Vertical velocity at impact
As there were a lot of ACARS messages within the 2h 10 'window', could the aircraft already have been in trouble (and starting to drop) sometime before, say between 2h 08 and 2h 09? Also if ACARS stopped because both engines had been lost (physical or flame-out)the impact could be sometime after 2h 14, say between 2h 15 and 2h 16. This would give a descent time of 6 to 8 minutes. If terminal velocity was reached quite quickly, this would give an impact velocity of about 5000 ft/min