What happened
On 9 June 2017, an Agusta AW139, registration G-CIPW, was conducting a commercial passenger charter flight in the North Sea. The flight was scheduled to depart Norwich Airport, visiting several platforms including the Kelvin and Viscount installations, before returning to base.
During the flight preparation, a discrepancy existed between the paper route strip provided to the crew and the digital Flight Planning Software (FPS). While the paper strip used the identifier 'OD' for the intended destination, the FPS still listed the destination as 'VISCOUNT'. The co-pilot, who was relatively new to the base, mistakenly assumed 'OD' was simply an alternative name for the Viscount platform.
As the crew approached the destination, the pilot monitoring attempted to contact the Helicopter Landing Operator (HLO) via radio. Due to weak signal strength, the crew could only hear a partial message stating that the deck was available, but they could not confirm the platform name. Upon landing, the crew discovered the platform was indeed the Viscount, but they were actually intended to land at the Vampire platform. After realizing the error, the crew departed the unmanned installation and proceeded to the correct location without further incident.
The investigation
The AAIB investigation focused on the conflicting identifiers used by the helicopter operator and the chartering company. It was established that the charterer had requested a change in destination from the Viscount to the Vampire platform, but this change was not reflected in the operator's FPS.
Investigators found that the co-pilot had relied on the FPS data, which matched the commander's expectations, and therefore did not identify the error. The commander noted that while he was familiar with the varying naming conventions, he had been distracted by forecasted thunderstorms and had not cross-checked the paper route strip against the digital flight plan. Additionally, the investigation examined the communication difficulties experienced during the final approach due to the use of portable radios by the HLO.
Findings
- The crew landed on the incorrect platform because the operator's flight planning software had not been updated to reflect a change in the flight schedule.
- Conflicting naming conventions between the charterer's identifiers and the operator's software contributed to the confusion.
- The co-pilot's lack of familiarity with the specific platform codes led to the incorrect assumption that 'OD' and 'VISCOUNT' were the same location.
- The commander's attention was diverted by weather-related concerns regarding potential thunderstorms.
- Poor radio signal strength prevented the crew from clearly hearing the platform name during the final approach.