INSTRUMENT FLIGHT RULES (IFR) Rules governing the procedures for conducting instrument flight. Also a term used by pilots and controllers to indicate type of flight plan.

INTERFERENCE DRAG Type of drag produced by placing two objects adjacent to one another. Combines the effects of form drag and skin friction.

INVERSION An increase in temperature with altitude.

JUDGMENT The mental process of recognizing and analyzing all pertinent information in a particular situation, a rational evaluation of alternative actions in response to it, and a timely decision on which action to take.

KINESTHESIA The sensing of movements by feel.

KITE To pressurize and raise the wing overhead the PPC cart.

KITING Taxiing the PPC on the ground with the wing inflated and overhead.

KNOWLEDGE EXAM See FAA KNOWLEDGE EXAM.

LATERAL AXIS An imaginary line passing through the center of gravity of a PPC and extending across the PPC from one side of the aircraft to the other side.

LEADING EDGE The part of an airfoil that meets the airflow first.

LIFT One of the four main forces acting on an aircraft. On a powered parachute, an upward force created by the effect of airflow as it passes over and under the wing.

LIGHT-SPORT AIRCRAFT (LSA) An aircraft that meets the requirements defined in 14 CFR 1.1, regardless of airworthiness certification.

LINE-OVERS A dangerous situation when the suspension line goes over the top of the wing instead of going straight from the wing to the riser system. This condition will prevent proper inflation of the wing.

LINE TWISTS When the PPC suspension lines on both sides of the wing are spiraled together. Flying with a line twist is unsafe; the wing is unairworthy until it is corrected.

LOC A preflight check: L – Lines Free, O – Cells Open, C – Wing Centered.

LOGBOOK A record of activities: flight, instruction, inspection and maintenance. Reference 14 CFR 43, 14 CFR 61.51, and 14 CFR 91.417.

LONGITUDINAL AXIS An imaginary line through an aircraft from nose to tail, passing through its center of gravity. The longitudinal axis is also called the roll axis of the aircraft.