Monoplane: A form of airplane which has but one main supporting surface extending equally on each side of the body.

Mooring band: The band of tape over the top of a balloon to which are attached the mooring ropes.

Nacelle: The inclosed shelter for passengers or for an engine. Usually in the case of a single-engine pusher it is the central structure to which the wings and landing gear are attached.

Net: A rigging made of ropes and twine on spherical balloons which supports the entire load carried.

Ornithopter: A form of aircraft deriving its support and propelling force from flapping wings.

Overhang: One-half the difference in the span of the upper and lower planes of a biplane.

Pancake: To “level off” an airplane, just before landing, at too great an altitude, thus stalling it and causing it to descend with the wings at a very large angle of incidence.

Panel: The unit piece of fabric of which the envelope is made.

Parachute: An apparatus, made like an umbrella, used to retard the descent of a falling body.

Patch system: A system of construction in which patches (or adhesive flaps) are used in place of the suspension band.