If you’re one of the millions of passengers who boarded a flight during this summer’s heat wave, only to wish, minutes later, you had brought your winter parka, you’ll no doubt wonder, Why is the plane so cold?
It’s a question that has baffled flyers for decades.
The search term “cold plane” generates several posts in air travel chat rooms. In a common gripe, a Southwest Airlines customer complained that the two-hour flight to Florida was so cold “we could see our breath.”
Yet despite strong public interest in cabin air quality—especially during the Covid-19 pandemic—there are no industry-wide standards for in-flight thermostats. The Regulated by the Federal Aviation Administration Certain aspects of the cabin ventilation system, such as indicating how much fresh air will be circulated per minute. But the agency stopped short of setting a minimum or maximum temperature.
According to those who spend the most time on the plane—the flight crew—there is a wide range of these temperatures, depending on the aircraft, flight phase and other factors.
The Association of Flight Attendants, a union that represents 50,000 members working at more than 20 airlines, has been campaigning for years for the federal government to set standards for cabin temperatures, recommending a range of 65 to 75 degrees Fahrenheit (though 65 degrees Fahrenheit). (For many passengers still firmly in light-sweater territory).
Why is it difficult to control the temperature throughout the plane and throughout the flight?
“We try to keep things close to 70 degrees, but it can be difficult,” says Patrick Smith, a pilot with a major US airline and author of the book. The cockpit is private. Keeping the temperature consistent throughout the aircraft is a challenge, he says.
A lot comes down to how the cabin temperature is regulated. “Often the cabin is divided into zones, each with its own controller,” says Smith. These controllers are similar to a home thermostat panel. “Temperatures can sometimes vary quite a bit, from zone to zone,” Smith said.
On some planes, especially older models like the Boeing 767, Smith says the heating and cooling systems are controlled by the pilots, with separate settings for each cabin zone: typically the cockpit, forward cabin (front of the plane), and aft cabin (back).
On other types of aircraft, the thermostat is controlled by flight attendants. But regardless of who controls the dial, having multiple zones means the climate can change depending on where you sit. This may help explain why, as Smith reports, “We get as many complaints about the cabin being too hot as we do about it being too cold.”
And there is another reason for temperature changes that travelers often experience. According to a pilot source, the deep freezing sensation that sets in about 20 minutes into the flight is actually a reaction to the hot and stuffy conditions you experienced before takeoff.
He explains that when the plane is at the gate it is cooled from an external air source, usually an AC unit located under the jet bridge. Once the engine starts and the aircraft begins to ventilate, pilots will “tweak the aircraft to cool down” to compensate. But often they don’t know how cold it’s gotten until they get a call from flight attendants.
Newer jetliners may have more sophisticated systems. For example, the Airbus A350, one of the European manufacturer’s latest wide bodies, has no less than seven different climate zones.
According to the Spanish carrier IberiaAdvanced technology allows for “more precise control” of temperature during flight, thanks to “sensors throughout the aircraft that measure the air as it comes out of the vents (to) help us identify and fix any potential problems.”
Why flight crews might like it cold
But regardless of the plane you’re on, passengers are still at the mercy of the flight crew who ultimately control the settings. And crews often prefer a cooler cabin, according to a flight attendant at a major U.S. airline who requested anonymity.
Those crew members noted that flight attendants who wear layered uniforms and are constantly on the move require more AC than passengers who wear light clothing and sit in their seats for hours. It’s not just a matter of crew convenience. In cases of severe turbulence, a cooler cabin can help ease passenger discomfort.
Ultimately, though, it comes down to the individual. “We’re telling passengers they’re too hot, and someone on the same plane is asking us to bring out blankets,” the flight attendant said.
And about those blankets: Starting about 15 years ago, most US airlines stopped handing them out for free. You can certainly buy one, but some customers can’t shell out the money if they’re shivering because of the airline’s frigid air. inside An infamous caseA Hawaiian Airlines transpacific flight had to be diverted after a passenger who complained about a cold cabin became angry when a flight attendant offered to sell him a $12 blanket.
Until the FAA steps in, the best course of action is to turn off the overhead vent and pull out the sweater you packed in your carry-on—even for a flight in August.