On February 2nd, 2008 we did high speed taxi and preliminary flight tests for the rotoplane. The results are positive, but the airplane design leaves some to be desired. The most important result of the test is that the airplane has enough yaw stability to maintain straight and level flight due to the gyroscope-controlled thrust vectoring. Many high speed taxis without take offs were conducted and then we graduated to low altitude flights (1-3 feet above ground).
All flights unfolded in approximately the same manner. The takeoff runs were smooth and transition into flight was easily accomplished with pitch control from the canard. We were able to maintain level pitch attitude and the wings parallel to the runway as well as maintain heading. The problems were always with the landings. The airplane can maintain heading when it’s motor is powered because it can vector its thrust. Upon reducing the thrust to land, the ability to maintain heading is lost and one wing slips ahead of the other. During this slip one wing generates more lift than the other sending the plane into an awkward sort of cartwheel/roll landing as you’ll see in the videos. Fortunately, the airplane isn’t designed to land in a conventional manner.
Because the landing gear was an afterthought, designed solely for high speed taxis and initial testing, it interferes with large rotations of the main wings and thus we cannot attempt an autorotation landing from a ground roll take off. We would have liked to fly again and take off without landing gear so that we can attempt an autorotation, but it began to rain and we will have to wait for better weather.
I believe, based on my experience with the mockup as can be see in the droptest video, that we could accomplish an autorotation. Although the current airplane is heavier than that used in the droptest, the wings are much stronger and hopefully will not break as one did in the droptest. In fact, autorotation simulations in Matlab and wing loading tests confirm that the wings are strong enough and we look forward to a chance to autorotate.
See video below.
All flights unfolded in approximately the same manner. The takeoff runs were smooth and transition into flight was easily accomplished with pitch control from the canard. We were able to maintain level pitch attitude and the wings parallel to the runway as well as maintain heading. The problems were always with the landings. The airplane can maintain heading when it’s motor is powered because it can vector its thrust. Upon reducing the thrust to land, the ability to maintain heading is lost and one wing slips ahead of the other. During this slip one wing generates more lift than the other sending the plane into an awkward sort of cartwheel/roll landing as you’ll see in the videos. Fortunately, the airplane isn’t designed to land in a conventional manner.
Because the landing gear was an afterthought, designed solely for high speed taxis and initial testing, it interferes with large rotations of the main wings and thus we cannot attempt an autorotation landing from a ground roll take off. We would have liked to fly again and take off without landing gear so that we can attempt an autorotation, but it began to rain and we will have to wait for better weather.
I believe, based on my experience with the mockup as can be see in the droptest video, that we could accomplish an autorotation. Although the current airplane is heavier than that used in the droptest, the wings are much stronger and hopefully will not break as one did in the droptest. In fact, autorotation simulations in Matlab and wing loading tests confirm that the wings are strong enough and we look forward to a chance to autorotate.
See video below.
RSS Feed
