HAA- (See HEIGHT ABOVE AIRPORT.)
HAL- (See HEIGHT ABOVE LANDING.)
HANDOFF- An action taken to transfer the radar identification of an aircraft from one controller to another if the aircraft will enter the receiving controller's airspace and radio communications with the aircraft will be transferred.
HAT- (See HEIGHT ABOVE TOUCHDOWN.)
HAVE NUMBERS- Used by pilots to inform ATC that they have received runway, wind, and altimeter information only.
HAZARDOUS INFLIGHT WEATHER ADVISORY SERVICE- Continuous recorded hazardous inflight weather forecasts broadcasted to airborne pilots over selected VOR outlets defined as an HIWAS BROADCAST AREA.
HAZARDOUS WEATHER INFORMATION- Summary of significant meteorological information (SIGMET/WS), convective significant meteorological information (convective SIGMET/WST), urgent pilot weather reports (urgent PIREP/UUA), center weather advisories (CWA), airmen's meteorological information (AIRMET/WA) and any other weather such as isolated thunderstorms that are rapidly developing and increasing in intensity, or low ceilings and visibilities that are becoming widespread which is considered significant and are not included in a current hazardous weather advisory.
HEAVY (AIRCRAFT)- (See AIRCRAFT CLASSES.)
HEIGHT ABOVE AIRPORT- The height of the Minimum Descent Altitude above the published airport elevation. This is published in conjunction with circling minimums.
HELIPAD- A small, designated area, usually with a prepared surface, on a heliport, airport, landing/takeoff area, apron/ramp, or movement area used for takeoff, landing, or parking of helicopters.
HELIPORT- An area of land, water, or structure used or intended to be used for the landing and takeoff of helicopters and includes its buildings and facilities if any.
HELIPORT REFERENCE POINT (HRP)- The geographic center of a heliport.
HERTZ- The standard radio equivalent of frequency in cycles per second of an electromagnetic wave. Kilohertz (kHz) is a frequency of one thousand cycles per second. Megahertz (MHz) is a frequency of one million cycles per second.
HF- (See HIGH FREQUENCY.)
HF COMMUNICATIONS- (See HIGH FREQUENCY COMMUNICATIONS.)
HIGH FREQUENCY- The frequency band between 3 and 30 MHz.
HIGH SPEED EXIT- (See HIGH SPEED TAXIWAY.)
HIGH SPEED TAXIWAY- A long radius taxiway designed and provided with lighting or marking to define the path of aircraft, traveling at high speed (up to 60 knots), from the runway center to a point on the center of a taxiway. Also referred to as long radius exit or turn-off taxiway. The high speed taxiway is designed to expedite aircraft turning off the runway after landing, thus reducing runway occupancy time.
HIGH SPEED TURNOFF- (See HIGH SPEED TAXIWAY.)
HIWAS- (See HAZARDOUS INFLIGHT WEATHER ADVISORY SERVICE.)
HIWAS AREA- (See HAZARDOUS INFLIGHT WEATHER ADVISORY SERVICE.)
HIWAS BROADCAST AREA- A geographical area of responsibility including one or more HIWAS outlet areas assigned to an AFSS/FSS for hazardous weather advisory broadcasting.
HIWAS OUTLET AREA- An area defined as a 150 NM radius of a HIWAS outlet, expanded as necessary to provide coverage.
HOLDING PROCEDURE- (See HOLD PROCEDURE.)
HOLD PROCEDURE- A predetermined maneuver which keeps aircraft within a specified airspace while awaiting further clearance from air traffic control. Also used during ground operations to keep aircraft within a specified area or at a specified point while awaiting further clearance from air traffic control.
HOLDING FIX- A specified fix identifiable to a pilot by NAVAID's or visual reference to the ground used as a reference point in establishing and maintaining the position of an aircraft while holding.
HOLD FOR RELEASE- Used by ATC to delay an aircraft for traffic management reasons; i.e., weather, traffic volume, etc. Hold for release instructions (including departure delay information) are used to inform a pilot or a controller (either directly or through an authorized relay) that an IFR departure clearance is not valid until a release time or additional instructions have been received.
HOLD-SHORT POSITION LIGHTS- Flashing in-pavement white lights located at specified hold-short points.
HOLD-SHORT POSITION SIGNS- Red and white holding position signs located alongside the hold-short point.
HOMING- Flight toward a NAVAID, without correcting for wind, by adjusting the aircraft heading to maintain a relative bearing of zero degrees.
HOVER CHECK- Used to describe when a helicopter/VTOL aircraft requires a stabilized hover to conduct a performance/power check prior to hover taxi, air taxi, or takeoff. Altitude of the hover will vary based on the purpose of the check.
HOVER TAXI- Used to describe a helicopter/VTOL aircraft movement conducted above the surface and in ground effect at airspeeds less than approximately 20 knots. The actual height may vary, and some helicopters may require hover taxi above 25 feet AGL to reduce ground effect turbulence or provide clearance for cargo slingloads.
HZ- (See HERTZ.)