U

U
U/FLOOR	Underfloor
U/S	Unserviceable
UAC	Upper Area Control Centre
UADF	User Application Definition File
UART	Universal Asynchronous Receiver Transmitter
UD	Document Unit ("UnitÙ Documentaire")
UD	Upper Deck
UDC	Upper Deck Cargo
UDCC	Upper Deck Cargo Compartment
UDCD	Upper Deck Cargo Door
UDL	Unit Detail Listing
UDP	User Datagram Protocol
UEB	Underseat Electronic Box
UER	Unplanned Engine Removal
UERF	Uncontained Engine Rotor Failure
UF	Underfrequency
UHF	Ultra High Frequency
UICDL	User Interface Configuration Download List
ULA M	Universal Light Adapter Module
ULA	Universal Light Adapter
ULB	Underwater Locator Beacon
ULD	Unit Load Device
ULLI	Understep LED Light
UMS	User Modifiable Software
UMTS	Universal Mobile Telecommunications System
UNBAL	Unbalance, Unbalanced
UNCPLG	Uncoupling
UNCRCTD	Uncorrected
UND	Under
UNDERPRESS	Underpressure
UNIV	Universal
UNLK	Unlock
UNLKD	Unlocked, Unlocking
UNSD	Unused
UPLK	Uplock
UPLKD	Uplocked
UPPR	Upper
UPR	Upper
UR	Utilization Rate
US	Ultrasonic
US	Under Speed
US	United States
USB	Universal Serial Bus
USB	Upper Sideband
UTA	Upper Control Area
UTC	Universal Time Coordinated
UUT	Unit Under Test
UV	Ultra-Violet
UV	Under Voltage
UVEROM	Ultra Violet Erasable Read Only Memory
UWBS	Universal Wireless Backbone System
UWY	Upper Airway