The MD Helicopters MD Explorer is a light twin-engined utility helicopter designed and initially produced by the American rotorcraft specialist McDonnell Douglas Helicopter Systems.
A key feature of the MD Explorer is the NOTAR anti-torque system; instead of a traditional tail rotor, a fan exhaust is directed out of slots in the tail boom, thus using the Coandă effect for yaw control.
The benefits of NOTAR have reportedly included reduced pilot workload, greatly minimised external noise levels, and significant improvements in safety, particularly when operating in confined areas and from offshore platforms, along with general performance and controllability enhancements.