Editing NOTAR (section)

{{Short description|Alternative helicopter tail system with no external tail rotor.}}
[[File:G-HAAT (35321548351).jpg|thumb|upright=1.14|MD Explorer air ambulance]]

'''NOTAR''' ("no tail rotor") is a [[helicopter]] system which avoids the use of a [[tail rotor]]. It was developed by [[MD Helicopters|McDonnell Douglas Helicopter Systems]] (through their acquisition of [[Hughes Helicopters]]). The system uses a fan inside the tail boom to build a high volume of low-pressure air, which exits through two slots and creates a [[boundary layer]] flow of air along the tailboom utilizing the [[Coandă effect]]. The boundary layer changes the direction of airflow around the tailboom, creating thrust opposite the motion imparted to the [[fuselage]] by the torque effect of the main rotor. Directional yaw control is gained through a vented, rotating drum at the end of the tailboom, called the direct jet thruster. Advocates of NOTAR assert that the system offers quieter and safer operation than a traditional tail rotor.<ref name="kulikovair">{{cite web |title=NOTAR Helicopter Design |date=7 January 2000 |publisher=Kulikov Aircraft Design |url=http://www.kulikovair.com/Notar.htm |url-status=usurped |archive-url=https://archive.today/20000527162120/http://www.kulikovair.com/Notar.htm |archive-date=27 May 2000}}</ref>