The article examines and describes in detail the sphere of small aircraft. It differs from other types of aviation in that it includes relatively small aircraft: planes with a takeoff weight of up to 8600 kg of power. with a capacity of up to 19 passengers; helicopters with a takeoff weight of up to 4500 kg of power; drones with a takeoff weight of up to 8600 kg. During Soviet times. https://www.roneverhart.com/Modern-Rectangular-Keyed-Entry-Pocket-Door-Emtek-2113/