Abstract
A new flight mode in birds that decreases the energy costs is described. This flight mode consists basically of a powered-glide phase and a climb phase. These phases constitute a cycle that is continually performed. The powered-glide phase shows a reduced wing flapping for generating thrust at an intermediate level. Other than a glide with a fixed wing posture, there is an energy support in the powered glide. It is shown that powered-gliding/climbing flight enables a decrease of the energy costs to yield a low fuel consumption. The powered-glide phase is determinative for achieving the decrease of the energy costs. The results based on this effect suggest that powered-gliding/climbing flight shows the lowest fuel consumption per range when compared with other travel flight modes including the flight at constant altitude. It has been found that birds perform continual altitude changes in long-distance flights rather than flying at a constant altitude. There is evidence based on observations and measurements that the descents in these altitude changes take place as powered glides. This suggests that long-distance flights with altitude changes consist of powered-gliding/climbing flight with repeated cycles.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
