Devenition And Abreviation Aeronautical Telecommunication (Alphabet H)

Hazard beacon. An aeronautical beacon used to designate a danger to air navigation. 

He or She (unless specified), taken in context with that section. 

His or Hers (unless specified), taken in context with that section. 

Heaver-than-air. Any aircraft deriving its lift in flight chiefly from aerodynamic forces. 

Heading. The direction in which the longitudinal axis of an aircraft is pointed, usually expressed in degrees from North (true, magnetic, compass or grid). 

Height. The vertical distance of a level, a point or an object considered as a point, measured from a specified datum. 

Helicopter means a rotorcraft that, for its horizontal motion, depends principally on its engine driven rotors or an aircraft which is heavier than air, capable of flying with rotary wings, and travels by its own power. 

Helicopter clearway. A defined area on the ground or water under the control of the appropriate authority, selected and/or prepared as a suitable area over which a performance class 1 helicopter may accelerate and achieve a specific height. 

Helicopter ground taxiway. A ground taxiway for use by helicopters only.  

Helicopter stand. An aircraft stand which provides for parking a helicopter and, where air taxiing operations are contemplated, the helicopter touchdown and lift-off. 

Helideck. A heliport located on a floating or fixed off-shore structure. 

Heliport means :
(1) An area of land, water, or structure used or intended to be used for the landing 

     and takeoff of helicopters.
(2) An aerodrome or a defined area on a structure intended to be used wholly or in part for

     the arrival, departure and surface movement of helicopters.
 

Heliport operating minima. The limits of usability of a heliport for: 

a) take-off, expressed in terms of runway visual range and/or visibility and, if necessary, 

    cloud conditions; 

b) landing in precision approach and landing operations, expressed in terms of visibility and/or 

    runway visual range and decision altitude/height (DA/H) as appro-priate to the 

    category of the operation; 

c) landing in approach and landing operations with vertical guidance, expressed in terms 

    of visibility and/or runway visual range and decision altitude/height (DA/H); and 

d) landing in non-precision approach and landing operations, expressed in terms of visibility

    and/or runway visual range, minimum descent altitude/height (MDA/H) and, if necessary, 

    cloud conditions. 

Henry (H). The inductance of a closed circuit in which an electromotive force of 1 volt is produced when the electric current in the circuit varies uniformly at a rate of1 ampere per second.
 

Hertz (Hz). The frequency of a periodic phenomenon of which the period is 1 second. 

Holding bay. A defined area where aircraft can be held, or bypassed, to facilitate efficient surface movement of aircraft. 

Holding procedure. A predetermined manoeuvre which keeps an aircraft within a specified airspace while awaiting further clearance. 

Holdover time. The estimated time the anti-icing fluid (treatment) will prevent the formation of ice and frost and the accumulation of snow on the protected (treated) surfaces of an aeroplane. 

Hovering is a maneuver in which the helicopter is maintained in nearly motionless flight over a reference point at a constant altitude and on a constant heading. The maneuver requires a high degree of concentration and coordination. 

Hovering autorotation means the maneuver is used to land from a hover without using the engine. This would normally occur because the engine or tail rotor failed. Hovering autorotation is really a misnomer, because the helicopter actually never enters autorotation. Instead, the inertia of the spinning rotor system is used to produce thrust. 

Human performance. Human capabilities and limitations which have an impact on the safety and efficiency of aeronautical operations. 

Human Factors principles. Principles which apply to aeronautical design, certification, training, operations and maintenance and which seek safe interface between the human and other system components by proper consideration to human performance. 

Hypsometric tints. A succession of shades or colour gradations used to depict ranges of elevation.