Airlines invest significantly in airplane interiors to ensure a comfortable travel experience. This investment includes maintenance and brand-new interiors, such as seats and inflight entertainment. The goal is to keep passengers happy, even if they are flying on older planes.

Some airplanes in service are up to 45 years old, but still safely fly commercial routes. Airlines renovate the interiors of these planes to make them feel newer. For example, United Airlines has updated the interiors of some of its Boeing 767s, which have been in service since 1991.

Further details on airline investments in airplane interiors are available from the source, including more information on specific airlines and their fleets.