4/20/23 

Pilot/Controller Glossary 

H 

HAA

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(See HEIGHT ABOVE AIRPORT.) 

HAL

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(See HEIGHT ABOVE LANDING.) 

HANDOFF

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 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

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(See HEIGHT ABOVE TOUCHDOWN.) 

HAVE NUMBERS

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Used by pilots to inform ATC that they have received runway, wind, and altimeter 

information only. 
HAZARDOUS MATERIALS (HAZMAT)

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 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

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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

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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

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(See HAZARDOUS MATERIALS.) 

HEAVY (AIRCRAFT)

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(See AIRCRAFT CLASSES.) 

HEIGHT ABOVE AIRPORT (HAA)

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 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)

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 The height above a designated helicopter landing area used for helicopter 

instrument approach procedures. 

(Refer to 14 CFR Part 97.) 

HEIGHT ABOVE TOUCHDOWN (HAT)

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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

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 A heavier-than-air aircraft supported in flight chiefly by the reactions of the air on one or more 

power-driven rotors on substantially vertical axes. 
HELIPAD

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 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. 

PCG H

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