Why is the manufacturing process of an aircraft mostly manual?
Although robots have taken over many jobs in the process of manufacturing things like cars, airliners are much larger and more complex. In some ways it has more in common with constructing a building than assembling a vehicle. There is a much larger variety of tasks to be performed over a much larger area.

That being said, many parts of the manufacturing process are completed by robots. For example, Gemcor makes machines that automatically drill aircraft wings and fasten them with rivets and bolts.



Robots are also used in manufacturing large composites. You'll notice how massive these machines are, and they are only completing one task on one component. They are very good at tasks that require one or more of force, repetition, and accuracy.

However, so much of the process is not economical to be done with robots. A robot specializes in one task or one type of task, while humans can do many different tasks. Many tasks involve working in tight spaces, which humans can do better than a large robot. Tasks like installing wires require dexterity as well, which humans are better at.