JAMMING- Electronic or mechanical interference which may disrupt the display of aircraft on radar or the transmission/reception of radio communications/navigation.

JET BLAST- Jet engine exhaust (thrust stream turbulence).

(See WAKE TURBULENCE.)

JET ROUTE- A route designed to serve aircraft operations from 18,000 feet MSL up to and including flight level 450. The routes are referred to as "J" routes with numbering to identify the designated route; e.g., J105.

(See Class A AIRSPACE.)

JET STREAM- A migrating stream of high-speed winds present at high altitudes.

JETTISONING OF EXTERNAL STORES- Airborne release of external stores; e.g., tiptanks, ordnance.