ITO  Indium-Tin Oxide 
ITS  Integrated Test System 
ITT  (1) Interstage Turbine Temperature 
(2) Inter-Turbine Temperature 
ITU  International Telecommunications Union 
IV  Isolation Valve 
ITWS  Integrated Terminal Weather System 
J 
JAA  European Joint Airworthiness Authority 
JAL  Japan Air Lines 
JAR  Joint Airworthiness Requirement 
JAR-AWO  Joint Airworthiness Requirements - All Weather 
Operations 
JFET  Junction Field Effect Transistor 
JPO  Joint Program Office 
J/S  Jammer to Signal Ratio 
JTAG  Joint Test Action Group 
JTIDS  Joint Tactical Information Distribution System 
K 
KAL  Korean Air Lines 
Key  A hand-operated switching device or the act of oper-
ating such a device. 
KGLS  Kinematic GPS Landing System 
kHz  Kilohertz (1000 cycles per second) 
kb/s  Kilobits Per Second 
KBU  Keyboard Unit 
KPS  Kilobytes Per Second 

kts  Knots 
kVA  Kilovolt-ampere 
L 
L  Left 
L1  Frequency on which GPS SPS signals are transmitted,