Index   A » Z          
U Uniform (ICAO)
U Upward (tendency in RVR during pervious 10 minutes)
U/L Upper / Lower Upper Link
U/S Unserviceable (AIP)
UAB Until Advised By (AIP)
UAC Upper Area Control (EuroControl)
UACC Upper Airspace Control Centre
UAP User Application Profile (RMCDE)
UAR Upper Air Route (EATM)
UAS Unmanned Aircraft System (AIP)
UASS Unofficial Airbus Study Site (Airbus Acronyms)
UAV Unmanned Aerial Vehicle (AIP)
UBAG Unaccompanied baggage (CRM)
UBL Unspecified Bit Rate (EATM)
UCDU Universal Control and Display Unit (EATM)
UCM ULD Control message (CRM AHM388)
UCRC Under Crew Rest Container or MCR or LDMCR
UD IATA/FIATA/UFTAA delegate discount
UD Upper Deck (Airbus)
UDA Upper Advisory (Service) Area (EATM)
UDC Compute UDRE Range Difference (FAA)
UDF Ultra High Frequency Direction Finding (AIP)
UDF Unducted Fan
UDRE User Differential Range Error (EATM)
UEATMS Uniform European Air Traffic Management System (EATM)
UEB Underseat Electronic Box (Airbus)
UEO Union de l'Europe Occidentale (fr.) / Western European Union WEU
UERE User Equivalent Range Error (EATM)
UFD Unit Fault Data (Airbus Acronyms)
UFF Ultimate Fallback Facility (EATM)
UFIR Upper Flight Information Region (FAA)
UFN Until Further Notice (AIP)
UFO Unidentified Flying Object
UFPF United Flight Planning and Filing (NG FAA)
UFR Upper Flight Region (EATM)
UFTAA United Federation of Travel Agents Associations (IATA)
UHDT Unable Higher Due Traffic
UHF Ultra High Frequency . . .300 to 3000 MHz (AIP)
UI User Interface (EATM)
UIC Upper Information Centre (AIP)
UIC Unit Identity Code (EATM)
UIECS Union of International and European Civil Servants
UIMS User Interface Management System (EATM)
UIR Upper (flight) Information Region
UIVE User Ionospheric Vertical Range (EATM)
UKAATS UK Advanced ATS
UL Ultra Light glider
UL Upper Limit (AIP)
UL Upper Link (ATS route indication) or Uplink (EATM)
ULB Underwater Locator Beacon (Airbus Acronyms)
ULD Unit Load Device (CRM) *
ULDP ULD Panel (IATA CSC)
ULDR ULD Regulations (IATA)
ULM Ultra Light Motorized
ULR Ultra Long Range (AIP)
ULV Unit Load Version (CLS)
UM Unaccompanied Minor (PHM)
UMA Unmanned Aircraft (EATM)
UMNR Unaccompanied Minor (PNR PHM)
UN Unable flight status-does not operate (CRM)
UNA Unable (AIP)
UNAP Unable to Approve (AIP)
UNAVBL Unavailable
UNINC Unusual Incidents (EATM)
UNK Unknown
UNL Unlimited (AIP)
UNLK Unlock (Airbus Acronyms)
UNLGT Unlighted
UNMKD Unmarked
UNMNT Unmonitored
UNREL Unreliable (AIP)
UNT Until
UNUSBL Unusable
UPD Update Plan Divergence
UPGR Planned operational upgrading to higher C/cl . . . i.e. on overbooked flights in Y/cl (PHM)
UPPR Upper (Airbus) . . . UPR
UPR Upper (MET)
UPS Uninterrupted Power Supply / System
UPS United Parcel Service
UPSEL Update Selection (EATM)
URA User Range Accuracy (EATM)
URANIA UpRading Athens Terminal Area and  Interfacing to the PALLAS ACC system
URB CFMU – User Relations Bureau
URD User Requirements Document
URE User Range Error (EATM)
URET User Request Evaluation Tool (MITRE Conflict Detection product)
URG Urgency (ICAO)
URP User Requirements Phase
URTF User Requirements Task Force
USART Universal Synchronous / Asynchronous Receiver/Transmitter (EATM)
USD US Dollar
US DOT US Department of Transportation
USG US Government
USNO US Naval Observatory
UTA Upper Control Area (ICAO)
UTA Upper Transition Area
UTC Universal Coordinated Time
UTM ULD Technical Manual . . . replaced by IATA ULDR
UTP Unshielded Twisted Pair
UU Unable (CRM)
UUP Updated (Airspace) Use Plan
UUT Unit Under Test (FAA)
UVA Utility Value Analysis
UWBS Universal Wireless Backbone System (Airbus)
UWS Unit Load Device/Bulk Load Weight Signal (AHM 581)