Flocks of Geese v Airliners - including looking at probabilities of Geese into both engines of Twin Airliners:
http://www.aaib.gov.uk/cms_resources...pdf_500040.pdf
So:
I would still like to know what "large brown birds" bought down the aircraft. About the only large brown birds as described are geese, and geese don't flock like starlings, they fly in a 'V' (as noted by pattern_is_full). Ingesting one, fine, but two? You would have to exactly fly to intersect with the V-pair which were the same distance apart as the donks. The odds must be vanishingly small.
it would seem the answer is in fact significantly large
A rather prophetic report
NoD