25 ft. 6 in.
9 ft. 10 in.
27 ft. 3 in.
The NOTAR Helicopter, produced by McDonnell Douglas (now Boeing), does away with the long drive shaft, bearings, and angled gearbox of a tail rotor and replaces them with a fan inside the tail boom. Air from the fan comes out through two slots running all along the tail boom on its right side. The high volume, low pressure air works in conjunction with the rotor downwash to provide over half of the helicopter's directional thrust, keeping it moving in a straight line. A moving nozzle in the rear of the tail boom provides the remainder of the torque control, plus full directional control. The "NOTAR" name, copyrighted by the manufacturer, stands for no tail rotor.
The NOTAR Helicopter MD520N, shown on this page, is probably best known for its lack of a tail rotor that results in its being among the world's quietest production helicopters. It is a turbine powered, five blade rotor, light helicopter that provides zippy operation. It is used by the police for observation, crowd handling, search and rescue. and as a medical transport by hospitals. The helicopter has also been used by various wildlife operations for surveying, look out, rules enforcement, and blaze fighting.
Thanks to ample glass around the cockpit, the crew of the NOTAR Helicopter can see well in all forward directions around the aircraft. Law enforcement models have a searchlight mounted under the mid fuselage as standard equipment. Some are even equipped with a cable cutter under the cockpit for added safety while flying at rooftop levels. The helicopter comes equipped with skids, but wheels and pontoons can be added for better ground handling or water landings.
A total of some 350 NOTAR helicopters have been produced to date.