Flights take longer now than they did 40 years ago - here's why

Business Insider recently taught us why flights today take longer to complete than they did 40 or 50 years ago. For example, in 1973 a flight from New York to Houston took about two hours and 37 minutes - today, you'll spend over an hour more than that on the same journey.

Since technology has only improved since then, what gives?

The answer is simple: fuel efficiency.

Airlines can save millions of dollars a year simply by flying their planes a little slower, and yes, by keeping you in that middle seat for longer. Fuel bills make up the vast majority of airlines' operating costs, so even minor slowdowns can have a major impact on budgets.

Fuel costs are behind every penny-pinching measure airlines have taken in the past several years, like charging extra for checked baggage and reducing food services as well as supplies on board. These measures lighten the load and thus increase flight efficiency. According to Reuters, jet fuel consumption peaked in 2005, and has since fallen over 15%, thanks in part to these measures.

Airlines also pad their schedules to account for unexpected delays and time spent sitting on the runway before takeoff or after landing, which makes it seem like flights are even longer than they used to be. So if your flight arrives early, it's not because of tailwind, it just means that there were no serious delays.