Definition
A defined volume of airspace surrounding a space launch or reentry vehicle's nominal flight path, established to contain the hazards associated with a vehicle transitioning between the surface and on-orbit operations. The THA is active during the transitional phase of a launch or reentry and is published or issued via NOTAM so that other aircraft remain clear.
Plain English
A block of airspace set aside around a rocket or returning spacecraft while it climbs out or comes back down, kept clear of regular air traffic because of the risk it poses during that phase.
Context Anchor
You may see THA in airspace notices or planning information connected with commercial space launches and reentries.
Derivation
"Transitional" comes from Latin transire, "to go across" — the vehicle is going across between the surface and orbit. "Hazard Area" simply names what it is: a region marked off because of risk. The name tells you both when it matters (during the transition) and why (hazard).
Why Pilots Care
Aircraft entering an active THA risk collision with debris, encountering blast effects, or losing separation from objects moving unpredictably between phases.
Grounding Statement
Think of a THA as temporary protected airspace for a moving risk during a space operation.
Intuition Check
Do not read hazard area as any place that seems dangerous. In this FAA use, a THA is a specific, planned airspace area tied to a launch or reentry operation.
Example Sentence 1
During preflight, the briefer pointed out a THA active that afternoon along the coast for a scheduled launch, so we filed a route well inland.
Example Sentence 2
Preflight planning included confirming the THA activation times so the flight could maintain safe distance from the launch transition corridor.