Question: How do you make aircraft

Good question. A great question to consider problem solving, which is where most engineering starts. There are so many different types of aircraft that one must go through a bit of problem analysis and definition to start with. Typical questions might be:
• What is the purpose of our aircraft? E.g.:
o Military strike
o Military transport
o Commercial freight
o Commercial passenger
o Private passenger
o Private light aircraft
• What distance do we want our aircraft to fly?
• What altitude do we want our aircraft to achieve?
• What speed do we want our aircraft to achieve?
• What pay-load do we want our aircraft to carry? Number of passengers, tonnes of cargo?
• How many crew will be required?
From the definition determined from above one can then begin to sketch out ideas for:
• Fuselage design
• Wing design
• Undercarriage arrangements
• Power/thrust required from the engines
• Engine types and arrangements
From sketch designs there will then be a period of developing detailed designs of everything that will go into the plane, and I mean everything.
Finally, the completed design is divided into discrete packages of work for a collection of manufacturers to work on. Each manufacturer works in their key skill area. A sequence of work and sequence of deliveries will be arranged so that the complete aircraft can be built as efficiently as possible, not delayed by waiting for vital components to arrive. A lot of the manufacture will be to complete modules that are then connected together. For example, the Airbus aircraft have their wings built in England and then attached to the fuselage built in France.
To achieve the perfect integration and connection of the thousands of modules and components means that Engineers must complete their designs with full definition of the requirements and precise limits on the accuracy of every measurement. At the manufacturing stage other Engineers must ensure that the manufactured product precisely reflects the design.