Why don't airplanes have shoulder seat belts like cars?

Main Takeaways

When the "fasten seat belt" sign lights up in airplanes, accompanied by that familiar ding, passengers often react with a mix of annoyance and resignation, if they react at all. It's like, 'Really? Again? Do I really have to ...?'

The answer, naturally, is yes. You do have to. As mom would put it, "it's for your own good."

Richard McSpadden, executive director of the Aircraft Owners and Pilots Association's Air Safety Institute, attributes the typical flyer’s attitude toward seat belts to a mentality of, "It won't happen to me." "Aviation accidents are rare, so people think, 'What are the chances it’ll happen to me?' And I'd agree that the odds are very low," he says.

However, McSpadden adds, "Even though the odds are low, the consequences of something happening can be severe. Even a small bump in turbulence could cause your head to hit the top of the airplane. That can lead to serious injuries [see Now That's Interesting, below]. And strapping in is so simple." (For most people, anyway.)

A basic lap belt — or even other restraints like shoulder harnesses — might not be enough to save you if an airliner falls from 35,000 feet (10,668 meters) or experiences a catastrophic mid-air failure. A seat belt wasn’t sufficient in the tragic case of Jennifer Riordan, who was reportedly wearing her seat belt when a piece from a failed engine on a Southwest Airlines 737 shattered the window next to her seat on April 17, 2018. The sudden rush of air nearly sucked her out of the airplane.

Seat belts on airplanes aren't just for rare accidents like crashes or the more common situation where the plane hits the ground. They're also crucial for keeping you safely secured inside the aircraft during flight.

The Case for Seat Belts

"The reason you must wear a seat belt, flight crew included," Heather Poole, a flight attendant with American Airlines and author, explained to The Telegraph in 2015, "is because you don’t want the plane to land on you. Many people believe they get lifted into the air during turbulence, but the truth is, the plane drops. It drops quickly and hard, and that’s when injuries occur — usually from being struck on the head by the airplane."

This is basic physics, Newton's first law of motion: An object at rest will stay at rest unless acted upon by an external force.

To put it another way: If you’re not wearing a seat belt on a plane that drops suddenly due to turbulence, you’ll remain in place while the plane descends rapidly. However, if you're buckled up, the seat belt acts as that external force, keeping you in sync with the plane and preventing you from slamming into the overhead compartment.

"It keeps you securely in place, moving with the airplane," McSpadden explains. "It's that extra safety cushion, ensuring that if something unforeseen occurs, you'll remain safely with the aircraft."

Are Shoulder Harnesses Better?

One could reason that if a lap belt is effective for flight, a shoulder harness — similar to those found in cars and smaller general aviation planes — should be even more protective. Indeed, experts like McFadden suggest that shoulder harnesses could offer additional safety benefits.

However, installing shoulder harnesses would be expensive and difficult to implement effectively on larger commercial aircraft, experts point out. Additionally, they might be uncomfortable for passengers on long-haul flights, and there may be resistance from the flying public to wearing them.

"The answer is yes, it would definitely help, as it would prevent the upper torso from moving abruptly in the event of a sudden impact," McSpadden says. "The challenge lies in how to implement this effectively."

Some question the necessity of shoulder belts on commercial airlines, given that lap belts — when used properly — seem to suffice. "Clearly for the vertical deceleration [typical] of an airplane crash, the lap belt seems to be the most important restraint," said David King, a trauma surgeon at Massachusetts General Hospital, told Time after the July 2013 Asiana Airlines Flight 214 crash in San Francisco that claimed three lives. (The official National Transportation Safety Board report on the incident noted: "The two ejected passengers (one of whom was later run over by two firefighting vehicles) were not wearing their seatbelts and would likely have remained in the cabin and survived if they had been wearing them.")

In smaller planes, however, shoulder harnesses — required in all small aircraft since Dec. 12, 1986 — are highly effective. When used alongside lap belts, these shoulder harnesses in smaller aircraft have been shown to reduce serious injuries from accidents by 88 percent and fatalities by 20 percent, according to the Federal Aviation Administration (FAA).

Ironically, the outstanding safety record of commercial airlines may be the main reason shoulder harnesses have not been mandated on large passenger planes. In 2017, there were no fatalities in any commercial jetliner incident worldwide, making it the safest year on record for large passenger aircraft. According to the Civil Aviation Safety Review for 2017, published by the Dutch aviation consulting firm To70, the rate of fatal accidents was "0.08 fatal accidents per million flights [in 2017]. That means one fatal accident for every 12 million flights."

With such a remarkable safety track record, it’s hard to argue that introducing shoulder harnesses would significantly reduce the risks of flying enough to justify the costs, effort, and opposition such a major change would create.

Lap belts, on the other hand, are effective. They're very effective. So, when flying, it’s best to fasten your seatbelt and keep it on for your own safety.