U - Aviation Glossary
- Ultimate load factor
- Ultra-high frequency (UHF)
- Ultrahigh Frequency (UHF)
- Ultralight Vehicle
- UNABLE
- Unassociated
- Uncaging
- Uncontrolled Airspace
- Under The Hood
- Underpower
- Unfrozen
- UNICOM
- United States
- United States air carrier
- United States Terminal Procedures Publication (TPP)
- Unmanned Aircraft (UA)
- Unmanned Aircraft System (UAS)
- Unpublished Route
- Unreliable (GPS/WAAS)
- Unusual attitude
- Upwind Leg
- Urgency
- Urgency [ICAO]
- Useful load
- User-defined waypoints