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 MATERIALS (HAZMAT)- Hazardous materials as defined by 49 Code of Federal Regulations ­(CFR) §171.8.
(Refer to 49 CFR part 171.8)
(Refer to AIM)

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), graphical airmen's meteorological information (G-AIRMET) 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.

HAZMAT-

(See HAZARDOUS MATERIALS.)

HEAVY (AIRCRAFT)-

(See AIRCRAFT CLASSES.)

HEIGHT ABOVE AIRPORT (HAA)- The height of the Minimum Descent Altitude above the published airport ­elevation. This is published in conjunction with circling minimums.

(See MINIMUM DESCENT ALTITUDE.)

HEIGHT ABOVE LANDING (HAL)- The height above a designated helicopter landing area used for helicopter ­instrument approach procedures.

(Refer to 14CFR part97.)

HEIGHT ABOVE TOUCHDOWN (HAT)- The height of the Decision Height or Minimum Descent Altitude ­above the highest runway elevation in the touchdown zone (first 3,000 feet of the runway). HAT is published ­on instrument approach charts in conjunction with all straight‐in minimums.

(See DECISION HEIGHT.)

(See MINIMUM DESCENT ALTITUDE.)

HELICOPTER- A rotorcraft that, for its horizontal motion, depends principally on its engine‐driven rotors.

(See ROTORCRAFT.)

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 30MHz.

(See HIGH FREQUENCY COMMUNICATIONS.)

HIGH FREQUENCY COMMUNICATIONS- High radio frequencies (HF) between 3 and 30MHz used for ­air‐to‐ground voice communication in overseas operations.

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.)

HIGH UPDATE RATE SURVEILLANCE– A surveillance system that provides a sensor update rate of less than ­4.8 seconds.

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.

(See ICAO term HOLDING POINT.)

HOLD‐IN‐LIEU OF PROCEDURE TURN- A hold‐in‐lieu of procedure turn must be established over a final ­or intermediate fix when an approach can be made from a properly aligned holding pattern. The hold‐in‐lieu of ­procedure turn permits the pilot to align with the final or intermediate segment of the approach and/or descend ­in the holding pattern to an altitude that will permit a normal descent to the final approach fix altitude. The ­hold‐in‐lieu of procedure turn is a required maneuver (the same as a procedure turn) unless the aircraft is being ­radar vectored to the final approach course, when “NoPT” is shown on the approach chart, or when the pilot ­requests or the controller advises the pilot to make a “straight‐in” approach.

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.

(See HOLDING FIX.)

(Refer to AIM.)

HOLDING FIX- A specified fix identifiable to a pilot by NAVAIDs or visual reference to the ground used as ­a reference point in establishing and maintaining the position of an aircraft while holding.

(See FIX.)

(See VISUAL HOLDING.)

(Refer to AIM.)

HOLDING POINT [ICAO]- A specified location, identified by visual or other means, in the vicinity of which ­the position of an aircraft in flight is maintained in accordance with air traffic control clearances.

HOLDING PROCEDURE-

(See HOLD PROCEDURE.)

HOLD‐SHORT POINT- A point on the runway beyond which a landing aircraft with a LAHSO clearance is ­not authorized to proceed. This point may be located prior to an intersecting runway, taxiway, predetermined ­point, or approach/departure flight path.

HOLD‐SHORT POSITION LIGHTS- Flashing in‐pavement white lights located at specified hold‐short points.

HOLD‐SHORT POSITION MARKING- The painted runway marking located at the hold‐short point on all ­LAHSO runways.

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.

(See BEARING.)

(See ICAO term HOMING.)

HOMING [ICAO]- The procedure of using the direction‐finding equipment of one radio station with the ­emission of another radio station, where at least one of the stations is mobile, and whereby the mobile station ­proceeds continuously towards the other station.

HOT SPOT- A location on an airport movement area with a history of potential risk of collision or runway ­incursion, and where heightened attention by pilots/drivers is necessary.

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.

(See AIR TAXI.)

(See HOVER CHECK.)

(Refer to AIM.)

HOW DO YOU HEAR ME?- A question relating to the quality of the transmission or to determine how well ­the transmission is being received.

HZ-

(See HERTZ.)