TQ Engine Torque
TR Tail Rotor
TRA Tail Rotor Actuator
TRANS Transmission
TRDS Tail Rotor Drive System
TRSOV Tail Rotor Shut-Off Valve
TU Transition Up
UCPL Uncoupled
UHF Ultra High Frequency
ULB Underwater Locator Beacon
UNLK Unlock
UTC Universal Time Coordinates
UTIL Utility
UTIL SOV Utility Shut-Off Valve
UV Ultra-Violet
VAPP VOR Approach
VCE Voice
VLO Maximum landing gear operating speed
VLE Maximum landing gear extended speed
VNE Never Exceed speed
VDR VHF Data Radio
VEL Velocity
VENT Ventilation
VFR Visual Flight Rules
VGP Vertical Glide Path
VHF Very High Frequency
VIDL VOR/ILS Data Link
VIL Vertical Integrity Limit (GPS)
VIP Very Important Person
V/L VOR/LOC
VNAV Vertical Navigation
VOL Volume
VOR VHF Omnidirectional Range
VOX Voice Operated Switch / Voice Operated Circuit
VPATH Vertical Flight Path
vs versus
VS Vertical Speed
VTA Vertical Track Alert
V/UHF VHF and UHF
WHL Wheel
WL Water Line
WOW Weight-On-Wheels
WT Weight
WTR Winch-man Trim
WX Weather
WXR Weather Radar
XFD Crossfeed
XFEED Crossfeed
XMIT Transmit
XMSN Transmission