Editing Wingtip device (section)

== Use on rotating blades ==

Wingtip devices are also used on rotating [[Propeller (aircraft)|propeller]], [[helicopter rotor]], and [[wind turbine]] blades to reduce drag, reduce diameter, reduce noise and/or improve efficiency. By reducing aircraft blade tip vortices interacting with the ground surface during [[taxiing]], [[takeoff]], and [[Hover (helicopter)|hover]], these devices can reduce damage from dirt and small stones picked up in the vortices.<ref name=HP>{{cite web |url= http://www.hartzellpropellers.com/product_support/support_faqs.htm |title= What is a Q-Tip propeller? What are its advantages? |work= Product Support: Frequently Asked Questions |publisher= [[Hartzell Propeller]] |quote= Aerodynamic improvements include a reduced diameter and decreased tip speeds. This results in quieter operation and reduced tip vortices. The 90° bend reduces the vortices that, on traditional blades, pick up debris that can contact the blades and cause nicks, gouges and scratches. |url-status= bot: unknown |archive-url= https://web.archive.org/web/20010318034156/http://www.hartzellpropellers.com/product_support/support_faqs.htm |archive-date= 2001-03-18 }}</ref>

<gallery mode="packed" heights="140px">
File:Merlin at RIAT 2009.JPG|[[AgustaWestland AW101]] Merlin showing [[BERP rotor]] with distinctive blade tip profile
File:Hercules.propeller.arp.jpg|[[C-130J Super Hercules]] showing [[scimitar propeller]]s with raked tips
File:WindTurbine Rotor Winglet.JPG|Detail view of the wingtip device on a wind turbine rotor-blade
File:Ceiling fan at Chicago O'Hare Airport.jpg|Ceiling fan with wingtip devices
</gallery>

=== Rotorcraft applications ===
[[File:ILA 2018, Schönefeld (1X7A5334).jpg|thumb|Wingtip device on a [[NHIndustries NH90]]]]
The main rotor blades of the [[AgustaWestland AW101]] (formerly the EH101) have a distinctive tip shape; pilots have found that this rotor design alters the downwash field and reduces [[Brownout (aviation)|brownout]] which limits visibility in dusty areas and leads to accidents.<ref name=NG>{{cite web|url=http://ngccommunity.nationalgeographic.com/ngcblogs/explorer/engineering/|first=Gareth|last=Harvey|title=Super Chopper : Life-Saving Features: No More Brown-Outs|publisher=National Geographic Channel|work=Engineering Archives|access-date=August 1, 2009|date=November 28, 2005|quote=To counteract this, the EH101's 'winged-tip' rotor blades create what its pilots call the "donut effect" – a circular window of clear air inside the dust storm that allows them to see the ground as they come in to land.|url-status=dead|archive-url=https://web.archive.org/web/20090721184318/http://ngccommunity.nationalgeographic.com/ngcblogs/explorer/engineering/|archive-date=July 21, 2009}}</ref>

=== Propeller applications ===
[[Hartzell Propeller]] developed their "Q-tip" propeller used on the [[Piper PA-42 Cheyenne]] and several other fixed-wing aircraft types by bending the blade tips back at a 90-degree angle to get the same [[thrust]] from a reduced diameter propeller disk; the reduced propeller tip speed reduces noise, according to the manufacturer.<ref name=HP/> Modern [[scimitar propeller]]s have increased [[sweepback]] at the tips, resembling a raked tip on an aircraft wing.

=== Other applications ===
Some [[ceiling fan]]s have wingtip devices. Fan manufacturer [[Big Ass Fans]] has claimed that their Isis fan, equipped with wingtip devices, has superior efficiency.<ref>{{cite news |author= Nino Machetti |url= http://earthtechling.com/2010/05/isis-ceiling-fan-claims-higher-energy-efficiency/ |title= Isis ceiling fan claims higher efficiency |date= May 10, 2010 |publisher= EarthTechling}}</ref> However, for certain high-volume, low-speed designs, wingtip devices may not improve efficiency.<ref name="macroair">{{cite news |author= Eddie Boyd |url= https://macroairfans.com/blog/winglets-help-hindrance-hvls-fan-performance/ |title= Winglets: Help or Hindrance to HVLS Fan Performance?|publisher= MacroAir |date= February 4, 2014}}</ref>
Another application of the same principle was introduced to the keel of the "America's Cup"- winning Australian yacht [[Australia II]] of 1982, designed by [[Ben Lexcen]].