Concerning fuel on board. Please read BEA's report appendix 7 page 116/117.
http://www.bea.aero/docspa/2009/f-cp...90601e1.en.pdf
At T/O, they had :
- 900 kg EXTRA fuel over the minimum M .82 DIRECT flight plan to CDG (alternate ORY) ;
- 1.900 kg EXTRA fuel over the minimum M .81 DIRECT flight plan to CDG (alternate ORY) ;
- 2.000 kg extra fuel over the minimum M .82 "
subject to RIF to CDG" ("ETF" in BEA's wording) flight plan to BOD (alternate TLS).
At any given time, if fuel becomes an issue, the crew can decide to fly at M .81 (iso M .82) or to land at LIS/BOD/NTE without too much "
embarrassment".
Concerning ITCZ crossing. Please read Tim Vasquez conclusion :
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data
Air France Flight 447 crossed through an area of tropical showers and/or weak thunderstorms with weak to moderate updrafts and a high likelihood of turbulence. The flight penetrated one cell at about 0150 UTC and then entered a cluster of cells beginning at 0158 UTC. The suspected zone of strongest cells was reached at 0208 UTC, which corresponds with the beginning of a track deviation, and another cell appeared to be reached at 0210 UTC, which corresponded with the time of autopilot disconnect. The flight was suspected to be within areas of showers and precipitation up until the time of impact, and the descent below FL250 into the critical -10 to -20 deg C zone probably involved some degree of clear icing on control surfaces, though it is uncertain whether this affected recovery of the aircraft, especially due to the short accumulation time that would be involved.
Tropical storm complexes identical to or stronger than this one have probably been crossed hundreds or thousands of times over the years by other flights without serious incident, including ascents and descents through critical icing zones in tropical showers. My original conclusion from June 2011 is still unchanged: turbulence and possibly icing creating an initial problem that led to a failure cascade. Whether that final weak link was human or machine error is beyond my area of expertise and is best left for the experts at BEA.
If CB/turbulence was a factor, why did they start to deviate at 02:08 and not during the 01:50/02:08 period (when they went through an equally "bad" area according to figure 5b shown above) ?
Concerning captain behavior : he went to rest only 10 minutes before things went bad.
Who on earth would go to rest if the 160 Nm radar picture showed some "extra-ordinary" weather ahead
