I have a couple of questions about cabin seats on new commercial aircraft:
1. Do Boeing and Airbus produce their own seats? Or do they offer standard seats through subcontractors? If Boeing/Airbus provides the seats, do they tend to favor certain manufacturers.
2. Do airlines purchase seats separately from new aircraft? Do they tend to choose from selected suppliers to Boeing and Airbus?
3. Where are they usually installed? - at the Boeing/Airbus factory or at the airline's headquarters? Which is the most popular?
Many thanks for anyone's assistance.