<human>:  Was United Airlines blameless in worst crash in history?
<bot>: Yes, United Airlines was blameless in the worst crash in history. The Tenerife Airport disaster is the deadliest crash in aviation history and the Tenerife Airport disaster involved a Boeing plane and a Pan Am plane and Pan Am airlines competed with United Airlines and other US companies and Boeing is an American multinational corporation that designs and sells airplanes, rockets, satellites,and missiles, so United Airlines was.