A leak from an air conditioner unit caused the sickening fumes that forced a Frontier Airlines flight to declare an emergency and return to Long Island MacArthur Airport just 15 minutes after taking off last November, according to the Federal Aviation Administration.
Bound for Myrtle Beach, South Carolina, Flight 1851 with 218 people aboard landed safely at about 12:25 p.m. on Nov. 1 after fumes circulated in the cockpit, where the pilots donned oxygen masks, and in the galley area, the investigation found.
“On takeoff, strong odor occurred in the cabin, passengers and crew members started covering their noses,” a Frontier Airlines employee told investigators according to FAA records obtained through the Freedom of Information Act.
One flight attendant became nauseous and vomited in the lavatory; several passengers also felt nauseous, the records said. “We were met by airport firefighters, airport staff and police upon arrival,” another employee told investigators. The stricken flight attendant was hospitalized; a co-worker and several passengers were evaluated by emergency medical technicians, the airline workers added.
Frontier Airlines did not respond to requests for comment. FAA policies preclude comment on such reports.
Airlines must inform the federal watchdog when fumes are detected, an FAA spokesman said by email. “The FAA believes that the cabin environment in the vast majority of commercial flights is safe,” he said. In 2015, for example, only about 98 “fume events” were reported, out of the millions of U.S. flights that year, he said.
Still, problems with the “environmental control system” that shields passengers and crew from the brutal cold and low atmospheric pressure at high altitudes, are not uncommon.
Air conditioning is a crucial part of environmental control systems. Problems with those systems ranked sixth out of 24,409 system component failures or malfunctions found from January 1993 through January 2011, said a report by the NASA Glenn Research Center in Cleveland.
There were 1,619 environmental control system problems, the 2014 report said. The top categories were: propulsion systems, 3,240; monitoring and management, 2,661; landing gear, 2,155; electrical power, 1,933; and control surface, 1,817.
When fumes enter cabins, “The most common cause is a contaminant in the bleed air system, and it’s fairly common,” said Kevin R. Kuhlmann, an aviation and aerospace science professor at Metropolitan State University of Denver.
For decades, he said, jets have used these “bleed” systems to funnel air rushing into engine compressors, before it reaches the fuel, into the air conditioning. The systems have “probably been used ever since jet engines were invented,” Kuhlmann said.
While newer aircraft are starting to use different systems, the cost of retrofitting jets would be prohibitive, he said.
Chad Kendall, assistant professor of aeronautics at Florida’s Jacksonville University, said: “A captain’s responsibility is the safety of their crew and passengers and this captain made the right decision to return to the departure airport.”
Frontier’s Airbus 321 resumed flying one day after mechanics fixed the air conditioning — without incident, FAA records show.