Introduction
On the morning of 31 March 2022, two Airbus Helicopters EC130 helicopters, operated by Microflite, commenced a passenger transport flight from the Batman Park helicopter landing site in Melbourne to Ulupna on the northern border of Victoria. The first helicopter, registered VH-WVV, performed a U-turn overhead Mount Disappointment to avoid entering cloud. The second helicopter, registered VH-XWD, entered a high rate of descent and collided with terrain while attempting to follow with the U-turn. The helicopter was destroyed and the five occupants were fatally injured.
Route Planning
The weather forecast for the Mount Disappointment area indicated broken stratus cloud at 2,000‑3,000 ft above mean sea level (AMSL) and a mixture of broken cumulus/stratocumulus cloud at 3,000-8,000 ft. The peak of Mount Disappointment is 2,605 ft and the upper limit of uncontrolled airspace was 3,500-4,500 ft. This indicated that cloud was forecast to develop below visual meteorological conditions (VMC) from ground level up into controlled airspace, making the route over Mount Disappointment unsuitable for visual flight rules (VFR) planning. The forecast for Kilmore Gap, a recommended VFR route, included broken cloud at 3,000 ft with temporary periods of cloud on the ground.
What the ATSB Found
The ATSB found that, while VMC prevailed at the departure point, the pilots planned and commenced a route for which instrument meteorological conditions (IMC) were forecast. The pilots continued as conditions deteriorated below VMC until a rapid course change was required to avoid entering cloud. The accident pilot did not maintain adequate control of the pitch attitude during the attempted U-turn, leading to a high rate of descent and collision with terrain. This pilot had no instrument flying experience, and the helicopter was not equipped with artificial stabilisation. The operator had not mandated IIMC recovery training or basic instrument flying competency checks, nor introduced an IIMC recovery procedure or a pre-flight risk assessment for marginal weather. The standby artificial horizon in VH-XWD was not powered on and erroneously indicated an unusual attitude as the helicopter approached cloud, momentarily distracting the pilot. Additionally, the helicopter had not been modified with service bulletins to prevent turbine blade shedding. These two factors were not considered contributory but increased risks of spatial disorientation and post-impact fire.
Safety Actions Taken
As a result of this accident, the operator drafted a dedicated risk assessment for VFR into IMC, upgraded fleet EC130 and AS350 helicopters with Garmin G500H displays and terrain alerting, modified AS350s with Garmin GFC 600H flight control system, acquired ICARUS training hoods, introduced basic instrument and IIMC recovery training, updated proficiency checks to include IIMC avoidance and recovery, added the Helicopter Association International '56 Seconds to Live' course, introduced a pre-flight risk assessment tool and a company 'Task rejection' policy, and obtained an Airbus Helicopter Training Centre approval. The ATSB issued a safety recommendation to the Civil Aviation Safety Authority to address the risk of VFR IIMC events in rotorcraft air transport.
Safety Message
The ATSB encourages all pilots to develop knowledge and skills to manage IIMC risk, supported by educational material on flight planning and weather assessments. Decision-making in marginal weather can be aided by pre-flight risk assessment tools. At an organisational level, the risk of helicopter IIMC should be managed with multiple layers of controls, including training, procedures, and equipment such as autopilots and terrain awareness systems.