New HPA exhibited in 3M Sendai Science Museum

Human-powered aircraft built by team

Human-powered aircraft built by team “Windnauts”, which is HPA club in Tohoku university, is exhibited in 3M Sendai Science Museum.
[Photo by Contri – https://www.flickr.com/photos/contri/17159083597/. License: cc-by-sa-2.0]

A new Human-powered Aircraft (HPA) have been exhibited in 3M Sendai Science Museum located in Sendai city, Miyagi, Japan since Nov. 29,2014. The aeroplane is the fifth HPA, four aeroplanes and one helicopter, which is permanent exhibited in Japanese museums.

The HPA had been rebuilt by current and senior members of “Windnauts” which is the HPA club at Tohoku university based on their two HPAs winning Japan International Birdman Rally (JIBR) in 2011 and 2012. Their winning of 2011 is very famous in Japan. Because they achieved the dramatic win with 18.7 km (11.6 mi) of straight distance, about 35 km (21.7 mi) fo gross against moch of loss distance by erratic winds and malfunction of GPS/communication devices during their flight and their very heavy adversity caused by 2011 Tohoku earthquake. Many people especially  have been moved by fighting spirit of Takuma Nakamura who was the pilot at the 2011 competition with his encouraging himself shown by on-board camera.

 

This video is their 2011 flight in tv program with English sub. Because the exhibited HPA has combined design of 2011 model and 2012 modes as described above, The cockpit fairing of the exhibited HPA is different from the 2011 model in the video but similar to 2012 model.

 

In technical view, the HPA looks like MIT Daedalus and it has similar configuration such as CFRP tubular frame structure, single wire braced high wing with DAE airfoils, recumbent style pilot position and single tractor propeller driven by shaft drive systems. The Windnauts HPA is 32 m (105 feet) span and 30 kg (66 pounds) weight, which is almost the least span-to-weight ratio among HPAs participating in JIBR. Note that Japanese HPAs built by student club tend to have some more span-to-weight ratio than MIT Daedalus by several factors such as less material grade, much safety margin and/or their technical deficiency etc. One of noteworthy characteristics of the Windnauts HPA is dihedral, which is known as “initial dihedral” in HPA community of Japan. Most of Japanese Daedalus like HPAs do not have initial dihedral same as MIT Daedalus. I guess that most of Japanese HPA teams may assume that flexure of wing by lift make significant dihedral during steady flight and the initial dihedral may lead to break of wing spar. The main purpose of the initial dihedral of Windnauts HPAs is not intended to improve rolling stability but to reduce drag and weight by omitting the king-post for bracing landing wire of wing. Of course, king-post and landing wire cause increase of drag and weight. Nevertheless, most of Japanese HPAs for distance section in JIBR equip the king-post and landing wire with the intention to avoid divergence caused by coupling effect between increase of air speed and displacement of outboard to upper direction by increase of lift during non-steady flight from less speed condition caused by too short runway of JIBR to steady flight.

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poor English better than Japanese – thank you

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