With this conceptual layout and mass estimation completed you can move onto the initial performance estimation - the drag calculation. Your conceptual representation should include such variables as maximum take-off weight, cruise speed, and a sketch of the conceptual aircraft layout. With this information clearly defined you can start to generate a conceptual representation of the aircraft by following the steps outlined in the previous posts. What is the approximate mass of the aircraft (EW, MTOW, payload).Is take-off performance or cruise speed of greater importance to fulfill the mission requirement?.Does the aircraft require cabin pressurization?.Define the typical airports/landing strips from which the aircraft will operate.At what altitude will the aircraft predominantly operate?.What is the size and mass of the intended payload (passengers, cargo, weapons)?.What is the primary mission - passenger, cargo, maritime patrol, military fighter, troop transport etc?.Some typical questions that should be asked before generating a new concept are: It is very important to clearly define the intended purpose of the aircraft before going ahead with the initial sketches and layout. User Requirement SpecificationĮvery new aircraft starts with a list of user requirements. If you haven’t done so already, read through the above posts before continuing with this tutorial. Part 8: Horizontal and Vertical Tail Design In order to complete this tutorial you will need to be familiar with the following concepts outlined in previous posts: It’s now time to take the next step as we begin to build a mathematical performance model, which will enable us to estimate the total drag produced by the design as a function of the chosen aircraft geometry.
Looking at and using past aircraft data provides a solid starting point in a new design but it does not confirm that we will meet the mission requirements set out for the design. Up to this point in the series we have used many “rules-of-thumb” or studied existing aircraft when generating a concept aircraft. Now we put it all together and run through a preliminary drag estimation of a new aircraft design. In the previous posts we have covered the fundamentals of flight, studied the wing, fuselage and empennage, and have been introduced to aerodynamic lift, drag and moment coefficients. Welcome to Part 9 in the Fundamentals of Aircraft Design series.