Pilots’ actions after the bird strike are an early focus of the investigation, according to people familiar with the probe.

Authorities have suggested that migratory bird strikes were the cause of last month's deadly plane crash in South Korea, according to multiple reports.

Jet engines are incredibly powerful, complex pieces of precision engineering, running at the finest of tolerances; bird strikes can push these tolerances to the limits. When a bird is ingested into an engine, the first thing the unfortunate creature will meet is the fan blades, typically rotating between 2200 rpm and 4500 rpm.