Earlier this year, sixteen passengers and four crew members were injured on United, Cathay Pacific and Sunwing airlines’ flights due to the flights experiencing severe turbulence. Just last week, five passengers and two flight attendants were injured from severe turbulence on their US Airways flight.

From 2010 through 2013, 75 passengers and 74 flight crew members were injured on US domestic and international flights due to turbulence. According to the Federal Aviation Administration (FAA), turbulence is the number one cause of injuries to passengers and flight attendants in nonfatal accidents. Two-thirds of those injuries occur above 30,000 feet, while passengers are permitted out of their seats to move about the cabin.

On May 4th, US Airways flight 735, still climbing from its takeoff from Philadelphia International Airport (PHL), encountered unexpected severe turbulence as it passed through 17,000 feet on its way to cruising altitude.

Venus Desue said, “Twenty minutes into the flight, all of a sudden, we just felt this boom. And the plane felt like it dropped 20 feet down. Shoes were flying. Cell phones were flying. People were screaming. And it was very, very, very scary.” Passenger Mark Pensiero said other passengers told him a woman hit the top of the aircraft, her feet at their eye level.

US Airways stated that at the time of the incident on flight 735 the seat belts signs were on.

Of the 265 passengers and crew of ten on board the flight, five passengers and two flight attendants were taken to Philadelphia hospitals for treatment after the plane returned to PHL.

When I heard about the incident, I was greatly surprised that the plane was still in the midst of its climb to cruising altitude after takeoff and even more so when US Airways confirmed the seatbelt light was still on, telling passengers to remain seated with their seatbelts securely fastened.

The FAA and the airlines cooperate in their attempt to have flights avoid air turbulence to the extent possible, but unfortunately it’s not always possible to avoid severe turbulence while flying. That’s why seatbelt use and common sense are so important for airplane passengers.

The single most important safety device installed on modern airplanes is the passenger seatbelt, but only if passengers actually use them. Its design is, in large part, to prevent passenger injuries from problems such as severe air turbulence. It’s hard to image any passengers would have been throw from their seats, or hit their heads on the cabin ceiling, if they had been wearing their seatbelts securely tightened.

Air travelers should always wear their seatbelts securely tightened whenever they are seated. I know I do. It’s the best way to prevent injury when turbulence hits a plane.

It’s also hard to believe that shoes and cellphones and other objects would have been flying around the cabin if they were properly stowed as requested by the flight attendants.

Every passenger should follow commonsense procedures of stowing all loose objects, shoes, cellphones, tablets, books, etc., in their carry-on luggage, the seat back pocket, or under the seat in front of them for the duration of the flight. It can literally prevent passenger injury.

On every airplane flight, approximately every third passenger gets caught in the “middle seat squeeze” in the economy section. I know I’ve been caught in it. Seat mates regularly don’t quite fit into their window and aisle seats and take extra space from the middle of the row, where the poor guy there is “squeezed.” Not only that, but much of the time, the middle seater loses the use of their armrests, making the “squeeze” worse.

To help the hapless middle seat passenger, Paperclip Design, located in Hong Kong, has proposed a radical new armrest design, meant to ensure middle seat passengers won’t be denied the use of the two armrests on each side of their seat.

The Paperclip armrest looks like part of a paperclip, and via its ingenious design is really two armrests in one; one high and one low. On the surface the design looks promising, but a closer, more detailed examination reveals important flaws in the design.

Examining the design carefully reveals the bottom armrest is 8” (20cm) and the upper armrest is about 11” (28cm) above the seat. The height of the upper armrest is particularly problematic, especially for passengers having a height of 5’7″ (170cm) or less.

Cornell Ergonomics states that armrests should be no more than 10” above the seat. That inch (2.5cm) for short people will push their shoulders up into an extremely uncomfortable position for many. They won’t be able to use the upper armrest.

Passengers can adjust their height down, to a degree, by slouching to use an armrest which is a bit too low, but no one can adjust their height up, and that’s a major problem with this armrest. In addition, short people who have to use the forward section of the armrest will likely not be able to sit back in their seat comfortably.

Before they consider switching their armrests to the Paperclip design, I hope the airlines carefully examine its downside, including as a catchall for carry-on bag straps.

In the meantime, if squeezed in the middle seat, speak to your seat mates to get them to allow you the use the middle arm rests, as they have armrests only for them, plus the window and the aisle. That works for me when I’ve been caught in a middle seat.