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My heart goes out to the 228 ppl onboard. very sad indeed...
The Pilots' View on Air France 447
It’s now clear that something horrendous befell the Air France flight from Brazil as military crews reported finding a fuel slick and metal debris roughly 400 miles northeast of the tiny island the flight passed on its way across the Atlantic. The case will likely turn out to be one of those most difficult aviation mysteries: recovery work in deep seas, no witnesses and no emergency calls from the crew. For those terrified to fly, Flight 447 is the kind of tragedy that confirms their worst fears.
At the moment, various “experts” conjecture that lightning and severe weather played roles in this incident, since the Airbus A330 transmitted nearly a dozen automatic status updates to Air France indicating electrical, pressurization and other systems problems. Those could prove helpful in figuring out what the plane experienced before it disappeared. Thunderstorms were noted just north of the equator at the time, in the so-called Intertropical Convergence Zone (ITCZ), the low-pressure area where warm hemispheric winds meet and rise and tend to spawn strong, high-altitude storms. (There’s a striking NASA satellite photo of thunderstorms along this zone here. A commercial meteorology firm, Accuweather, released a report today on weather in the region at the time Flight 447 was passing. The forming storm had updrafts of up to 100 mph, with the line of weather stretching 400 miles east to west, according to the report.
Of course, as Brett Snyder noted today at his Cranky Flier blog, the Air France flight was not alone in the region, as another company plane had left from Sao Paulo for Paris, Iberia had an Airbus A340 en route to Madrid, and Lufthansa had a Boeing 747 bound for Frankfurt. All those flight crews were likely watching the same weather systems.
As I tend to do when it comes to understanding jets and the people who fly them, I called some pilots. One, Patrick Smith, is a first officer from suburban Boston who flies Boeing 767s frequently between Brazil and New York, including a flight back from Sao Paulo on June 2. (Smith is an online columnist and doesn't want his employer disclosed.) The other is Mike Saunders, an Airbus 319/320 captain with US Airways, who lives near Dallas. He’s a former regional pilot who flew turboprops around Texas and knows his thunderstorms.
“My hunch is that it wasn’t lightning by itself or extreme turbulence by itself but more a combination of those things,” Smith said. Saunders considers it highly unlikely that a lightning strike by itself would lead to a major flight event, since newer planes have so many wicks to discharge electricity, including more than 30 on the flight control surfaces of 319s and 320s. Given technology and the experience gained from decades of increasingly safe air travel, most modern aviation disasters now result from a sequence of events, rather than a single mishap.
“I fly through the ITCZ all the time and I would rather deal with the storms in that environment than with the kind of embedded storms we have around here” in the U.S., since they’re isolated and relatively simple to avoid, Smith says. Smart, skilled pilots don’t fly into thunderstorms: They’re easy to spot on radar for the most part, easy to avoid and wildly unpredictable if you do tangle with one. In the U.S., routing deviations for thunderstorms are common. Smith monitored three or four storms on the ten-hour flight to New York early Tuesday, including one that “had no precipitation and it didn’t show up on radar.” That meant a choppy ride for three or four minutes, but nothing noteworthy, he said. But it does illustrate the way intense weather can materialize quickly, especially in tropical zones.
Saunders also notes that if you’re caught in a storm at cruising altitude, where the air’s thin, the “buffer margin” on how much you can speed up and slow down narrows greatly. Current Airbus models are electronic wonders engineered to minimize the danger from human mistakes. They won’t fly faster than design specifications allow and they don’t let themselves stall. But an electronic problem could grow to a point where the computers could be disabled or given incorrect data. Without trying to condense Saunders’ technical explanation of stall speeds and engine thrust into a big inaccurate mess, suffice it to say that flying one’s way out of a severe storm at 35,000 feet is far trickier than one can imagine. A violent interaction of lightning, updrafting winds, and hail could produce a very ugly environment for an airplane. Still, a third pilot I know, who also flies "heavy" airplanes like the A330 (but declined to be identified) considers any storm theory lacking given all the pressures current models are able to withstand in load tests.
“The Airbus … has something like 400 computers on it, to monitor everything,” Saunders says. “It won’t let the toilets flush at the same time, for example.” Hopefully, all that monitoring capability will give the families of the 228 people on board some insights into what happened.
The Pilots' View on Air France 447
It’s now clear that something horrendous befell the Air France flight from Brazil as military crews reported finding a fuel slick and metal debris roughly 400 miles northeast of the tiny island the flight passed on its way across the Atlantic. The case will likely turn out to be one of those most difficult aviation mysteries: recovery work in deep seas, no witnesses and no emergency calls from the crew. For those terrified to fly, Flight 447 is the kind of tragedy that confirms their worst fears.
At the moment, various “experts” conjecture that lightning and severe weather played roles in this incident, since the Airbus A330 transmitted nearly a dozen automatic status updates to Air France indicating electrical, pressurization and other systems problems. Those could prove helpful in figuring out what the plane experienced before it disappeared. Thunderstorms were noted just north of the equator at the time, in the so-called Intertropical Convergence Zone (ITCZ), the low-pressure area where warm hemispheric winds meet and rise and tend to spawn strong, high-altitude storms. (There’s a striking NASA satellite photo of thunderstorms along this zone here. A commercial meteorology firm, Accuweather, released a report today on weather in the region at the time Flight 447 was passing. The forming storm had updrafts of up to 100 mph, with the line of weather stretching 400 miles east to west, according to the report.
Of course, as Brett Snyder noted today at his Cranky Flier blog, the Air France flight was not alone in the region, as another company plane had left from Sao Paulo for Paris, Iberia had an Airbus A340 en route to Madrid, and Lufthansa had a Boeing 747 bound for Frankfurt. All those flight crews were likely watching the same weather systems.
As I tend to do when it comes to understanding jets and the people who fly them, I called some pilots. One, Patrick Smith, is a first officer from suburban Boston who flies Boeing 767s frequently between Brazil and New York, including a flight back from Sao Paulo on June 2. (Smith is an online columnist and doesn't want his employer disclosed.) The other is Mike Saunders, an Airbus 319/320 captain with US Airways, who lives near Dallas. He’s a former regional pilot who flew turboprops around Texas and knows his thunderstorms.
“My hunch is that it wasn’t lightning by itself or extreme turbulence by itself but more a combination of those things,” Smith said. Saunders considers it highly unlikely that a lightning strike by itself would lead to a major flight event, since newer planes have so many wicks to discharge electricity, including more than 30 on the flight control surfaces of 319s and 320s. Given technology and the experience gained from decades of increasingly safe air travel, most modern aviation disasters now result from a sequence of events, rather than a single mishap.
“I fly through the ITCZ all the time and I would rather deal with the storms in that environment than with the kind of embedded storms we have around here” in the U.S., since they’re isolated and relatively simple to avoid, Smith says. Smart, skilled pilots don’t fly into thunderstorms: They’re easy to spot on radar for the most part, easy to avoid and wildly unpredictable if you do tangle with one. In the U.S., routing deviations for thunderstorms are common. Smith monitored three or four storms on the ten-hour flight to New York early Tuesday, including one that “had no precipitation and it didn’t show up on radar.” That meant a choppy ride for three or four minutes, but nothing noteworthy, he said. But it does illustrate the way intense weather can materialize quickly, especially in tropical zones.
Saunders also notes that if you’re caught in a storm at cruising altitude, where the air’s thin, the “buffer margin” on how much you can speed up and slow down narrows greatly. Current Airbus models are electronic wonders engineered to minimize the danger from human mistakes. They won’t fly faster than design specifications allow and they don’t let themselves stall. But an electronic problem could grow to a point where the computers could be disabled or given incorrect data. Without trying to condense Saunders’ technical explanation of stall speeds and engine thrust into a big inaccurate mess, suffice it to say that flying one’s way out of a severe storm at 35,000 feet is far trickier than one can imagine. A violent interaction of lightning, updrafting winds, and hail could produce a very ugly environment for an airplane. Still, a third pilot I know, who also flies "heavy" airplanes like the A330 (but declined to be identified) considers any storm theory lacking given all the pressures current models are able to withstand in load tests.
“The Airbus … has something like 400 computers on it, to monitor everything,” Saunders says. “It won’t let the toilets flush at the same time, for example.” Hopefully, all that monitoring capability will give the families of the 228 people on board some insights into what happened.
. Hope the lost are found soon
.
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