An American man who caused a bomb threat onboard a Singapore Airlines flight from San Francisco in September resulting in fighter jets scrambling to intercept the Airbus A350-900 has been sentenced to three weeks in jail on a separate charge of assaulting a member of the cabin crew.

La Andy Hien Duc, 37, has been deemed a danger to the public following the incident onboard Singapore Airlines flight SQ33 on September 28 and he is expected to be deported on Sunday after already spending four weeks in jail on remand.

During a court hearing, prosecutors described how around six hours into the 16-hour flight, Hien Duc claimed there was a bomb hidden in a bag onboard the aircraft. Hien Duc grabbed someone else’s bag from the overhead locker and then assaulted a male flight attendant as the crew later rushed to restrain him.

Singapore’s Ministry of Defence scrambled several F-16 fighter jets to intercept and escort the aircraft into Singapore Changi Airport while flight attendants searched the cabin for anything suspicious.

On arrival in Singapore, the aircraft was sent to a remote location on the airfield where teams from the army’s Chemical, Biological, Radiological and Explosives Defence Group boarded the plane.

Hien Duc was taken into custody and later diagnosed with schizophrenia. A psychiatrist from Singapore’s Institute of Mental Health concluded that Hien Duc’s mental health issues meant he posed a danger to the public.

“The stressors of being in a foreign country, including the fact that he has no fixed place to stay and no one to monitor his compliance with his medications, are risk factors for relapse,” the prosecutor told the court, as reported by the Straits Times.

The court gave Hien Duc a “stern warning” over the bomb threat element of the incident, and he cannot be charged with the same offence again in the future.