Definition
Fixed objects or surface conditions on or near an airport that can interfere with the safe movement of an aircraft on the ground or during the early takeoff and final landing phases. Examples include towers, antennas, signs, lighting structures, parked aircraft, vehicles, fences, snow banks, construction equipment, and uneven or soft surfaces.
Plain English
Things on the ground at or around an airport that a pilot could hit, snag a wingtip on, or run into while taxiing, taking off, or landing.
Context Anchor
Seen during preflight planning, airport briefings, taxi planning, takeoff and landing discussions, and scenario-based training exercises.
Derivation
“Obstruction” comes from an older word meaning “to block.” “Hazard” means a source of danger. Together, the phrase points to ground-level things that can block, damage, or endanger an aircraft.
Why Pilots Care
Overlooking these features during planning or flight can result in controlled flight into terrain or obstacle strikes, both major contributors to preventable accidents.
Intuition Check
Do not assume “ground-based” means only objects sitting on the runway. It also includes anything on the surface, or rising from it, that could affect the aircraft when it is close to the ground.
Example Sentence 1
During the taxi briefing, the instructor pointed out several ground-based obstructions along the route, including construction barriers near the south ramp.
Example Sentence 2
During the low-level navigation exercise the instructor reminded the pilot to maintain extra altitude to clear any ground-based obstructions/hazards along the route.