Define the aircraft requirements
Determine payload, range, speed, and runway needs
Choose the aircraft type and configuration
Design the wing, fuselage, tail, and control surfaces
Select suitable materials
Design the propulsion system
Design the landing gear
Design the avionics and flight control systems
Perform aerodynamic analysis and structural calculations
Build scale models and prototypes
Test components and systems
Assemble the full aircraft
Conduct ground tests
Conduct flight tests
Refine the design based on test results
Certify the aircraft according to regulations
Begin production and maintenance planning