What happened
On 22 November 2017, a Garuda Indonesia Airbus A3/330-200, registration PK-GPM, was operating a scheduled passenger service from Hong Kong International Airport to Soekarno Hatta International Airport. The flight carried 167 people, including 155 passengers and 12 crew members.
Shortly after climbing through Flight Level 200, the pilot in command (PIC) attempted to stand up from his seat to hang up his coat. Upon standing, the pilot became dizzy and lost consciousness. The second in command (SIC) immediately took control of the aircraft and declared an emergency, requesting an immediate return to Hong Kong. During the descent, a flight attendant and a company pilot traveling as a passenger assisted the crew, providing portable oxygen to the unconscious pilot. The aircraft landed safely in Hong Kong without any injuries or damage to the airframe.
The investigation
The KNKT investigation focused on the medical state of the pilot prior to the flight. It was established that the pilot had been suffering from significant gastrointestinal distress, having experienced multiple episodes of bowel movements since arriving in Hong Kong. Medical examinations performed at hospitals following the incident revealed that the pilot was suffering from gastroenteritis caused by an infection of E. coli and P. shigelloides.
Investigators noted that the pilot had consumed various local foods and beverages in the days leading up to the flight, which likely contributed to the infection. While the pilot had informed the second in command of his symptoms and was offered antidiarrhea medication, he chose not to take it, believing his condition had stabilized because he had not had a bowel movement immediately prior to departure.