The investigation of the accident of a Macao registered helicopter which occurred in the Hong Kong harbour in 2010 has eventually been concluded. The final investigation report was published today by the Civil Aviation Department of Hong Kong SAR (HKCAD), who was in charge of the investigation. The report indicated that the accident was due to the failure of one of the tail rotor blades which then forced the pilot to make an emergency ditching in the sea. The investigation report also pointed out that in view of the two safety recommendations made in the interim report, a series of safety measures have already been implemented during the course of the investigation.
Operated by East Asia Airlines Limited (EAA), the helicopter was put in service for running air services between Hong Kong and Macao. The aircraft, Italian made Agusta Westland AW139, is under Macao’s registration number B-MHJ. The accident occurred on 3 July 2010 at 12:00noon. A short while after taking off from the Sky Shuttle Heliport at Sheung Wan, Hong Kong, the helicopter lost its directional control. The pilot immediately put the helicopter into autorotation and performed a controlled ditching in the sea. The flight was carrying 2 pilots and 11 passengers, who were all saved while some suffered minor injuries.
The factual information of the investigation report indicated that the two pilots were properly licensed by the Civil Aviation Authority of Macao SAR (AACM) and the helicopter held a valid Certificate of Airworthiness. The cause of the accident, according to the report, was due to the failure of one of the tail rotor blades, which led to tail rotor imbalance and then caused the vertical fin structure to part off the section connecting the tail rotor assembly. With the loss of the tail rotor assembly, the helicopter eventually lost its directional control. The failure of the tail rotor blade was most probably due to manufacturing quality lapses. In addition, the report gave compliments to the pilot for being able to act promptly to perform a controlled ditching in the sea in this accident.
The HKCAD was in charge of the investigation. As it involved a Macao registered aircraft, AACM has also appointed investigators to take part in the investigation work. The investigation team also comprised of representatives from the aviation investigation bureau of Italy and the helicopter manufacturer as well as experts from a British agency who was employed by HKCAD to assist in the forensic analysis.
After the accident, EAA has immediately increased the number of inspections on the tail rotor blades of all their helicopters. During the course of the investigation, the European Aviation Safety Authority and the Civil Aviation Authority of Italy have taken into consideration the safety recommendations made by the investigation team and issued notices to the helicopter manufacturer requesting them to devise appropriate procedures to test the tail rotor blades in use and to review the manufacturing process. The helicopter manufacturer has complied with these requests and having reviewed the manufacturing process, they have introduced new production specifications including the revision of the design of the tail rotor blade, in order to increase safety and improve the effectiveness of the inspections performed on the manufacturing process.
Safety actions were also taken by AACM after the accident. The Authority has reviewed the requirement of the helicopter life saving equipment. Two measures have been implemented as a result, namely revising the Air Navigation Regulation of Macau to mandate the equipage of life jackets and floatation system for helicopters taking off or landing at a heliport where the take-off or approach path is disposed over water, and reviewing the stowage method of the life jackets and then requesting the operator to improve the method.
AACM said, “The pilot was prompt in taking the appropriate action in the shortest possible time to perform a controlled ditching in the sea. This has allowed enough time for all passengers to be evacuated and saved, which has reduced injuries to the minimum. AACM also emphasized, “The purpose of accident investigation is to find out the causal factors and any other factors that affect safety in order that similar occurrences can be prevented. In this helicopter accident, AACM has actively participated in the investigation and provided all necessary information as requested. Although the cause was mostly probably due to manufacturing quality lapses in this accident, we have nevertheless reviewed our aviation regulations and requirements to check any incompetence and hence make necessary improvement. We aim to further enhance the safety of flight operations and increase the protection of passengers’ life and properties.
