Definition
TRANSITIONAL HAZARD AREA (THA)
Used by ATC. Airspace normally associated with an Aircraft Hazard Area within which the flight of aircraft is subject to restrictions.
- See: AIRCRAFT HAZARD AREA
- See: CONTINGENCY HAZARD AREA
- See: REFINED HAZARD AREA
Source: FAA Pilot/Controller Glossary (verbatim from the Federal Aviation Regulations).