The Department of Transportation's Office of the Inspector General has begun an audit of the FAA's oversight of aircraft evacuation procedures and the impact of various seat configurations on evacuations.
The audit comes at the request of Rep. Peter DeFazio (D-Ore.), the ranking member of the House transportation committee, and Rick Larsen (D-Wash.), the top Democrat on the House aviation subcommittee.
Under FAA rules, aircraft must be able to be evacuated in 90 seconds or less. The Inspector General's office said evacuation standards have not been significantly updated since 1990.
"Significant changes in the industry and consumer behavior have occurred since 1990," it said in a news release. "For example, the number of aircraft seats and passengers have increased, but seat size and distance between seats, known as seat pitch, have decreased. Passengers' reliance on carry-on luggage has also increased."
The report began 10-and-a-half months after a federal appeals court ordered the FAA to review seat sizes and the distance between rows on commercial aircraft.
The FAA asserts that the interior configurations currently used by airlines have passed required safety and certification tests. But the court objected to the FAA practice of not releasing those tests in order to protect the proprietary information of manufacturers.
The FAA did not respond to an inquiry about whether it has taken any action pursuant to that July 2017 court ruling, but Paul Hudson, president of Flyers Rights, said the agency has yet to do so. Flyers Rights is the consumer advocacy group whose request for the FAA to set seat-size standards paved the way for the ruling.
Pressure on the agency to begin governing aircraft interior configurations could also be coming from Congress. The House version of this year's FAA reauthorization bill, which passed out of the chamber in April, would direct the FAA to set minimum standards for seat pitch and width within a year. The Senate has not yet passed a companion FAA reauthorization bill.
According to consumer advocates, the average pitch on an economy U.S. airline seat has shrunk from 35 inches in the 1970s to 31 inches today. Jason Rabinowitz, data research manager for the flight amenities website Routehappy, agreed with that assessment in an interview last year, but he noted that airlines have also moved toward slim-lined seats, which can allow for more legroom per inch than the thicker seats found in older jetliner interiors.
Spirit and Frontier offer the smallest pitches in the industry, at 28 inches.
Rabinowitz said that seat widths haven't changed significantly in recent years, with the exception of some carriers' Boeing 777s, on which they have squeezed widths from 18.5 inches to 17.5 inches to allow for the installation of 10 seats per row rather than nine.
In an email, the trade organization Airlines for America said it supports the federal government's role in determining what seat size is safe, but spokeswoman Alison McAfee wrote, "The idea that airlines would intentionally downgrade the flying experience through changes in seat configurations or undermine safety is a flawed premise.
"Airlines continue to invest in a wide range of innovative technologies to maximize personal space in the cabin while maintaining a level of comfort passengers expect, and safety is and will always be at the forefront of those decisions."
In its news release, the Inspector General's office cited an October 2016 American Airlines flight that was evacuated because of an engine fire. The flight took two minutes and twenty-one seconds to evacuate, according to Rep. Steve Cohen (D-Tenn.), who has been a leading congressional advocate of seat size regulation.
The office said it would assess the FAA's development and updating of aircraft emergency evacuation standards as well as its process for determining if aircraft as currently configured meet evacuation standards.