Originally Posted by
awblain
eye . . . optical performance. The detectors are a bit flakey, but the processor is very fast and well tuned.
There are at least three other factors on sighting the birds.
The first is the tendency for the eye to focus at infinity. This was probably not a factor here at low altitude.
Next is the processor time. From an object becoming detectable by the eye to the brain recognising that there is an object there is a finite time - we are not talking reaction here, just the time before the brain has acknowledged the object's presence. In a military study of aircraft closing at I believe over 1000 kts (may be a bit less) it was determined that the observed aircraft would actually be behind the observer by the time the brain acknowledged its presence. Again that is unlikely to be the case in a 'low speed' bird strike.
The last factor is human. Was there a sufficiently large structure in the forward area to cause a blind spot? An object in the blind spot will remain hidden if it is on a collision course. To avoid this it is necessary for an active external scan and moving the head to look around a blind spot. If the PF was head down then the PNF would be looking out - this would also reduce the time available for reaction and avoidance. I am sure that this will be considered here.