Greatly reduced noise and vibration due to the enclosure of the blade tips and greater number of blades. A decrease in power requirements during the cruise phase of flight. Typically lighter and smaller than conventional counterparts. A lower susceptibility to foreign object damage because the enclosure makes it less likely to suck in loose objects such as small rocks. Enhanced anti-torque control efficiency and reduction in pilot workload. Reduced chance for the tail rotor to cause accidents, because it cannot strike the environment. Disadvantages The Fenestron's disadvantages are those common to all ducted fans when compared to propellers. They include: Greater weight, power requirement, and air resistance brought by the enclosure; Higher construction and purchasing cost. Increase in power required during the hover phase of flight. See also NOTAR References Notes Citations Bibliography Corda, Stephen. Introduction to Aerospace Engineering with a Flight Test Perspective. John Wiley & Sons, 2017. . Gay, Daniel. Composite Materials: Design and Applications. CRC Press, 2014. . Johnson, Wayne. "Rotorcraft Aeromechanics." Cambridge University Press, 2013. . Leishman, Gordon L. "Principles of Helicopter Aerodynamics." Cambridge University Press, 2006. . Newman, Ron. The Technical, Aerodynamic & Performance Aspects of a Helicopter. BookBaby, 2015. . Prouty, Ray. Helicopter Aerodynamics Volume I. Lulu.com, 2009. . External links Dave's All the World Fenestrons Helicopter components Ventilation fans