
wind was gusty, however the landing was good. . The incident was serious, however she escaped with only a warn-ing.
hrs abbreviation hours
HSI abbreviation horizontal situation indicator hub /hb/ noun a major airport where
international or long-distance flights take off and land

hub airport 114
hub airport /'hAb ，e.p.:t / noun same as hub HUD abbreviation head-up display human factors /，hju:m.n 'f.kt.z /
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 proce-dures. (NOTE: Human factors is followed by a verb in the singular.)
humid /'hju:m.d/ adjective contain-ing a lot of water vapour 口 humid weather weather which, although warm, feels damp and uncomfortable
humidity /hju:'m.d.ti/ noun a meas-urement of how much water vapour is contained in the air 口 the humidity is high there is a lot of moisture or water vapour in the air
hydraulic /ha.'dr.:l.k/ adjective
referring to any system or device which uses fluids such as oil to transmit a force from one place to another using pipes 0 a hydraulic pump