BOAC - Yes it's small; - the original argument, (
that the crew may not have felt that there was sufficient fuel, due to filing short of destination and later dropping "the alternate", such that diverting around weather was not possible and therefore did not), is moot; there is no basis for the argument, or the point, whatsoever.
A large deviation that would add perhaps 40nm/5minutes/500kg to the flight plan is a lot, given the "geometry" of such diversions done early, as you say. (Sometimes, (obviously), it is best to wait until closer in to ensure clear down-stream pathways and avoid cells attenuated/blanked by closer, larger cells). But the figures are indeed in the ballpark for the A330. For a ten hour flight it would not be unusual to board 1T of Wx Fuel for pos. diversion, on top of contingency, alternate and min.fuel.
I obviously can't comment on theoretical diversion-planning around the weather that AF447 and seven or eight other flights faced but a "larger slice" at a diversion, (longer distance) may have been considered given the relative proximity of cells and the length of the line.
But the evidence that the line was successfully negotiated, as are such ITCZ lines negotiated every day by many airliners, is evidence for the fact that it is done successfully all the time and fuel "emergencies" remain rare and therefore flight planning techniques are working as intended. Even at a full 1T of fuel, there was plenty of reserve fuel left to complete the flight to CDG without concern.
While not intending to draw any more attention to the Der Spiegel op-ed, one point is important to clarify regarding the captain. Der Spiegel states:
So far, it's unclear who was controlling the Air France plane in its final minutes. Was it the experienced flight captain, Dubois, or one of his two first officers? Typically, a captain retreats to his cabin to rest a while after takeoff. Indeed, there's corroborative evidence to suggest that the captain was not sitting in the cockpit at the time of the crash: His body was recovered from the Atlantic, whereas those of his two copilots sank to the bottom of the ocean still attached to their seats. This would suggest that Dubois was not wearing a seatbelt.
In contrast to many other airlines, it is standard practice at Air France for the less experienced of the two copilots to take the captain's seat when the latter is not there. The experienced copilot remains in his seat on the right-hand side of the cockpit. Under normal circumstances, that is not a problem, but in emergencies it can increase the likelihood of a crash.
suggesting that there was a question as to "who was controlling the plane", and that "not wearing a seatbelt" somehow "contributed". Again, ignorance and sensationalism at its worst. Stating that "in emergencies it [
placing 'inexperienced First Officers in the left seat - as if there was some 'magic' associated with that position!] can increase the likelihood of a crash." is just plain stupidity and irresponsible writing.
My earlier response to
bearfoil deals with this point and also deals with how crew breaks are usually decided. But it is worth repeating, that because the accident occurred just over 3hrs into the flight which is very close to when crew change would be occuring, we do not know whether the captain was just leaving the flight deck or returning. Arguments can be made for both scenarios. Though I think we can be certain that the captain was not in his seat, we can draw absolutely no conclusions or posit any speculations from this; there are just too many if's.
PJ2