O - Aviation Glossary
- Obstacle
- Obstacle Departure Procedure (ODP)
- Obstacle departure procedures (ODP)
- Obstacle Free Zone
- Obstruction
- Obstruction Light
- Obstruction lights
- Occluded front
- Oceanic Airspace
- Oceanic Error Report
- Oceanic Published Route
- Oceanic Transition Route (OTR)
- OEI
- Off Course
- Off-Route Obstruction Clearance Altitude (OROCA)
- Off-Route Vector
- Offset Parallel Runways
- Offshore/Control Airspace Area
- OM
- Omission error
- On Course
- On-Course Indication
- On-demand operation
- One-Minute Weather
- Onserviceable (U/S)
- Operate
- Operational
- Operational control
- Operations Over People (OOP)
- Operations Specifications (OPSPECS) [ICAO]
- Operator - Unmanned Aircraft System (UAS)
- Opposite Direction Aircraft
- OPSPECS
- Option Approach
- Organized Track System (OTS)
- Orientation
- Otolith organ
- OUT
- Out Of Service/Unserviceable (U/S)
- Outer Area
- Outer Compass Locator
- Outer Fix
- Outer Fix Arc
- Outer Fix Time (OFT)
- Outer Marker (OM)
- Outside air temperature (OAT)
- OVER
- Over-the-top
- Overcontrolling
- Overhead Maneuver
- Overlying Center
- Overpower
- Overseas air commerce
- Overseas air transportation