The reason most commercial airplanes crash is because of inadequate maintenance. The Third World is particularly known for its nonexistent maintenance in all domains. The image in my mind is a taxi we rode in India where the front wheel was attached with a wire or a shuttle in Cameroon where the door was latched with rubber bands.
Let me discuss the reasons why. The two countries with the best maintenance competence are Japan and Germany. This is evident in their engineering. Their cars are designed to facilitate maintenance. They’re societies are very clean and well maintained.
Because airplanes have such great risk built into their operation they must give the highest priority to maintenance. As one of my own passengers commented upon take off where I was the pilot and she was anxious about turbulence, "You can't pull over and stop can you?"
Maintenance is built into all Japanese life because it was founded as a rice culture and rice, with its irrigation needs, is very maintenance oriented. I don’t know the reasons for Germany’s attention to maintenance.
Airplanes are usually serviced in the First World. But they operate invariably in the Third World which is where the failure of maintenance results in a high number of commercial crashes.
Airplane safety is extremely high and fatalities terribly low, but we automatically assume this does not apply in Third World circumstances. We just need to understand that the absence of a maintenance culture is the reason.