Glossary

The abbreviations and special words that this manual and the U-2S cockpit use, from A to Z. On the other pages, an abbreviation with a dotted underline links to its entry here.

AC / DC: Alternating / direct current - the two halves of the electrical system.
ADF: Automatic Direction Finder - points to an NDB.
ADI: Attitude Director Indicator - the artificial horizon on the PFD.
ADSU: The air data unit that measures airspeed and altitude for the INS and MFDs.
AFCS: Automatic Flight Control System - the autopilot.
AGL: Above ground level.
ALN / IFA: INS ground alignment / in-flight alignment.
AMAD: Airframe Mounted Accessory Drive - the gearbox that drives the generators and the hydraulic pump, with its own oil system.
AOA: Angle of attack. Shown normalized: 1.00 = stall.
AP: Autopilot (the AP box on the PFD).
APCU: The autopilot computer of the AFCS; STAT / FAULT shows its status and, under MX, its fault codes.
AQ: Align quality. Counts down during alignment; lower is better.
ARC-210: The backup radio control panel on the left console - the simulator's COM 3.
ASARS-2: Advanced Synthetic Aperture Radar System - the radar nose (MFD RDR page).
ASU / GPU: Air-start unit / ground power unit - the ground carts.
ATS: Air Turbine Starter - spun by the ground starting cart or the emergency start system.
AVP: Avionics Processor - the computer that drives the three MFDs.
BCDU: Backup Control Display Unit.
BIT / SBIT: Built-in test / startup built-in test.
BRG / RNG: Bearing / range.
CHBDL: Common High Bandwidth Data Link (not simulated).
CNI: Communication, Navigation, Identification.
CRS: Course.
DCLT / DCO: Declutter / drift cut-out (PFD keys).
DDL2: The aircraft's data link - in the simulation the EFB datalink (telemetry sharing).
D/L: Data link transmitter position (SATCOM) on TRANS SEL; not simulated.
DP: Destination Point - a waypoint in the aircraft's own database.
DS: Direct steer - fly straight to a DP.
ECS: Environmental Control System - cockpit cooling, heating and pressurization.
EFA: Electronic Flight Aid - the MFD checklist reader.
EFB: Electronic Flight Bag - the U-2 EFB app on the MSFS tablet.
EGPS: Embedded GPS - the GPS receiver inside the INS.
EGT: Exhaust gas temperature.
EMER: Emergency: the emergency airfield file and page, the emergency squawk (7700), or an emergency bus.
ESS: Emergency Start System - one-shot hydrazine airstart.
ESS / MON: Essential / monitored electrical buses. The essential DC buses stay powered on the battery; the monitored buses only have power from a generator, the TR or ground power.
EW / EWS: Electronic warfare / electronic warfare system.
FAT: Free air temperature - the outside air temperature, from the temperature probe (SYS/PERF).
FF: Fuel flow.
FL: Flight level - altitude in hundreds of feet at 29.92 inHg.
FOB: Fuel on board. On SYS / PERF it shows how long that fuel lasts at the present fuel flow; DEST FOB is the fuel on arrival.
FPM: Flight Path Marker.
F/T, T/T, T/F, TTD, TFD: INS steering modes: from-to, to-to, to-from, to-to with distance, to-from with distance.
GMT / UTC: Zulu time.
GS / G/S: Glideslope.
Guard: The emergency frequency 121.500, and the separate guard receiver each COM radio has for it (the G on the UFCD).
H-70: The hydrazine fuel of the emergency start system.
HDG: Heading.
HF / UHF / VHF: High / ultra-high / very high frequency radio bands.
HSD: Horizontal situation display - the moving map under the HSI.
HSI: Horizontal Situation Indicator - the compass display on the lower PFD.
IAS / KIAS: Indicated airspeed / in knots.
IBIT: Initiated Built-In Test.
ICAW: Indications, Cautions, Advisories and Warnings - the MFD alert system. Every message: ICAW Message Dictionary.
IFF: Identification Friend or Foe - the transponder.
ILS / LOC: Instrument Landing System / its localizer.
INOP: Inoperative - present in the cockpit, no function in the simulator.
INS / INU: Inertial Navigation System / Unit.
ISS pump: The electric pump that refills the lift spoilers' emergency accumulator (SPOILER switch in EMER).
KT / NM: Knots / nautical miles.
LN33: The INS unit (LN33 FAULT = INS navigation failed).
LOX: Liquid oxygen.
LS key: Line-select key beside a display line.
Mark IV: The camera control panel on the right console: MASTER, MODE (also the radar's power), DRIFTSIGHT, SHUTTER VELOCITY and FRAME COUNTER for the OBC, the A-D lights and the viewsight hand control that aims the camera and moves the radar cursor. With no imaging sensor fitted a blank plate takes its place. See Mark IV Camera Panel.
MEC: Main engine control - the engine's fuel control; it cuts the fuel at 110.25 % N2 to stop an overspeed.
MFD: Multi-Function Display.
Mobile: The chase car and the pilot in it.
MSFS: Microsoft Flight Simulator 2024.
N1 / N2: Fan / core speed of the engine, percent rpm.
NDB: Non-directional beacon - the station an ADF points to.
OBC: Optical bar camera - the film camera that can fly in the Q-bay with the Standard nose (MFD CAM page).
OFLY: Overfly - fly over a DP instead of turning before it.
OND: Off / Night / Day - the MFD power knob.
ORB: Orbit count on the steering pages.
PDOP: Position dilution of precision - GPS geometry quality, lower is better.
PFD: Primary Flight Display - the main flying page of the MFD.
PME: Prime Mission Equipment - cameras, radar, sensors.
Pogo: Detachable outrigger wheel under each wing.
PRI / SEC: Primary / Secondary engine control mode.
PWR / STBY / NORM: Power / standby / normal - switch and mode legends.
Q-bay: Equipment bay behind the cockpit. It can carry the OBC camera (EFB Aircraft tab).
ROZ: Restricted Operating Zone - a circular zone drawn on the map.
RPLAN: Replan - the MFD route-planning page.
RT: On the BCDU: the RT page shown while the AVP runs. On the ARC-210: receiver-transmitter (RT1 = COM 1, RT2 = COM 2).
SATCOM: Satellite communication radio (not simulated).
SFD: Standby Flight Display.
SHED: ESS DC SHED - the push button with the amber SHED legend that takes the secondary essential DC loads off. See Electrical and Avionics Power.
SPAN: The satellite antenna fairing on the spine (EFB Aircraft tab).
SPOT / SRCH: The two ASARS-2 radar modes: SPOT images a small patch at high resolution, SRCH (search) covers the whole coverage area.
SSA: The ASARS-2 imagery recorder, powered by the MK IV MASTER switch.
STD: Standard altimeter setting, 29.92 inHg (1013 hPa).
Sump: The small fuselage tank that feeds the engine.
Superpods: The equipment pods on the wings: Senior Ruby (Type A), Standard (Type B) or none fitted. Senior Spear is an attachment on the left Senior Ruby pod (EFB Aircraft tab).
SYERS-2A: Senior Year Electro-optical Reconnaissance System - the camera nose (MFD CAM page).
TACAN: Military radio navigation aid giving bearing and distance.
TD: Target data - the STAT / LOAD file that fills the TP list from an INS Planner plan.
TP: Targeting point - a spot on the ground marked for the sensors, up to 10 at a time. See Targeting Points. In the U-2S manual TP means turn point, where the aircraft starts its turn before a DP; this guide writes that out.
TR: Transformer-Rectifier - makes DC from AC. On the DP pages: Turn Radius.
TRK: Ground track.
TTG / DTG: Time to go / distance to go.
UFCD: Up-Front Control Display.
UPLD: Upload - a route or airport file sent to the aircraft by the datalink (from SimBrief via the EFB).
XFER / XFMR: Transfer (fuel); XFMR is how the cross-transfer switch tooltips spell it.
XTK: Cross-track error - distance off the course line.