Monday, June 01, 2009

Air France 447

Depressing news:
President Nicolas Sarkozy of France said: “It’s a tragic accident. The chances of finding survivors are tiny.”
That's pretty strong language without knowing yet exactly what happened, but perhaps they are counting the negatives-
  • hit the thunderstorms at night and had some kind of electrical failure
  • the crew has yet to contact anyone, even with a satellite phone
  • has to be on earth somewhere based on fuel load
  • was over the open ocean when it last reported and has not been seen on land
  • was in the region without ATC radar or ground based weather radar
  • there has been no reported ELT distress signal, which does not report underwater
The Times story called the region the "Horse Latitudes", which is incorrect--they were closer to the "Doldrums", an area known for relatively calm winds that used to trap ancient mariners for weeks at a time waiting for wind. So maybe there's a slim hope that if seas were calm and they had any control the pilot pulled off another "Sully" landing and they're all stranded out in the open ocean. But surely someone would have used their satellite phone by now. Wonder, could these tools actually locate this aircraft and if so, would they admit it?

As to the weather influence, the "Inter-Tropical Convergence Zone" or "ITCZ" is well-known to any 11,000 hour pilot flying trans-Atlantic routes from South America. While there's no weather radar in the ocean pilots do have onboard radar and would have been vectoring around the cells. Most commercial carriers use a 20 mile clearance rule for thunderstorm avoidance but sometimes it's not possible, although they should have had plenty of room to deviate.

Onboard radar cannot detect turbulence, which can occur at any altitude near storms, but it's rarely responsible for causing much more than injuries to the cabin crew on large aircraft. Indeed, the Air France spokesman said:
“Lightning alone is not enough to explain the loss of this plane,” he said. “Turbulence alone isn’t enough to explain it. It is always a combination of factors.”
As to lightning, very few modern jets suffer much from a strike, even near the ground, due to the sophisticated arrester systems. On the other hand extreme turbulence can cause damage and loss of the aircraft, especially with smaller planes.

Extreme is one step up from severe and most pilots never report it because they're busy fighting to regain control and find a place to land after encountering it. American Flight 587, an A300, crashed due to wake turbulence off Long Island in November 2001 when the flying first officer overdid the rudder controls and ripped its tail fin off. Another Airbus lost its rudder during an encounter with turbulence off Cuba in 2005 but landed safely, so it's not out of the question.

Of course terrorism cannot be ruled out yet, either. When KSM testified at Gitmo he mentioned being responsible for the shoe bomber operation "on two American airplanes" although there was only one shoe bomber story in the news. Make of that what you will. The planes' disappearance could also be attributable to purely mechanical failure; a distraught pilot; or even unexplained natural phenomena, all speculation at this point.

Until we know, here's hoping--praying--for another miracle.

MORE 6/1/09

Here's the final transmission:
Those were the final signals from the plane. At the time, the Airbus was about 190 miles northeast of the Brazilian city of Natal, heading along its planned flight path toward the Cape Verde islands off West Africa, a course that should have brought it to Paris at 11:15 a.m., Air France said.
Is there information on the internet to show what the plane encountered weather-wise? Yes indeed, the Universtiy of Wisconsin CIMSS satellite blog.

Here's a link to their satellite loop of the region during the time in question:

For perspective, here's a Google Earth view of the region. Note the position 190 miles northeast of Natal, Brazil, which is the last known position according to the WaPo article. That would put it roughly around 3 degrees South, 33 degrees West.

Take a look at the corresponding satellite loop. A small storm popped up quick around 4 1/2 degrees south 33 degrees west about the time of passage. That would have been about half way between Natal and its final known position, around the small atoll called Fernando de Noronha, which reported clear weather at the time (verified by this picture). It would be shocking if the aircraft got anywhere near the large storms seen north of the Equator. Could perhaps a small but intense storm popping up out of nowhere have posed a greater threat than a line of storms visible from hundreds of miles away?

MORE 6/2/09

Some wreckage has been spotted in a position approximately 410 miles northeast of the last known contact, which would place it north of the equator about 0.5 degrees north, 28.5 degrees west. Here's the map:

Comparing it to the satellite weather loop would put the plane a lot closer to the more vigorous thunderstorms and their resulting hazards. That's a considerable distance from the last known location, though, which reports yesterday cited was when the automatic maintenance reports came in, indicating big trouble. It's hard to believe they could have flown another 400 miles, or that wreckage could have drifted that far north in 24 hours. Then again, we shouldn't trust the media to report locations correctly--see below.

Some are speculating they might have been struck by hail, which could not only flame out the engines but crack the windshield, perhaps causing a breakup of the airplane at flight level. That would explain a few things except why the pilots would have flown into such a thing at 35,000 feet--hail has a bright signature on radar. The black box would clear this up quickly, so it's a waiting game for now.

Meanwhile CNN has this curious comment (emphasis added):
Flight 447 was carrying 228 passengers and crew members from Rio de Janeiro to Paris, France. About three hours into the journey, more than 200 miles off Brazil's coast, the jet transmitted 10 maintenance reports: one for each piece of malfunctioning equipment, the professor said.

About 10 to 15 minutes later, when the Airbus A330 was scheduled to be over the Canary Islands -- where the radio would generally function better, because the plane is over land -- Flight 447 was expected to send a location report but didn't, Hansman said.
Considering the Canary Islands are about 2400 miles from a position 200 miles off the coast of Brazil the plane would have had to have been traveling between 9600 and 14,400 mph to make that in 10 to 15 minutes. Has CNN laid off all their editors?


Anonymous said...

So thick and dense are the concentrations of global warming becoming that they can down planes.

Impeach Bush, vote Obama, legalize drugs, free Manson.

Manu gomez said...

I still believe the plane crasehed somewhere near shore. the pilot flew back the troubled flight from the storm and crash landed somewhere near to fortlenza and natal. i have tried to say this in few sites.. but noone posted. atleast one search team should be send to these area near shore for the missing aircraft.. manugomez, kuwait

A.C. McCloud said...


They are finding bodies well out to sea. I think it broke up in turbulence and crashed close to the last known transmitted report.

As to the Drudge headline about there being two possible terrorists onboard, why weren't these guys on a watch list? It's all too convenient for Air France is they don't find the black boxes and it's left a mystery/possible terror attack.