NOTAR® Technology

The NOTAR® anti-torque system eliminates all of the mechanical disadvantages of a tail rotor, including long drive shafts, hanger bearings, intermediate gearboxes and ninety-degree gearboxes. Using the natural characteristics of helicopter aerodynamics, the NOTAR system provides safe, quiet, responsive, FOD-resistant directional control.

How does it work?

The enclosed variable-pitch composite blade fan produces a low pressure, high volume of ambient air to pressurize the composite tailboom. 

The air is expelled through two slots which run the length of the tailboom on the starboard (right) side, causing a boundary-layer control called the Coanda Effect. The result is that the tailboom becomes a "wing", flying in the downwash of the rotor system, producing up to 60 percent of the anti-torque required in a hover. The balance of the directional control is accomplished by a rotating direct jet thruster. 

In forward flight, the vertical stabilizers provide the majority of the anti-torque, however directional control remains a function of the direct jet thruster. 

NOTAR® Technology Delivers:

In Production

There are just two production helicopters that utilize the NOTAR system, both produced by MD Helicopters.

Models - 2 Models

  • MD 520N

    MD 520N Quiet and Safe. Fast and Potent.

    Estimated Performance Capabilities
    Max Gross Weight: Int
    3,350 lb
    Max Gross Weight: Ext
    3,850 lb
    Useful Load
    1,764 lb
    Hover-In Ground Effect
    9,300 ft
    Hover-Out Ground Effect
    5,600 ft
    Max Cruise Speed
    123 kt
    Max Operating Altitude
    20,000 ft
    210 nm
    MD 520N Details
  • MD 902 Explorer

    MD 902 Explorer High Performance. High Technology. Higher Standards.

    Estimated Performance Capabilities
    Max Gross Weight: Int
    6,500 lb
    Max Gross Weight: Ext
    6,900 lb
    Useful Load
    3,125 lb
    Hover-In Ground Effect
    10,650 ft
    Hover-Out Ground Effect
    8,780 ft
    Maximum Cruise Speed
    131 kt
    Max Rate of Climb
    2120ft / min
    328 nm
    MD 902 Details
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