First International Symposium on Flutter and its Application (May 15-17, 2016. Mielparque-tokyo), Minato-ku, Tokyo, Japan Animal wings are usually made of elastic materials and thus have different characteristics from conventional airplane wing made of hard stuff. The elasticity of wing provides merits such as a large straight-line stability but causes a serious problem of flutter. This study investigates how animals withstand this problem focusing on the bird wing. The wing of birds is composed of many feathers, the representative of which is a primary feather. Interestingly, flutters are hardly observed in the primary feathers. The reflection in the primary feather was supposed to be the key factor of flutter inhibition. The wind tunnel tests with feather models with and without reflection were conducted and it was confirmed that the feather with reflection more effectively inhibited the flutter generation than the feather without reflection. 形態: カラー図版あり Physical characteristics: Original contains color illustrations 資料番号: AA1630046043 レポート番号: JAXA-SP-16-008E