Definition
Obstacles such as towers, buildings, terrain features, or other structures that are formally identified, charted, and listed on official aeronautical publications including sectional charts, instrument approach plates, and airport diagrams.
Plain English
Things sticking up into the airspace — like radio towers, tall buildings, or hills — that have been officially recorded and printed on the maps and charts pilots use.
Context Anchor
Pilots encounter published obstacles when reviewing charts, airport information, departure planning, approach planning, and training scenarios that require checking whether the aircraft can safely clear obstacles.
Derivation
‘Published’ here means ‘printed in an official aeronautical publication.’ It does not mean ‘well-known’ or ‘announced.’ An obstacle becomes ‘published’ once it has been surveyed, accepted, and added to the charts pilots are expected to use.
Why Pilots Care
Pilots must account for published obstacles to maintain required obstacle clearance and to comply with minimum safe altitudes during all phases of flight.
Intuition Check
Do not assume “published obstacles” means every obstacle that exists. It means obstacles that are officially shown or listed for pilots to consider; there may still be unlisted obstacles in the area.
Example Sentence 1
During flight planning, the instructor had the student identify all published obstacles along the route and confirm the planned cruise altitude provided adequate clearance.
Example Sentence 2
During preflight planning the instructor asked the student to note all published obstacles within five miles of the airport.