Luis Pedro Costa is to stand trial for allegedly breaching security and locking himself inside the cockpit of a British Airways plane.
He was due to return to his home in Chiswick but has not been seen since.
Costa is a Portuguese man, described by police as approximately 5ft 8inches tall of medium build with brown eyes, balding with brown hair and currently has a beard.
Costa also has a tattoo of a Chinese symbol on his upper left arm.
Officers are extremely concerned for Costa's well-being and mental welfare. He is not considered a risk to the public but police need to trace him urgently.
Anyone who has seen Luis Pedro Costa or knows of his whereabouts is asked to contact Hounslow Police via 101.