Definition
An obstacle that meets one or more of the following conditions: the obstacle is considered to be a navigational hazard within the safety area of the airport; the obstacle penetrates an imaginary surface as described in 14 CFR Part 77; the obstacle is depicted on a published instrument procedure chart; or the obstacle is otherwise determined to be a hazard to navigation by the airport authority or FAA.
Plain English
An obstacle that stands out enough — by height, location, or risk — that pilots and controllers need to know about it. It is significant enough to be charted, called out, or treated as a hazard during ground or flight operations.
Context Anchor
You may see this term in chart legends, airport information, route planning, and procedure notes where obstacles near a flight path matter.
Derivation
From Latin prominere, 'to jut out or stand forward.' A prominent obstacle is one that 'stands out' from its surroundings enough to matter — not just any obstruction, but one that draws attention because of its position or hazard potential.
Why Pilots Care
Pilots use these to plan safe altitudes and routes; missing one increases collision risk during visual navigation or in marginal weather.
Grounding Statement
If a tall tower or ridge near your route would be hard to ignore and important to avoid, it may be treated as a prominent obstacle.
Intuition Check
Do not read “prominent” as just “famous” or “easy to see.” In this context, it means the obstacle is significant to aviation because pilots may need to notice it, avoid it, or use it as a reference.
Example Sentence 1
The controller advised the pilot of a prominent obstacle — a crane — off the departure end of runway 27.
Example Sentence 2
We climbed an extra 500 feet to ensure clearance over the prominent obstacle shown near the highway.