Post by Tom Goodrick on Jun 4, 2009 20:20:14 GMT -5
The Air France crash was a terrible trajedy, of course. At least 228 people died somewhere between cruise altitude and the ocean surface. We have discussed crashes before as a way of trying to understand the complexities of aviation that lead to crashes. We don't look to place any blame on a particular party. in this case I think a few facts are helpful for clarity because the news people have given us many mioxed up versions of the events with plenty of baseless speculation.
I just finished reading a well-written article in the New York Times about what is currently known. Here are some facts in genral order:
1) The pilot reported flying into a thunderstorm.
2) About 10 minutes later several automatic transmissions to satelites indicated major malfunctions consistent with mid-air break up.
3) A few more transmissions occured for about 4 minutes.
4) There was an oil slick indicating not all fuel was burned up in an explosion.
5) Air France has issued an advisory to all Airbus pilots to use the prescribed procedure to deal with inconsistant airspeed indications.
It is important to note that the simultaneous transmissions of mechanical malfunctions do not indicate potential problems to which the pilots have a chance to respond but rather a list of drammatic events that have already occurred in a brief interval at virtually the same time.
I have suspected a bomb as the most likely cause and that still remains the most likely cause simply because other explanations are very complex and less probable in today's international situation. But we don't have any strong indications of any particular cause. We may never get them. The pilot mentioned a thunderstorm. That does not mean it was the cause. But it certainly admits the possibility.
The automatic transmissions are the best indication that the aircraft came apart in the air and did not maintain its integrety until striking the water. These automatic devices have secure independent locations and transmitted their terse indications of events: Autopilot disengaged. Airspeed mismatch. Loss of cabin pressure.
The oil slick does not reduce the chance that a bomb caused this problem. On a large aircraft like this, a bomb that separates the portion of the fuselage ahead of the wings would leave plenty of fuel in the tanks to make an oil slick.
I think the warning about airspeed by Air France is pretty silly. It is simply an attempt by Air France to appear to be doing something positive in response. They might as well have said "Read Your Operating Manual." We think of an airspeed reading as some thing very basic and very simple. But if the aircraft is not flying steadily, it can be anything BUT simple. There are severl probes at which ram (or total) pressure is read. There are several orifices on the sides of the fuselage at which static pressure is measured. These measurements are made some distance from where the differences in these pressures is determined. The first assumption is that the little tubes that carry the pressure values do not get broken loose from connectors or plugged by rain. (There are loops in the lines to keep moisture from being a direct influence. But rain driven hard at the side of the fuselage or directly into the total pressure probes may cause problems.) If a fuselage were to spin and tumble, all readings would differ. Most portions of a nose broken loose from the main body will spin and tumble. In modern large aircraft, sensors in remote locations may transmit their data to processing units so a physical connection is not required.
To assume the pilots failed to manage airspeed properly is the silliest explanation of all.
The mixed up state of reporting on this topic is shown by the ad I saw at the top of this page when I finished writing and look up to proof read the final statement:
"Crashed Jet Was Defective
Defective Jet Was Permitted To Fly Watch this story!
www.russiatoday.com"
It seems some of our Russian friends can save us all months of detailed study by publishing such a conclusion. One wonders if they would be so quick if it were a Russian jet.
I just finished reading a well-written article in the New York Times about what is currently known. Here are some facts in genral order:
1) The pilot reported flying into a thunderstorm.
2) About 10 minutes later several automatic transmissions to satelites indicated major malfunctions consistent with mid-air break up.
3) A few more transmissions occured for about 4 minutes.
4) There was an oil slick indicating not all fuel was burned up in an explosion.
5) Air France has issued an advisory to all Airbus pilots to use the prescribed procedure to deal with inconsistant airspeed indications.
It is important to note that the simultaneous transmissions of mechanical malfunctions do not indicate potential problems to which the pilots have a chance to respond but rather a list of drammatic events that have already occurred in a brief interval at virtually the same time.
I have suspected a bomb as the most likely cause and that still remains the most likely cause simply because other explanations are very complex and less probable in today's international situation. But we don't have any strong indications of any particular cause. We may never get them. The pilot mentioned a thunderstorm. That does not mean it was the cause. But it certainly admits the possibility.
The automatic transmissions are the best indication that the aircraft came apart in the air and did not maintain its integrety until striking the water. These automatic devices have secure independent locations and transmitted their terse indications of events: Autopilot disengaged. Airspeed mismatch. Loss of cabin pressure.
The oil slick does not reduce the chance that a bomb caused this problem. On a large aircraft like this, a bomb that separates the portion of the fuselage ahead of the wings would leave plenty of fuel in the tanks to make an oil slick.
I think the warning about airspeed by Air France is pretty silly. It is simply an attempt by Air France to appear to be doing something positive in response. They might as well have said "Read Your Operating Manual." We think of an airspeed reading as some thing very basic and very simple. But if the aircraft is not flying steadily, it can be anything BUT simple. There are severl probes at which ram (or total) pressure is read. There are several orifices on the sides of the fuselage at which static pressure is measured. These measurements are made some distance from where the differences in these pressures is determined. The first assumption is that the little tubes that carry the pressure values do not get broken loose from connectors or plugged by rain. (There are loops in the lines to keep moisture from being a direct influence. But rain driven hard at the side of the fuselage or directly into the total pressure probes may cause problems.) If a fuselage were to spin and tumble, all readings would differ. Most portions of a nose broken loose from the main body will spin and tumble. In modern large aircraft, sensors in remote locations may transmit their data to processing units so a physical connection is not required.
To assume the pilots failed to manage airspeed properly is the silliest explanation of all.
The mixed up state of reporting on this topic is shown by the ad I saw at the top of this page when I finished writing and look up to proof read the final statement:
"Crashed Jet Was Defective
Defective Jet Was Permitted To Fly Watch this story!
www.russiatoday.com"
It seems some of our Russian friends can save us all months of detailed study by publishing such a conclusion. One wonders if they would be so quick if it were a Russian jet.
