Current preliminary aircraft design cycles use empirical relations to great the wing and power loading diagrams to size the aircraft and its engine. These empirical relations are based on historical aircraft data to relate the aircraft weight to engine power. To enhance the design capability for novel propeller aircraft types and increase the accuracy in general, a takeoff performance analysis and propeller sizing method is developed to create analytical and physics based takeoff and cruise constraints. The sizing method focusses on takeoff conditions, taking into account the low speed aerodynamic effects on the propeller and the resulting effect on the takeoff performance. The point mass takeoff performance model and BEM propeller analysis iterate the propeller sizing parameters; number of blades and chord ratio factor to determine the propeller that precisely achieves the required takeoff distance. Two case studies with reference aircraft are presented to demonstrate the impact of the developed sizing method on the preliminary aircraft and engine design solution with respect to reality and the empirical method. The results show the created constraints follow the same trends, however the power loading takeoff constraint is lower than the empirical constraint. ... Read more

This report is the final report in a series of four reports that deals with the design of an advanced regional aircraft. The first step in the design is to determine the overall configuration of the ARA. By identifying the feasible configurations based on a literature study and performing a trade-o_, the conventional low wing with GTF engines underneath the wings configuration is found to be the optimal configuration for the ARA. After selecting the aircraft configuration, the preliminary subsystem design is initiated. Class I and II weight estimations are performed and a MTOW of 34500kg is determined. The selected wing planform is a two-piece complex sweptback planform with a wing area of 105m2 and a wing span of 30.7m. The thrust will be provided by two PW1217G GTFs with a maximum thrust of 76kN each. For the fuselage design, several configuration options are analysed taking into account structural and aerodynamic considerations. A trade-o_ is performed and the 4 abreast configuration with cargo in the tail is found to be the best choice. The tricycle configuration is chosen for the landing gear. The main gear is positioned 17.1m from the nose, while the nose gear is positioned 3.6m from the nose. The control surfaces comprising ailerons, spoilerons, elevators and rudder, are sized for extreme load cases. For roll control at low speeds outboard ailerons are used and spoilerons are used for roll control at high speeds. The elevators are sized to meet take-o_ and trim requirements. The rudder is sized to counteract the yawing moment with one-engine inoperative. Furthermore, the high-lift devices are sized. It is found that in order to fulfill landing and take-o_ requirements double-slotted Fowler flaps are required... ... Read more