UART
Universal Asynchronous Receiver Transmitter
UATP
Universal Air Travel Plan
UAV
Unmanned Air Vehicle
UFTAA
Universal Federation of Travel Agents' Associations
UHF
Ultra High Frequency
UHF
Ultra-High Frequency
UIR
Upper Information Region
ULB
Underwater Locator Beacon
USB
Universal Serial Bus
UTC
Universal Time Coordinate
UTC
Universal Coordinated Time