First Published 1 June, but inadvertently deleted. It has been edited and re-posted today along with the accompanying comments. Thanx. Paul Miller
The Weather Channel displayed an inter-tropical convergence zone (ITCZ) satellite shot of the area at the time of AF447 passage through the area. The Sat shot showed large areas of high cloud tops. This suggests ongoing convective activity. Routine meteorological knowledge of the troposphere in the tropics places the trop layer at about FL600.
In laymen terms, the thunder-boomers were likely topping out at 60,000 feet. The coverage for the area looked as if a flight would have to pick its way though and might not be able to "stay on the track of the course."
If this metro estimation is relatively correct, the violent convection turbulence, hail, lightning and precipitation would make the transit of any cell or area of cells on this track or this course to be extremely hazardous.
Additionally, one other hazardous character of convection in the tropics is very rapid cell growth. Cells can grow at rates in excess of 6000 feet per minute. This means that a cell could literally grow right up in front of you in what may have appeared on radar to be a clear area. Pilots who fly to South America from various Miami airline domiciles can verify this amazing metro phenomenon when in the tropical inter convergence zone.
Three other safety things are troubling to me though: If the Weather Channel can have this data available for presentation to me, while I am sitting in my den in my house on my TV, why doesn't airline's flight control dispatch have this current data available for presentation to the flightcrew in the cockpit real time, while in flight? Remember that the preflight briefing occurred about 5 hours prior to the thunderstorm area transit, the transit was at night and this ITCZ is extremely dynamic both vertically and horizontally.
Why are Convective Sigments merely passed to flight crew, without flight control route hazard analysis, on the presumption that only the flight crew in flight, are to plot each weather report and compare it to the flight path to determine the hazard? Is not the company a stake holder in this issue? Should not flight control determine if the activity is in the flight's path and recommend the safest path around the severe convection?
Why isn't this done on the ground where more resources are available?
Next, does Air France have a procedure whereby flight crew are required to avoid convective cells by 20-30 miles? Do Air France flight crews actually comply with such a procedure? Is it a procedure or is it a policy? At your airline, is this avoidance a policy or a procedure?
Can an airborne radar with perhaps a good 80 mile range be expected to be sufficient equipment to circumnavigate an area 200 to 300 miles in width? Once in clouds, how capable is an airborne radar, in comparison to ground based hourly sat photos and infra red cloud top imaging?
Lastly, I suspect that there were other flights in the area at the time, heading to Europe and other points. What did they see in terms of weather? What did the official weather agencies report? Did any coordination transpire to assist the flight crews? Was there any chance of weather radar from Brazil being transmitted to flights in the area?
Let's see, Antoine De Saint Exupery wrote about this in his 1931 novel "Night Flight." ISBN 9780156656054
[Opps, I forgot, The Patagonian Weather services set up in the mid 1920's, may not have changed much. I wonder if the same guy may still be working there with a sandwich, thermos of coffee, pack of cigarettes and a sharp pencil.]
How many times have pilots heard some version of this statement? "It is not our job to advise pilots about what they are supposed to do. It is our job only to observe and report the weather, the cloud covering and rain."
Initially Posted by Paul Miller at 9:25 AM, June 1, 2009
Edited and re-posted 2 June.
