Aero-Terms!

Aero-Terms are designed to be a daily reminder of the terms, names, acronyms and explanations of the unique language that populates the aviation world. Aerospace, sport aviation, fixed wing, helo, you name it... it's all fair game.

Aero-Terms should serve as a quick but intriguing reminder of the terms you may use every day, or an introduction to an aspects of the Aero-World you may not yet be familiar with. ANN also encourages readers to go beyond the FMI link, and further research any intriguing terms.

Suggestions for future Aero-Terms are ALWAYS welcome, as are additions or discussion of the explanations given for each Aero-Term.

Prominent Obstacle

An obstacle that meets one or more of the following conditions:

1. An obstacle which stands out beyond the adjacent surface of surrounding terrain and immediately projects a noticeable hazard to aircraft in flight.
2. An obstacle, not characterized as low and close in, whose height is no less than 300 feet above the departure end of takeoff runway (DER) elevation, is within 10NM from the DER, and that penetrates that airport/heliport’s diverse departure obstacle clearance surface (OCS).
3. An obstacle beyond 10NM from an airport/heliport that requires an obstacle departure procedure (ODP) to ensure obstacle avoidance.

FMI: www.faa.gov