Commercial Aircraft with Passengers
Credit: Wenjie Dong/Getty Images

You’re flying with more people than ever before.

According to data from the Bureau of Transportation Statistics (BTS), airlines smashed records last year by transporting 741 million passengers across the country.

Over the past 10 years, there has been a 9.2 percent increase in passengers. But, at the same time, there were 18.5 percent fewer flights available when that number peaked than in 2005.

The average flight now carries 91 passengers. About 10 years ago, that number was 69.

Earlier this year, airlines set a record for passenger load factor (a figure that measures efficiency and how well planes are stocked with passengers). Around the world, flights are operating at about 82 percent full, according to the International Air Transport Association (IATA).

While there are more passengers flying than ever before, the trend is also due to something called “upgauging.”

Upgauging is aviation industry lingo for when airlines use larger aircraft that can accommodate more passengers. By allowing more people onto each flight, airlines can lower the operation cost per passenger.

"The economics on the cost side always favor a larger aircraft,” Seth Kaplan, managing partner for Airline Weekly, told Travel Weekly. "Upgauging also saves on engine maintenance and airport fees. There are just powerful incentives to try and get more seats per flights."

Anybody who has been paying attention to the saga of the “incredible shrinking airline seat” will recognize the forms of seat densification. In the mid-1990s, standard seating on a Boeing 777 was nine across. Now it’s common to see 10 seats in a row.

But there is a limit to how far upgauging can go. Over the past few years, airlines have retired some notable jumbo aircraft in favor of smaller, more fuel-efficient jets. Last year, United retired its final Boeing 747, once referred to as the “Queen of the Skies.” And earlier this year, the future of the jumbo A380 aircraft was brought into question. Due to one life-saving order from Emirates, the double-decker plane will remain in production for another 10 years. But because of its sheer size (making it difficult to land at standard airports), the plane’s future is uncertain beyond that.