JAA Joint Aviation Authorities.
JAR Joint Aviation Requirements, agreed by all major EC countries (JAR 25 equivalent to FAR Pt 25).
JAR-VLA JAR classification for Very Light Aircraft (MTOW limit of 750 kg; 1 653 Ib).
JASDF Japan Air Self-Defence Force.
JASSM Joint Air-to-Surface Stand-off Missile (US designation = AGM-158).
JATO Jet-assisted take-off (actually means rocket-assisted).
JCAB Japan Civil Airworthiness Board.
JDA Japan Defence Agency.
JDAM Joint Direct Attack Munition, being a GPS-duidane package added to existing bomb bodies, US designations being GBU-29 (with Mk 81 bomb), GBU-30 (Mk 82), GBU-31 (Mk 83), GBU-32 (Mk 84 or BLU-109/B) and GBU-35 (BLU-110/B).
JGSDF Japan Ground Self-Defence Force.
JMSA Japan Maritime Safety Agency.
JMSDF Japan Maritime Self-Defence Force.
joined wing Tandem wing layout in which forward and aft wings are swept so that the outer sections meet.
JPATS Joint Primary Aircraft Training System (Beech T-6A Texan ll).
JSC Joint stock company.
JSF Joint Strike Fighter. (The Lockheed Martin F-35).
JSOW Joint Stand-Off Weapon, US designations being AGM-154A (with 145 BLU-97/B bomblets), AGM-154B (with six BLU-108/B bomblets) and AGM-154C (with BROACH penetrating warhead).
J-STARS US Air Force/Navy Joint Surveillance and Target Attack Radar System in Northrop Grumman E-8C.
JTIDS Joint Tactical Information Distribution System (NATO Link 16).
Junkers aileron Control surface (sometimes flaperon) suspended from mountings to the rear of wing trailing edge.
JVX Joint Vertical experimental – the tiltrotor project which became the V-22 Osprey.