What happened
On 18 November 2009, an Israel Aircraft Industries Westwind 1124A aircraft, registered VH-NGA, was operated on an air ambulance flight from Apia, Samoa to Norfolk Island, Australia. Two flight crew, a doctor, a flight nurse, a patient and a passenger (the patient’s husband) were on board.
On arrival at Norfolk Island at night, there was low cloud and the aircraft had insufficient fuel to divert to another airport. After four unsuccessful approaches, the flight crew ditched the aircraft 6.4 km west-south-west of the airport.
During the ditching, the aircraft encountered significant impact forces, and the flight nurse and first officer were seriously injured. The aircraft cabin rapidly flooded, and all six occupants evacuated from the aircraft, but with only three of the six life jackets on board and neither of the aircraft’s life rafts. The evacuees were rescued 85 minutes later by personnel on a search vessel launched from Norfolk Island.
What the ATSB found
The flight crew were conducting a long-distance flight to a remote island at night. At the time the flight was planned, the aerodrome forecast for Norfolk Island indicated the weather conditions at the time of arrival would be above the alternate minima.
Contrary to the consistent practice of the operator’s Westwind fleet for such flights, the flight departed with full main tanks (or about 7,200 lb of fuel) rather than full main tanks and tip tanks (about 8,700 lb). The reasons why the captain elected to depart without the maximum fuel load on this occasion were not fully determined. However, the ATSB found the captain’s pre-flight planning did not include many of the elements needed to reduce the risk of a long-distance flight to a remote island. These included miscalculating the total fuel required for normal operations, not calculating the additional fuel required for aircraft system failures, not obtaining relevant forecasts for upper-level winds, and not obtaining current information about potential alternate aerodromes. Although there was no requirement for the flight to depart with alternate or holding fuel, the fuel on board was insufficient to meet operator and regulatory requirements for the flight to allow for aircraft system failures.
Although the operator’s Westwind pilots generally used a conservative approach to fuel planning, the operator’s risk controls did not provide assurance there would be sufficient fuel on board flights to remote islands or isolated aerodromes. Limitations included no explicit fuel planning requirements for such flights, no formal training for planning such flights, no formal guidance information about hazards at commonly-used aerodromes, no procedure for a captain’s calculation of the total fuel required to be checked by another pilot, and little if any assessment during proficiency checks of a pilot’s ability to conduct fuel planning.
There were also limitations with Australian regulatory requirements. Other than requirements for fuel planning of passenger-carrying charter flights to remote islands, there were no explicit fuel planning requirements for other passenger-carrying flights to remote islands, and no explicit requirements for planning flights to isolated aerodromes. In addition, air ambulance flights were classified as ‘aerial work’ rather than ‘charter’. Consequently, they were subject to a lower level of requirements than other passenger-transport operations (including requirements for fuel planning).
During the flight, the weather conditions at Norfolk Island deteriorated below the landing minima. Air traffic services in Nadi and Auckland did not provide the flight crew with all the information that should have been provided. In addition, the flight crew did not request sufficient information prior to passing the point of no return (PNR), and the captain did not use an appropriate method for calculating the PNR. Related to these actions, the operator’s risk controls did not provide assurance that its pilots would conduct adequate in-flight fuel management activities during flights to remote islands or isolated aerodromes. The Civil Aviation Safety Authority (CASA) had also published limited guidance material regarding in-flight fuel management.
After the aircraft passed the PNR, there were opportunities to minimise the risk associated with the developing situation. However, the flight crew did not effectively discuss approach options, and they did not effectively review their fuel situation and consider alternate emergency options prior to ditching the aircraft. The flight crew did not refer to the ditching checklist and the final approach was conducted at an airspeed significantly below the reference landing speed (VREF), which increased the descent rate just prior to impact. A range of local conditions influenced the performance of the crew during the latter stages of the flight, including workload, stress, time pressure and dark night conditions.
In addition to the rapid flooding of the aircraft cabin, the occupants’ evacuation was hampered by there being no formal, specific procedures and limited training regarding on how to secure life rafts in an appropriate, readily accessible location prior to a ditching, and a designated storage location for the stretchered patient’s life jacket. In very difficult circumstances, the nurse and doctor did an excellent job evacuating the patient, and then assisting the injured first officer and the patient in the water, both of whom did not have life jackets.
Due to the inherent limitations of most emergency locator transmitters (ELTs) for a submerged aircraft, and the limited information provided by the flight crew regarding the location of the ditching, search and rescue personnel initially had no reliable information about where to search for the aircraft. It was fortunate that a firefighter made a chance sighting of the captain’s torch, resulting in the search effort being redirected to the appropriate area and the successful rescue of the evacuees.
In addition to issues associated with fuel planning and in-flight fuel management, the ATSB identified safety issues with the operator’s risk controls for emergency procedures and training, fatigue management, crew resource management training and flight crew training for newly-installed systems on the accident aircraft. The ATSB also identified limitations with the operator’s hazard identification processes and the definition of roles and responsibilities of key management personnel, and the processes used for the operator and air ambulance provider for conducting pre-flight risk assessments. Limitations were also identified with the processes used by CASA for planning surveillance, scoping audits and conducting audits.
What's been done as a result
Following the accident, CASA conducted a special audit of the operator, and this audit involved an extensive assessment of the operator’s air ambulance operations. The operator voluntarily ceased its Westwind operations and collaborated with CASA during the audit. During this process, the operator reviewed and substantially enhanced its risk controls and management oversight of flight/fuel planning and in-flight fuel management. It also enhanced its risk controls and management oversight of many other areas of its air ambulance operations.
In 2014, CASA modified the requirements for operations to Australian remote islands, so that all passenger-carrying transport flights, including air ambulance flights, were required to depart with alternate fuel. In addition, in 2012 CASA initiated action to change the regulatory classification of air ambulance (or medical transport) flights from aerial work to air transport. However, although CASA released a Notice of Proposed Rule Making about this issue in 2013, no changes have yet occurred. Accordingly, the ATSB issued a safety recommendation to CASA to continue reviewing the requirements for air ambulance operations and address the limitations associated with the current classification of these flights. The ATSB also issued two other recommendations to CASA for it to continue its activities to address the limitations with the requirements and guidance for fuel planning of flights to isolated aerodromes and the requirements and guidance of in-flight fuel planning.
In addition to these actions, since 2009 there have been improvements in a range of other areas. These include improvements to CASA’s surveillance processes, weather forecasting processes at Norfolk Island, and the publishing of advisory information about the hazards at remote island aerodromes. In addition, there now exists an enhanced capability for satellites to detect the location of ELT signals from aircraft involved in ditchings and similar impacts where the ELTs are unable to emit signals for extended periods.
Safety message
The investigation report contains 36 safety factors that provide lessons to flight crews, operators, regulators and/or other organisations. Overall, the most fundamental lesson for all flight crew, operators and regulators is to recognise that unforecast weather can occur at any aerodrome. Consequently, there is a need for robust and conservative fuel planning and in-flight fuel management procedures for passenger-transport flights to remote islands and isolated aerodromes.
Additional safety messages include:
- Flight crew should discuss and consider options to manage threats when there is time available to do so.
- Operators should ensure their flight crew proficiency checks assess the performance of all key tasks required of their flight crew.
- Operators should not rely on informal risk controls for managing the performance of safety-critical tasks, particularly when there is significant turnover of pilots in a fleet.
- Operators of air ambulance flights should ensure medical personnel have clearly defined procedures and appropriate practical training for using the emergency equipment on board to ensure they can effectively assist a patient in the event of an emergency.
- All organisations in safety-critical industries should use proactive and predictive processes to identify hazards in their operations.
- Organisations that use a bio-mathematical model of fatigue as part of their fatigue risk management system should ensure they have a detailed understanding of the assumptions and limitations associated with such models.
- Regulators should develop effective methods for obtaining, storing and integrating information about operators and the nature of their operations so that they can develop effective surveillance plans.
