.... remind me of which recovered articles allowed the 'line of flight' BEA conclusion (ie is it in any doubt with respect to the whole airframe ?
Page 32 of the English version of Interim Report No. 2 says:
From these observations it can be deduced that:
The aircraft was probably intact on impact.
The aircraft struck the surface of the water with a positive attitude, a low bank and a high rate of descent.
There was no depressurisation.
The observations referred to include:
The vertical stabiliser’s side panels did not show signs of compression damage.
The breaks seen at the level of the lateral load pick-up rods were the result of the backwards movement of the attachments and centre and aft frames. The observations made on the vertical stabiliser are not consistent with a failure due to lateral loads in flight.
The observations made on the debris (toilet doors, partitions, galleys, cabin crew rest module, spoiler, aileron, vertical stabiliser) evidenced high rates of compression resulting from a high rate of descent at the time of impact with the water.
This high rate of compression can be seen all over the aircraft and symmetrically on the right- and left-hand sides.
These observations are not compatible with a separation of the aft part of the fuselage in flight.
The damage found at the root of the vertical stabiliser was more or less symmetrical, as were the deformations due to the high rate of compression observed on the various parts of the aircraft. This left-right symmetry means that the aircraft had low bank and little sideslip on impact.