Originally Posted by
lomapaseo
I seriously doubt you could count birds ingested. Maybe a count of those that missed. However the experts could estimate birds that were ingested through a variety of means, including groups of dented fan blades and dents across the leading edge plane surfaces. Even with a hundred or so gulls in front of the engine you probably would get no more than 2 in a CFM56. And like I said before why would that many gulls be allowed on an active runway.
The cert basis is based on historical probabilities and not on lets imagine how many can fit
I honestly have no idea how they count the number of injested birds. I suspect birds' DNA is as unique as human, but I have very little knowledge of that area. In the case of UA178 I simply counted the number of injested birds from a video I saw online which shows both the image and the distinctive sound of each strike.