Airline seats are shrinking. Meanwhile, people are getting bigger

It's not just long security lines, luggage fees or flight delays that could make this upcoming holiday travel season a nightmare. One of the biggest complaints from passengers is the size of seats.

Just weeks ahead of one of the busiest times of the year for airplane travel, six Democratic senators pressing the Federal Aviation Administration to stop any further restriction of plane seat sizes. Their reason? Passenger safety.

An overwhelming number of customers responded to a request for feedback from the FAA about regulating the size of seats.

Many complained the seats on domestic flights are "very small" and "uncomfortable," while others complained the seats are particularly uncomfortable for tall people.

There were over 26,000 comments in the FAA's public forum, with travelers telling the agency everything from "flying has become torture" to "seats are too small and leg room is too small."

Not only do smaller seats affect comfort, they are also a safety issue.

"If the seats are too cramped together, that's going to make it hard for many folks to get off that aircraft quickly," said Scott Keyes, founder of Scott's Cheap Flights.

Flyer's Rights, a passenger advocacy group, is pushing the federal government to step in and stop airlines from making seats even smaller.

"If we don't get minimum standards, then airlines will continue to shrink the seats," said Paul Hudson from Flyer's Rights.

Since the 1990s, the width of most airplane seats shrunk from 18 inches to 16 inches, and the distance between seat backs decreased from 35 inches to sometimes less than 28.

"People have been getting larger, both in weight and in height," Hudson said. "The seats on the other hand, have been shrinking. So we feel this is a safety risk."

According to Scott's Cheap Flights, JetBlue, Southwest, and mainstream airlines like Delta, American and United tend to have the most legroom.

Budget airlines like Spirit, Frontier and Allegiant often have the least.

At New York's LaGuardia Airport, many passengers say they welcome some new regulations.

"I think it's a good idea, because people come in different shapes and sizes," one traveler said.