What happened
On 12 July 2022, a Bell 505 helicopter, registration PK-WSU, completed a sightseeing flight at the Flybali Heliport in Ungasan, Bali. The flight, operated by Urban Air under the PT Whitesky Aviation certificate, had been touring local landmarks including the Garuda Wisnu Kencana Statue and Uluwatu Temple.
As the pilot began the engine shutdown procedure, the main rotor speed had decreased to approximately 60% RPM. During this phase, a loud noise occurred accompanied by vibrations in the flight controls. An engineer on the ground, positioned near the tail boom between the horizontal stabilizer and the tail rotor, was struck by the rotating blades. The impact caused substantial damage to the aircraft, including broken tail rotor blades and a cracked gearbox. The engineer sustained injuries to his back and right hand and passed away 11 days later due to complications from septic shock and acute respiratory distress syndrome.
The investigation
The KNKT investigation focused on the medical status of the maintenance personnel and the regulatory framework for license renewals. It was established that the engineer had been treated for bipolar disorder since 2014. Recently, following a self-harm incident in June 2022, his medication dosage—which included atypical antipsychotics, antidepressants, and psychoactive agents—had been increased.
The investigation found that while Indonesian regulations prohibit performing duties under the influence of psychoactive substances, the specific process for renewing an Aircraft Maintenance Engineer License (AMEL) lacked detailed requirements regarding the use of prescribed psychoactive medications. Furthermore, the company's medical check-up procedures for employees focused on physical health but did not include mental health assessments.
Findings
- The engineer was performing duties while using an increased dose of medication containing psychoactive substances.
- The sedative side effects of the medication likely caused a decrease in situational awareness, leading the engineer to enter the tail rotor path.
- There was no regulatory requirement for maintenance engineers to undergo medical assessments for license renewal.
- The operator lacked a system to monitor the mental health or medication usage of its technical staff.
Safety action
Following the accident, PT Whitesky Aviation implemented several safety measures, including recurrent training on human factors and the Safety Management System, enhanced supervision of personnel movement during helicopter landings, and improved hazard identification protocols at the heliport.