20 Injured in SAA Turbulence incident: Global warming causing worse turbulence

Turbulence incident: Global warming causing worse turbulence ? 

Severe turbulence struck a South African Airways plane that was heading to Hong Kong, injuring 20 people before the aircraft landed safely on Wednesday, the airline said.

Medics were waiting at the Hong Kong airport to assist passengers on SA286, which had departed Johannesburg on Tuesday, the airline said in a statement.

Television footage showed rescue workers wheeling one injured passenger on a stretcher.

Three crewmembers and 17 passengers were injured, airline spokesman Tlali Tlali said.

The Hong Kong fire department said two people were critically injured. The victims were taken to three hospitals.

SAA Airbus 340-300

The airline said 165 passengers were on the Airbus 340-300 when the turbulence hit the aircraft as it flew over Kuala Lumpur, the Malaysian capital

Last year in a similar incident about two dozen people on two flights were injured when their aircraft hit turbulence before landing at Hong Kong's airport.

Thai Airways said 20 people were hurt when an Airbus A38-800 carrying 500 passengers, two pilots and 24 cabin crew from Bangkok encountered "unforeseen turbulence" as it was descending to Hong Kong's airport.

The airline said passengers and cabin crew suffered injuries but the plane landed safely. 39 were reported injured but the airline later revised the number to 20. Kung says the injured were sent to three hospitals in the southern Chinese city.

Hong Kong Airlines reported three passengers and three flight attendants were hurt when their flight from Phuket hit "sudden turbulence" as it neared the city's airport. The airline said the plane landed safely and the six have left hospital. The plane was carrying 110 passengers and seven crew.

Clear air turbulence:

The most insidious kind of turbulence, clear-air turbulence, is invisible, comes without warning and occurs any time during a flight. One of the main culprits of clear-air turbulence is the boundary between the jet stream—that aerial river that forms where arctic air masses meet warmer air from the south—and the slower-moving air adjacent to it. This invisible boundary shifts unpredictably, and woe to any unstrapped passenger in a jet that crosses it. "If you're flying in clear air, you have no indication at all. If an aircraft has passed through the area ahead of your airplane, your pilot might get an advance warning of turbulence ahead. "But if you're an early morning flight and you're going through an area first, you're going to be 'Probe One.'" 

Even the worst turbulence is no cause for alarm—by itself. I don't think an airplane has ever broken up in flight because of turbulence. All planes are built to withstand much more than even a severe turbulent event."

Which makes passenger safety when an airplane hits turbulence—especially without warning—primarily the responsibility of the passengers themselves. That means buckling your seat belt, just as the pilots and stewardesses recommend, anytime you're seated. Air travelers should not get complacent. The best thing to do is to not loiter around in the aisles of the airplane," he says. "Do what you need to do, then get back to your seat and put on your seatbelt. You're still hurdling through the air at 500 miles an hour; things can happen. in 2005 an Air Korea jet fell 100 m in clear air turbulence, causing significant injury. Passengers and objects effectively become airborne, and go into free-fall until they hit something.

There has also been an unprecedented increase in turbulence involving aircraft in Australia.

The Australian Transport Safety Bureau said turbulence doubled over the three-month period between October to December 2013, compared to the previous three months, significantly above the five year historical average.

Turbulence is the leading cause of in-flight injuries and an increase directly affects the safety of cabin passengers.

But the ATSB could not speculate as to why it was happening, according to Dr Stuart Godley head of the ATSB's Aviation Research Team.

"During the last five years there has been an increase in reporting, particularly from cabin crew, about an increase in turbulence, but we don't know why this is occurring," he said.

"Because they are weather-related, these events are cyclical.

"We're used to seeing more of them in summer, but this increase is unprecedented."

Turbulence is caused by the irregular movement of air and often cannot be seen.

When air masses with different speeds, direction or temperatures meet each other, turbulence is likely to occur.

While turbulence is normal and occurs frequently, it can be dangerous - especially for passengers not wearing seat belts or carrying unsecured items.

That was the case for one passenger in November 2013 who sustained a serious head injury from a laptop computer that fell from an overhead locker during a turbulent flight to Sydney.

Another passenger was injured after being struck by an iPad. Passengers not wearing seat belts are more likely to be seriously injured when turbulence hits.

"Serious head injuries can be sustained when a person hits the overhead panel where luggage is stored because they did not wear a seat belt," he said.

"Cabin crew have had legs broken from walking around the cabin when turbulence hit," he said.

Clear air turbulence (CAT) can pose a great amount of danger as it cannot be detected and hit any time, which is exactly what happened when cabin crew were commencing a meal service during a flight from Cairns to Tokyo in 1996.

Passengers, crew and meal trolleys hit the ceiling of the aircraft and landed heavily, seriously injuring passengers who were not belted up. Bone fractures, lacerations, neck and back strains, dislocated shoulders and shattered teeth were reported. Four were admitted to hospital.

While nothing that extreme has been reported during the recent bout of increased turbulence, Godley warns passengers to keep their seat belts on in the off-chance it should happen. Some areas of Australia are more prone to turbulence and Sydney has been a common spot for it to occur over the last summer, Godley said. "122 incidences of turbulence were recorded, 35 of which occurred on flights in to and out of Sydney, which seems to be a hot-spot for turbulence," he said. "Brisbane and the Gold Coast is another area which experiences a high amount."

Global warming to blame?

New research has found global warming is likely to double the chances of plane turbulence in the coming decades.

According to a study from the University of Reading and the University of East Anglia, atmospheric changes could lead to the amount of turbulent air patterns that affect planes doubling, and for the intensity to get stronger by the middle of this century.

Dr Paul Williams, who headed the research, said global warming would have a significant impact on the aviation industry. "Air turbulence does more than just interrupt the service of in-flight drinks. It injures hundreds of passengers and aircrew every year - sometimes fatally.

"It also causes delays and damages planes. The total cost to society is about US$150 million (NZ$177 million) each year." Researchers used supercomputer simulations to analyse jet streams over the North Atlantic Ocean.

Dr Manoj Joshi, from East Anglia, said they focused on looking at turbulence in its peak periods. "Our research focused on clear-air turbulence in winter. This is especially problematic to airliners, because clear-air turbulence is invisible to pilots and satellites, and winter is when it peaks."

It found the chances of encountering significant turbulence would increase by between 40 per cent and 170 per cent, but most likely double, and the intensity by anywhere between 10 and 40 per cent.

Williams said any increase in turbulence would make flying more uncomfortable and increase the risk to passengers and crew. Airlines would also be forced to re-rout some flights to avoid stronger patches of turbulence, which would lead to greater fuel consumption and emissions of atmospheric pollutants, make delays at airports more common, and ultimately push up ticket prices.

The research showed the atmosphere was becoming more vulnerable and unstable, and Williams said the aviation industry was partly to blame for that.

What is turbulence ? Turbulence explained in a previous blog (click link)

Turbulence ahead: Global warming to increase the bumpy rides

Turbulence ahead

Is global warming gonna give us a bumpy ride?

Fairfax News Reports: New research has found global warming is likely to double the chances of plane turbulence in the coming decades.

According to a study from the University of Reading and the University of East Anglia, atmospheric changes could lead to the amount of turbulent air patterns that affect planes doubling, and for the intensity to get stronger by the middle of this century.

Dr Paul Williams, who headed the research, said global warming would have a significant impact on the aviation industry.

"Air turbulence does more than just interrupt the service of in-flight drinks. It injures hundreds of passengers and aircrew every year - sometimes fatally.

"It also causes delays and damages planes. The total cost to society is about US$150 million (NZ$177 million) each year."

Researchers used supercomputer simulations to analyse jet streams over the North Atlantic Ocean.

Dr Manoj Joshi, from East Anglia, said they focused on looking at turbulence in its peak periods.

"Our research focused on clear-air turbulence in winter. This is especially problematic to airliners, because clear-air turbulence is invisible to pilots and satellites, and winter is when it peaks."

It found the chances of encountering significant turbulence would increase by between 40 per cent and 170 per cent, but most likely double, and the intensity by anywhere between 10 and 40 per cent.

Williams said any increase in turbulence would make flying more uncomfortable and increase the risk to passengers and crew.

He said airlines would also be forced to re-rout some flights to avoid stronger patches of turbulence, which would lead to greater fuel consumption and emissions of atmospheric pollutants, make delays at airports more common, and ultimately push up ticket prices.

The research showed the atmosphere was becoming more vulnerable and unstable, and Williams said the aviation industry was partly to blame for that.

NZ Perspective: I hold appointment to the Civil Aviation Authority of NZ as Departmental Medical Practitioner. (Health and Safety) All NZ registered flights and flight crews report significant injuries to the CAA. I am not aware of any fatalities of crew and passengers attributable to air turbulence. The last attributable commercial air crash worldwide was in 1966:

Commercial air traffic, in terms of turbulence, is pretty darn safe
The last crash caused by turbulence was  in 1966 near Mount Fuji in Japan.

In 2010, the US National Highway Traffic Safety Administration reported 9,442,000 car accidents, including more than 22,000 fatalities and almost 2 million injuries. The same year, the National Transportation Safety Board (NTSB) documented one major accident and 14 injuries on commercial planes, and no fatalities.

But don't be so quick to unbuckle your seat belt and freely roam the cabin. Turbulence is the No. 1 cause of in-flight injuries, with crew members often suffering the highest number of bangs, bruises and broken bones. The FAA reported that turbulence injured five passengers and 28 crew members last year. Over the same period, the NTSB investigated 10 turbulence-related accidents.

If people followed the rules the statistics would be even lower: Protecting yourself is as easy as insert, click, adjust. Even when the pilot turns off the sign, keep your seat belt on. If the plane suddenly jolts, you don't want to bump heads with the ceiling.

Also see my post: Turbulence 101: Turbulence for Dummies

Turbulence ahead: Turbulence 101

Turbulence 101 or "Turbulence for Dummies"

Useful information for fearful flyers

Jet wake or wash turbulence

On a recent flight to New Orleans, our 65-seat plane was gliding through the sky as smoothly as a swan on an unruffled lake. Then it hit a bump. And another.

A soda on a tray sloshed in its cup. The aircraft dipped, pitched and dropped several feet. A couple calmly set down their sandwiches and locked hands.

The flight attendant suspended beverage service and strapped herself into her seat. I looked out the window, at the clear blue sky and the bunny-tail clouds, and cursed the diabolical force that I could feel but not see.

When planes hit turbulence, we often start to despair and think the worst. Falling to the ground like a disabled bird, for example. But experts tell us to banish those doomsday thoughts.

"Planes don't come crashing out of the sky," said Patrick Smith, a pilot with 20 years of experience. (One exception: If you're Denzel Washington playing a tortured soul who turns a plane upside down to stop its dive in the new film Flight.)

Brian Tillotson, a senior technical fellow at Boeing, once comforted a nervous flier with this warm biscuit of wisdom: "This plane is designed to survive a crash, and this is nothing." He recommends that timid travellers adopt his mantra as their own high-altitude om.

Despite the hard facts and the placating statements, turbulence can rattle even fliers with nerves of reinforced steel. Two main factors weaken our resolve like kryptonite: our lack of control and our limited understanding of atmospheric conditions and airplane mechanics.

"Turbulence is far and away the number one concern of fearful fliers," said Smith, who hosts the website Ask the Pilot. "If I get 10 letters from nervous fliers, nine of them are questions about rough air."

Instead of staying in the dark, where things go bump in the cabin, I turned to scientific and airline industry experts and asked them to demystify turbulence and describe any advances in the art of its detection and avoidance. Armed with this knowledge, we can sprout wings of confidence that will carry us gently through the rough spots.

TURBULENCE 101

Class, pull out your e-notebooks for Turbulence 101.

By simple definition, turbulence is a disturbance in the regular flow of air. (Experts often use water as an analogy, such as an eddy on a river or a fish in the waves.)

The agitated air moves up or down or sideways, putting pressure on the plane's wings.


The vessel responds by pitching like a rodeo bronco or bouncing like a pogo stick. A plane, however, is not easily bullied by rogue air. It's built to resist. (For visual proof, check out the YouTube video of Boeing testing the wing strength of the 787.)

"On a roller coaster, everyone is screaming for joy," said Larry Cornman, a physicist at the National Center for Atmospheric Research in Boulder, Colo. "In an aluminium tube 30,000 feet in the air, it's the same principle, but you have no control."

Atmospheric chop is not monolithic but divided into subgroups with distinct characteristics.

Clear-air turbulence is caused by variations in the jet stream. It ramps up in winter, when the jet stream - zippy air currents in the Earth's atmosphere - migrates south, and often plagues flight paths over the Pacific.

Convective turbulence is created by thunderstorms and often occurs in the summer, when rumbling storms dominate the weather forecasts. Low-level turbulence is associated with strong winds, terrain and buildings, while wake vortex turbulence results from a lift as strong as a tornado.

Finally, if you've ever flown over the Rockies and landed at Denver's international airport, you've probably witnessed your cup of coffee shimmy and shake. The culprit: mountain wave turbulence.

"Turbulence is normal. It's part of the sky," said Smith. "It's not about the plane but where the plane is."

Turbulence follows a rating system similar to that of a spice-o-meter at an Indian restaurant - light, moderate, severe and extreme.

Cornman describes the stages, from mild to serious, as water rippling in a glass, liquid flowing out of the vessel and the cup flying through the air. Most passengers experience the swirling and spilling phases, but never the most intense situations, which can cause injuries and structural damage.

When a weather system threatens such peril, pilots do their utmost to avoid the roiling air. If stuck in an ugly patch, they will attempt to steer the plane toward calmer air, climbing to a higher altitude or changing course.

Pilots rely on numerous systems to track turbulence, including weather forecasts, radar, communication with air traffic control and updates from other planes in the vicinity.

"In general, we have a reasonably good idea of where the rough air is," said Smith. "But it can be more of an art than a science."

PINNING DOWN TURBULENCES

To help take the guesswork out of the pin-the-tail-on-the-turbulence game, physicists and other industry specialists are working on innovations that detect unsettled air.

For instance, Boeing installed the Vertical Gust Suppression System in the new 787 Dreamliner. VGSS acts like a super-beagle: Sensors in the plane's nose detect volatile air, then relay the message to the aircraft's brain, which automatically makes adjustments to reduce the bump. Passengers will probably sleep right through the tweak.

In May, the company received a patent on another invention, a GPS unit that can read the "twinkle" of the radio waves for more than 200 miles, thereby identifying erratic air flow. (Quick debriefing: Stars appear to twinkle when upset air bends and bobbles the light as it travels through the atmosphere; same deal with radio waves. Apologies for crushing the fantasy of stargazers who thought that little aliens living on stars were flicking their bedroom lights on and off.) At this early stage, no planes are equipped with the GPS unit.

Cornman, who was instrumental in the GPS program, is also tackling the turbulence issue at the federally funded center. Under the sponsorship of the Federal Aviation Administration (FAA), he and collegues developed the In Situ Turbulence Reporting Program, detection software that allows participating airlines (Delta, United and Southwest so far) to share reports on rough air.

Also in his bag of new tricks: radar software that can track "stuff embedded in the air," a useful tool for recognizing convective turbulence, and "lidar," lasers that detect small particles in visibly clear air and measure their motion. Delta uses the new radar capability, and the Hong Kong airport has installed the uber-lasers. Researchers are also throwing some brain cells at improving weather forecasting, which could inform pilots of upcoming chop.

"Turbulence is pretty dynamic," he said. "Pinning it down is pretty hard."

BELIEVE THE NUMBERS

If you're a nervous passenger, you've most likely heard this one before: Flying is safer than driving.

Don't argue with the prophet, because it's true.

"Commercial air traffic, in terms of turbulence, is pretty darn safe," said Cornman. As evidence, he cited the last crash caused by turbulence - in 1966 near Mount Fuji in Japan.

In 2010, the National Highway Traffic Safety Administration reported 9,442,000 car accidents, including more than 22,000 fatalities and almost 2 million injuries. The same year, the National Transportation Safety Board (NTSB) documented one major accident and 14 injuries on commercial planes, and no fatalities.

But don't be so quick to unbuckle your seatbelt and freely roam the cabin. Turbulence is the No. 1 cause of in-flight injuries, with crew members often suffering the highest number of bangs, bruises and broken bones. The FAA reported that turbulence injured five passengers and 28 crew members last year. Over the same period, the NTSB investigated 10 turbulence-related accidents.

"If people followed the rules," said Smith, "the statistics would be even lower."

Protecting yourself is as easy as insert, click, adjust. Even when the pilot turns off the sign, keep your seatbelt on. If the plane suddenly jolts, you don't want to bump heads with the ceiling.

You can also reduce the intensity of turbulence with a little planning. Larger jets provide more stability than smaller planes. For example, in the same wily patch of air, a passenger in a 747 might feel a mild bounce, while a traveler in a six-seat Cessna might complain of moderate bumps. Also, choose a seat in the middle rows, over the wings, instead of in the front or back of the cabin.

"Imagine a soda straw. Hold it in the middle and see how it flops," explained Tillotson of the phenomenon. "Air pushes on the wing. The nose and tail bounce."

Most important, remember that the rockiness will pass. With this as your mantra, sit back and enjoy the short ride on the atmosphere's waves.

"Instead of the seatbelt sign," said Cornman, "the pilot should turn on the 'wheee!' sign."

I'll throw up my hands to that.