Attached is video of an RR engine on a test stand undergoing a ‘Bird Ingestion’ test.

This test is accomplished by firing a bird, [generally a dead chicken complete with feathers and internal organs at the engine]. The bird’s weight is a function of the inlet and fan diameter. This test is considered a success if the failure was completely contained, [i.e. No engine parts penetrated the engine cases or the aircraft cowling and there is no sustained external fire]. It does not take long for the engine to digest the bird as well as a significant number of its own blades & vanes. The video lasts 33 seconds and the bird is fired into the engine at the 17 second mark.

Shake, Rattle, and Roll …

Now you have some idea what the pilot of that US Air flight faced when he ingested birds into both engines simultaneously!! It also gives you a fair idea why the one engine’s mounts failed after the water landing and dropped off the wing!!