Severe air turbulence at 30,000 feet

If you’ve experienced it while flying, you know severe air turbulence can be frightening, jarring, jerky, and jolting, even for experienced air travelers. Turbulence can be extremely dangerous to both the flight crew and passengers alike.
Just last month, American Airlines flight 280, flying from Seoul, South Korea, to Dallas-Fort Worth International, with 240 passengers and a crew of 15 aboard, experienced severe turbulence. Less than an hour into the flight, they had to divert to Tokyo’s Narita International Airport. While no injury was life threatening, four passengers and one crew member were transported to hospitals for evaluation and treatment. Nine others were treated by medical personnel at Narita.
According to the FAA (Federal Aviation Administration), from 2002 through 2013 (last year reported) there were a total of 430 air crew members and passengers injured from turbulence on US air carriers.
Sometimes injuries from turbulence are severe.
In 2009, when a total of 75 crew members and passengers were injured by turbulence, a woman was paralyzed from the chest down after being thrown into the ceiling of her airplane’s lavatory during severe turbulence. The Continental Airlines Boeing 737 in which she was flying went into a sudden descent and rolled about 30 degrees.
In 2014, turbulence on United Airlines flight 1676 was so severe that one passenger cracked the plane’s ceiling panel with her head, and a baby was thrown into a nearby seat, unbelievably unharmed.
Most of the air turbulence we occasionally encounter while flying is neither severe nor dangerous, but passengers never know when severe “clear-air turbulence” (CAT) might occur. CAT is the turbulent movement of air masses in the absence of any visual clues (clouds, etc.) and is caused when bodies of air moving at vastly different speeds meet. Some people refer to CAT as “air pockets.”
When encountering CAT, the plane can quickly lose significant altitude, causing passengers and belongings to fly upward and around the cabin rapidly. The sudden movement can jar heavy bags in the overhead bins to fly out, crashing into passengers and crew.
Even less severe turbulence can cause injures. Hot beverages can be spilled onto passengers, causing burns.
In the article, “Intensification of winter transatlantic aviation turbulence in response to climate change,” published last April in the journal, “Nature Climate Change,” experts said turbulence might become more common due to global warming. The article reports that turbulence strength over the North Atlantic flight corridor could increase by 10 percent to 40 percent, and turbulence frequency could jump by 40 percent to 170 percent by the middle of the century.
From 1980 through 2008, US air carriers had 234 turbulence accidents, resulting in 298 serious injuries, including three fatalities. Generally two-thirds of all turbulence related accidents occur at or above 30,000 feet.

According to the FAA, at least two of the three fatalities involved passengers who weren’t wearing their seat belts while the seat belt sign was illuminated.

Before discussing the problem of severe air turbulence further, we need some perspective about it.
From 2002 through 2013, an average of 36 people per year were injured due to turbulence (half crew, half passengers) on US flights, while about 636M passengers or so flew in the US each year during that period.

That said, there is often no warning whatsoever that CAT is about to occur.

As passengers, what do we need to know, and what can we do to protect ourselves from the effects of severe air turbulence?
• Air passengers must realize turbulence is often unpredictable, and pilots don’t get much warning about it. No technology, including radar, can detect it at this time. At best, pilots have a general warning.
• While most turbulence encountered while flying is harmless, passengers should be prepared in case of severe air turbulence — especially CAT — which generally leaves little time, if any, for the flight crew to warn passengers.
• While pilots are trained to deal with severe air turbulence, passengers can still be gravely injured during its occurrence.
• Whenever you’re in your seat, always wear your seatbelt pulled snuggly against your body, even while sleeping, to keep yourself safer.
• Just as it’s virtually impossible to hold a baby or infant safely in your arms during a crash, the same is true during severe turbulence. Put your baby or infant into a car seat, properly strapped into the separate seat on the plane you purchased to keep them safe.
• Always obey the seatbelt sign in the plane. Contrary to popular myth, pilots don’t use it for sadistic purposes.
• Before leaving the gate, and after anyone opens the overhead bin over or across from you, be sure it’s been securely closed. During severe turbulence, it’s likely heavy bags will fly out of improperly closed bins.
There may be some technological help to avoid turbulence in the future. Since 2013, scientists at the DLR German Aerospace Centre have been testing an ultraviolet laser-based system to identify changes in the air indicating CAT ahead. Currently, their progress toward building a commercially available system is unknown.
(Image: Turbulence in US Airways A333, Envoy Class (Business Class) Cabin, Copyright © 2014 NSL Photography. All Rights Reserved.)