TM 1-1520-240-10            B-3 ABBREVIATION TERM ID or IDENT Identification . . . . . . IFF Identify Friend or Foe . . . . . . . . . IFR Instrument Flight Regulations . . . . . . . . . IGE In Ground Effect . . . . . . . . . IGN Ignition . . . . . . . . . ILCA Integrated Lower Control Actuator . . . . . . . . ILS Instrument Landing System . . . . . . . . . IMC Instrument Meteorological Condi . . . . . . . . . tions IN. or “ Increase . . . . . . INC Increase . . . . . . . . . IND Indicator . . . . . . . . . INOP Inoperative . . . . . . . . INST Instruments . . . . . . . . INT or INPH Interphone . . . . . . . . INTR Interior . . . . . . . . ITO Instrument Takeoff . . . . . . . . . JP-4, JP-5 or JP-8 Jet Petroleum . . . . . . K Key . . . . . . . . . . . KYBD Keyboard . . . . . . . kHz Kilohertz . . . . . . . . . KIAS Knots Indicated Airspeed . . . . . . . . Km Kilometer . . . . . . . . . KN or KTS Knots . . . L Left . . . . . . . . . . . LAT/LONG Latitude/Longitude . . . LB Pounds(s) . . . . . . . . . . LB-FT Pound-Feet (Torque) . . . . . . . LB/GAL Pounds per Gallon . . . . . LB/HR Pounds per Hour . . . . . . . LBL Left Butt Line . . . . . . . . . LCT Longitudinal Cyclic Trim . . . . . . . . . LD Load . . . . . . . . . . DL-V Load Variable . . . . . . . . LF Low Frequency . . . . . . . . . . LG Length . . . . . . . . . . LH Left-Hand . . . . . . . . . . LO Low . . . . . . . . . . LOC Location . . . . . . . . LSB Lower Sideband . . . . . . . . . LTG Lighting . . . . . . . . . LTS Lights . . . . . . . . . LVL Level . . . . . . . . . M Mode or Middle . . . . . . . . . . . ABBREVIATION TERM MA Missile Alert . . . . . . . . . MAG Magnetic . . . . . . . . MAL Malfunction . . . . . . . . MAM Manual . . . . . . . . MAX Maximum . . . . . . . . MB or MKR BCN Marker Beacon . . . M-C Mode C . . . . . . . . . MCW Modulated Carrier Wave . . . . . . . MDL Module . . . . . . . . MED Medium . . . . . . . . MEM Memory . . . . . . . . MEM LOAD Memory Load . . . . . . . MHz Megahertz . . . . . . . . MID Middle . . . . . . . . . MIL Angular Measurement, Military . . . . . . . . . MIN Minute(s) or Minimum . . . . . . . . . MK Manual keying . . . . . . . . . MM Millimeter . . . . . . . . . MOM Momentary or Moment . . . . . . . MOM. ON Momentary On . . . MSG Message . . . . . . . . MSL Mean Sea Level or Missile . . . . . . . . MST Master Caution . . . . . . . . MTR Motor . . . . . . . . MWOD Multiple Word of Day . . . . . . N North . . . . . . . . . . . NAC Nacelle . . . . . . . . NAV Navigation . . . . . . . . NB Narrow Band . . . . . . . . . . NM Nautical Mile . . . . . . . . . NO Number . . . . . . . . . NORM Normal . . . . . . NPU Navigation Processor Unit . . . . . . . . NVG Night Vision Goggles . . . . . . . . N1 Gas Producer (Speed) . . . . . . . . . . N2 Power Turbine (Speed) . . . . . . . . . . O Outer . . . . . . . . . . . OBS Obstacle . . . . . . . . OFST Offset . . . . . . . OGE Out-of-Ground Effect . . . . . . . . ONS Omega Navigation System . . . . . . . . OP Operation . . . . . . . . . . OU Optical Unit . . . . . . . . . OUTB’D Outboard . . . . .