Air France crash may show pilots can be overwhelmed by weather

12:23, 04 June 2009
World
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Even after decades of advances in technology

The crash of an Air France jet this week over a remote stretch of the Atlantic Ocean may show the limits of pilots’ ability to cope with severe weather even after decades of advances in technology, analysts said, Bloomberg reported.

The plane was traveling in an area that lacked coverage from ground-based radar, which controllers otherwise can use to help spot storms, said William Voss, head of the Flight Safety Foundation. With less than one flight an hour in the region, there also would have been few advance reports on conditions from other pilots, he said.

The possibility that storms may have contributed to the crash is an early focus of inquiry as authorities search for the “black box” voice and data recorders that would provide more detailed information of what happened on board. While weather causes fewer crashes than in the past because of advances in radar, pilots still depend on outside guidance to steer clear of dangerous squalls.

“No captain in his right mind would drill a modern airliner through a thunderstorm,” said Jack Casey, a former airline pilot and consultant at Safety Operating Systems LLC in Washington. “It’s just not done.”

The Airbus SAS A330-200, with 228 on board, appears to have flown into or near a large cluster of thunderstorms northeast of Fernando de Noronha, located off Brazil’s coast, according to AccuWeather.com.

Updrafts may have reached 100 mph, and the storms, stretching for over 400 miles (644 kilometers), towered as high as 50,000 feet, according to the weather service.

Quick-Forming Storms

It’s possible that a pilot could misinterpret information on cockpit radar or that a storm could form so quickly as to catch the crew by surprise, Casey said.

“The area of weather along that route of flight wasn’t even there when the aircraft was leaving the coast,” Voss said.

Also possible is that the pilot could have taken manual control of the airliner during turbulence and in the “heat of battle” might have manipulated controls, overloading the airframe and leading to the accident, Casey said.

“We’re all just kind of groping in the dark on this thing,” Casey said. “I don’t know what happened out there over the Atlantic. I’m scratching my head. There were big thunderstorms in the area. What’s new about that? Most accidents like this are an accumulation of little things.”

It’s too early to pin the cause of the crash solely on weather, said Larry Burch, deputy director of National Oceanic and Atmospheric Administration’s Aviation Weather Center in Kansas City, Missouri.

“Weather may be have been a contributing factor,” Burch said. “Whether it was the sole factor, no one knows.”

Around, Not Through

Passenger planes typically fly around, rather than through, storms, Burch said. Commercial planes are equipped to avoid storms with radar and other computer equipment, Burch said.

“That’s why part of me thinks there’s got to be some other reason that this happened,” he said. “There are thunderstorms really big that may be difficult to go around. If this particular plane was on a given course that he couldn’t go all the way around, that might have been something.”

Jim Hall, former chairman of the U.S. National Transportation Safety Board and now a partner with Nolan Law Group of Chicago, said “one of the things they are going to have to look at was what was the flight plan, and did they choose to continue through this area of activity because of reasons of fuel supply, or what the decision was.”

A Pulkovo Airlines flight crashed in the Ukraine in August 2006 after the pilot decided to try to climb over a storm, according to data posted on Flight Safety Foundation’s Aviation Safety Network Web site.

Human Error

The Ukraine thunderstorm network was unusually high, extending up to 49,000 feet, according to the Web site. The plane entered severe turbulence, the nose of the plane rose to 46 degrees and the aircraft entered a deep stall from which it didn’t recover, according to the Web site.

Russia’s Interstate Aviation Committee blamed the crash, which killed all 170 aboard the Russian Tupolev TU-154, on human error.

Because of technology advances, weather-related accidents are far less common than those caused by human error and mechanical failures, said Casey.

“Airborne radars today are phenomenal,” he said. “Technology has had a tremendous success.”

Even with weather radar, the updrafts that analysts say may have rocked the aircraft would have been difficult to pick up, said Voss, chief executive officer of the nonprofit Flight Safety Foundation, in Alexandria, Virginia.

“If you take a look at the satellite information online it was like an explosion of weather at the time the Air France flight would have been trying to pick its way through the Intertropical Convergence Zone,” he said.

Radar Coverage

U.S. radar coverage extends about 150 to 200 miles over the ocean, said Paul Takemoto, a spokesman for the U.S. Federal Aviation Administration. Beyond those zones, airline pilots stay in contact with air-traffic controllers, who lack the radar weather information the pilot can see in the cockpit, Takemoto said.

The FAA is working to expand satellite-based technology that would provide coverage over oceans, starting with the Gulf of Mexico, he said.

“We have a whole lot of instrumentation that provides additional information to the flight crews, in addition to what they have in the cockpit that has helped,” said Hall, the former NTSB chairman. Still, “weather has been and continues to be a factor” in aviation accidents.”

Bloomberg

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