Most large commercial jet engines include design features that ensure they can shut-down after " ingesting " a bird weighing up to . The engine does not have to survive the ingestion , just be safely shut down . This is a ' stand-alone ' requirement , '' i.e. '' , the engine , not the aircraft , must pass the test . Multiple strikes ( from hitting a bird flock ) on twin-engine jet aircraft are very serious events because they can disable multiple aircraft systems , requiring emergency action to land the aircraft , as in the January 15 , 2009 forced ditching of US Airways Flight 1549
US Airways Flight 1549
US Airways Flight 1549
Bird strike