Fenestron
A Fenestron (sometimes alternatively referred to as a fantail or a "fan-in-fin" arrangement
The Fenestron differs from a conventional open tail rotor by being integrally housed within the tail boom, and like the conventional tail rotor it replaces, functions to counteract the
It was first developed for use on an operational rotorcraft by the French company Sud Aviation (now part of Airbus Helicopters), being first adopted upon the Aérospatiale Gazelle. Since then, the company (and its successors) have installed Fenestrons upon many of their helicopters.[2] Other manufacturers have also made limited use of the Fenestron on some of their own products, including the American aerospace corporations Bell Textron and Boeing, the Russian rotorcraft manufacturer Kamov, the Chinese Harbin Aircraft Industry Group, and the Japanese conglomerate Kawasaki Heavy Industries.
History
The concept of the Fenestron was first patented in Great Britain by the
The Fenestron was first practically applied by the French aircraft manufacturer Sud Aviation, who had decided to introduce it upon the second experimental model of their in-development SA 340 (the first prototype had been furnished with a conventional anti-torque tail rotor).[10] The SA 340's Fenestron was designed by French aerodynamicist Paul Fabre; unusually, this unit had its advancing blade set at the top in defiance of conventional practice, but this was reasoned to pose little impact upon this particular helicopter.[2][11] Fitted accordingly, on 12 April 1968, the SA 340 became the first rotorcraft to fly using a Fenestron tail unit.[5] Having been determined to have been satisfactory, this tail unit was retained and was put into production on a refined model of the rotorcraft, which was designated Aérospatiale SA 341 Gazelle.[12]
Over time, the design and performance of the Fenestron has been improved by Sud Aviation and its successor companies, as well as by other companies. During the late 1970s,
During the 1990s, a third generation Fenestron was produced by
A Fenestron is normally paired with a larger vertical stabiliser unit that also performs the role of compensating for torque; this configuration has the effect of reducing wear on the Fenestron blades and
Through multiple mergers from Sud Aviation to Airbus Helicopters, a considerable number of light, intermediate, and medium weight helicopters have used the Fenestron as an anti-torque tail rotor. Such implementations can be found on many of Eurocopter's helicopter range, such as the
Other than Airbus Helicopters and its predecessors, other companies have also made use of Fenestron anti-torque arrangements. One such rotorcraft was the American
Advantages
- Increased safety for people on the ground because the enclosure provides peripheral protection.[5][18]
- Greatly reduced noise and vibration due to the enclosure of the blade tips and greater number of blades.[5][18]
- A decrease in power requirements during the cruise phase of flight.[19]
- Typically lighter and smaller than conventional counterparts.[20][9][N 2]
- A lower susceptibility to foreign object damage because the enclosure makes it less likely to suck in loose objects such as small rocks.[12]
- Enhanced anti-torque control efficiency and reduction in pilot workload.[22]
- 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,[23] power requirement,[24] and air resistance brought by the enclosure;
- Higher construction and purchasing cost.[19]
- Increase in power required during the hover phase of flight.[19]
See also
References
Notes
- ^ Born in Aix-en-Provence and fiercely loyal to his roots, Paul Fabre chose the name fenestrou, a Provencal word meaning small round window, to designate his shrouded rotor invention.[2]
- ^ A computational simulation has suggested that the maximum achievable thrust of a Fenestron is twice as high and at identical power, thrust was slightly greater than for a conventional rotor of the same diameter.[21]
Citations
- ^ Leishman 2006, p. 321.
- ^ a b c d e Colonges, Monique. "History of the fenestron." Airbus Helicopters, Retrieved: 16 April 2018.
- ^ Prouty, Ray. Helicopter Aerodynamics, Helobooks, 1985, 2004. p. 266.
- ^ "30 Years of Innovation." fenestron.com.[permanent dead link]
- ^ a b c d e f g Huber, Mike. "The Fenestron Turns 50." AIN Online, 12 April 2018.
- ^ Corda 2017, pp. 33–34.
- ^ Leishman 2006, p. 324.
- ^ "Publication Number: 572417 - Improvements in helicopters." patentscope.wipo.int, 24 May 1943.
- ^ a b Prouty 2009, p. 266.
- ^ Leishman 2006, p. 43.
- ^ a b Prouty 2009, p. 267.
- ^ a b c "Cabri G2 Fenestron." Archived 2018-04-17 at the Wayback Machine collegeaviationdegree.com, Retrieved: 16 April 2018.
- ^ "Fenestron, the Origins: Episode One." Airbus Helicopters, 12 April 2018.
- ^ "Airbus Helicopters’ new EC145 T2 is certified." Archived 2018-04-19 at the Wayback Machine Airbus Helicopters, 17 April 2014.
- ^ a b Prouty 2009, pp. 266–267.
- ^ Apostolo 1984, p. 89.
- ^ Leishman 2006, p. 46.
- ^ a b Gey 2004, p. 180.
- ^ a b c Newman 2005, [page needed]
- ^ Leishman 2006, pp. 315, 321.
- University of Maryland, 2008. Retrieved: 15 March 2013.
- ^ "More innovation with Eurocopter's signature tail rotor" Archived 2018-04-17 at the Wayback Machine. Airbus Helicopters, 8 March 2011.
- ^ Corda 2017, p. 34.
- ^ Johnson 2013, p. 282.
Bibliography
- Corda, Stephen. Introduction to Aerospace Engineering with a Flight Test Perspective. John Wiley & Sons, 2017. ISBN 1-1189-5338-X.
- Gay, Daniel. Composite Materials: Design and Applications. CRC Press, 2014. ISBN 1-4665-8487-4.
- Johnson, Wayne. "Rotorcraft Aeromechanics." Cambridge University Press, 2013. ISBN 1-1073-5528-1.
- Leishman, Gordon L. "Principles of Helicopter Aerodynamics." Cambridge University Press, 2006. ISBN 0-5218-5860-7.
- Newman, Ron. The Technical, Aerodynamic & Performance Aspects of a Helicopter. BookBaby, 2015. ISBN 1-4835-5878-9.
- Prouty, Ray. Helicopter Aerodynamics Volume I. Lulu.com, 2009. ISBN 0-5570-8991-3.