Aircraft design process
Similar to, but more exacting than, the usual engineering design process, the technique is highly iterative, involving high-level configuration tradeoffs, a mixture of analysis and testing and the detailed examination of the adequacy of every part of the structure.
Some aircraft have specific missions, for instance, amphibious airplanes have a unique design that allows them to operate from both land and water, some fighters, like the Harrier jump jet, have VTOL (vertical take-off and landing) ability, helicopters have the ability to hover over an area for a period of time.
Competition leads to companies striving for better efficiency in the design without compromising performance and incorporating new techniques and technology.
[5] In the 1950s and '60s, unattainable project goals were regularly set, but then abandoned, whereas today troubled programs like the Boeing 787 and the Lockheed Martin F-35 have proven far more costly and complex to develop than expected.
Model-based systems engineering predicts potentially problematic interactions, while computational analysis and optimization allows designers to explore more options early in the process.
Once impossible to design or construct, these can now be 3D printed, but they have yet to prove their utility in applications like the Northrop Grumman B-21 or the re-engined A320neo and 737 MAX.
[12] Newer, environmentally friendly fuels have been developed[13] and the use of recyclable materials in manufacturing[14] have helped reduce the ecological impact due to aircraft.
[20] The responsibility for airworthiness lies with the national civil aviation regulatory bodies, manufacturers, as well as owners and operators.
The aviation operators include the passenger and cargo airliners, air forces and owners of private aircraft.
[24] So the passenger aircraft are designed in such a way that seating arrangements are away from areas likely to be intruded in an accident, such as near a propeller, engine nacelle undercarriage etc.
In general aviation a large number of light aircraft are designed and built by amateur hobbyists and enthusiasts.
In the 1940s, several engineers started looking for ways to automate and simplify the calculation process and many relations and semi-empirical formulas were developed.
[33] The wing must be designed and tested to ensure it can withstand the maximum loads imposed by maneuvering, and by atmospheric gusts.
The aircraft structure focuses not only on strength, aeroelasticity, durability, damage tolerance, stability, but also on fail-safety, corrosion resistance, maintainability and ease of manufacturing.
The structure must be able to withstand the stresses caused by cabin pressurization, if fitted, turbulence and engine or rotor vibrations.
Fundamental aspects such as fuselage shape, wing configuration and location, engine size and type are all determined at this stage.
The final product is a conceptual layout of the aircraft configuration on paper or computer screen, to be reviewed by engineers and other designers.
In this phase, wind tunnel testing and computational fluid dynamic calculations of the flow field around the aircraft are done.
[41] At this point several designs, though perfectly capable of flight and performance, might have been opted out of production due to their being economically nonviable.
[42] All aerodynamic, structural, propulsion, control and performance aspects have already been covered in the preliminary design phase and only the manufacturing remains.
[43] An existing aircraft program can be developed for performance and economy gains by stretching the fuselage, increasing the MTOW, enhancing the aerodynamics, installing new engines, new wings or new avionics.
