En ligne de vol
This argument is getting boring.
As you don't agree on vocabulary / semantics, take this example ( I am French, a pilot and teach flying,. that should do to my credentials, right ?)
Take a tail dragger just before it starts its takeoff roll ; it sits on its tailwheel.
Now, accelerate, the pilot will give a forward control column movement ; the tailwheel raises and the pilot stops the movement there : He's now accelerating and he has put his aircraft "en ligne de vol".
That, and only that aspect is "en ligne de vol".
Another aspect of this discussion that's getting silly is people beating to death the different and seemingly contradictory aspects of the debris to promote their own ideas (and bashing the BEA at the same time).
Considering that the airplane is some 60 meters long - or 200 feet -, is it really difficult to understand that the same forces were not seen throughout the whole structure : some parts hit first (whether the airplane was en ligne de vol or not), that initial impact forces might have been seriously diminished through the energy absorption of the first "hits", including the dissipated energy through structural failures or breakages and finally that it would be surprising that we won't see some whiplash effects.
To think that the aircraft hit the water verically in a flat attitude, meaning that the impact was a single one and concerned the whole structure at the same 1,000,000 th of a second is silly and denotes an astonishing misunderstanding of dynamics.