The Ornicopter concept is a single-rotor, tailless configuration. By actively flapping its blades, the Ornicopter rotor can propel itself to rotate, and hence does not need a tail rotor. In previous research, the Ornicopter concept has been compared with the Bo-105 conventional helicopter from various aspects, while the Ornicopter has the same design parameters as the Bo-105. Comparisons show that the Ornicopter has one major drawback, namely a small flight envelope. To improve the Ornicopter performance and understand how the Ornicopter should be designed, in this paper, the Ornicopter design is unfrozen and optimized for the flight envelope. The optimization result shows that with a proper design, the Ornicopter performance can be improved dramatically. A similar flight envelope as the Bo-105 can be achieved for the Ornicopter. However, the Ornicopter requires higher power than the Bo-105 due to the inherent characteristics of this concept. @en