Scale: 1:24
Length: 15"
Span: 14"

The Hughes MD 520N was the world's first production model Helicopter whose yaw control system is based on an air outlet at the tail instead of a tail rotor. The NOTAR? (no tail rotor) concept, using compressed air to offset torque instead of a conventional tail rotor, was pioneered in the MD-520N. A NOTAR version of the heavy-lift Model 530 became the MD-530N. McDonnell Douglas pioneered the concept of a system called NOTAR (for NO TAil Rotor) which eliminates the dangerous and complex tail rotor system used in conventional Helicopters. In the NOTAR system a variable-pitch axial fan is located at the front of the tail boom to drive air through the boom. There it exhausts through slots along the boom to produce a Coanda effect which produces torque to counteract that caused by the Helicopter's main rotor. The NOTAR system simplifies Helicopter tail assemblies thereby improving reliability and reducing maintenance requirements. Pilot loading reduces because the pilot does not have to account for tail rotor inertial effects.