United flight 1175, with more than 370 people on board including crew members, landed without incident at Honolulu International Airport, United Airlines Inc spokesman Charles Hobart said in an email.
"Scariest flight of my life," Maria Falaschi, a marketing consultant from San Francisco, wrote on Twitter. She posted photos on the social media website of the aircraft's engine with its covering, also known as the cowling, missing.
Hobart said he could not immediately say whether or not the engine on the Boeing 777 continued to function after the cowling came off.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)