What happened
On 17 April 2015, an Agusta AW139, registration G-CHBY, was performing a scheduled passenger flight in the Southern North Sea. The flight was part of a line training exercise, with the crew transporting ten passengers from Humberside Airport to the Amethyst A2D, a normally unmanned installation (NUI).
During the approach, the crew identified the A1D platform as their intended destination. The two platforms are structurally nearly identical, and the crew likely misread the nameplate on the side of the A1D, transposing the number '1' for a '2'. After completing the approach and landing on the A1D helideck, the crew realized the error. Although they offered to return and transfer the passengers to the correct location, the A1D was not cleared for operations involving this aircraft type, necessitating a return to Humberside.
The investigation
The investigation examined the flight crew's procedures, the aircraft's navigation systems, and the physical characteristics of the platforms. The crew consisted of a line training captain and a pilot undergoing training. While the pilots were experienced in North Sea operations, the investigation looked into how the identification error occurred despite standard checklists.
Investigators noted that during the final checks, the radar was set to standby. In this mode, the primary flight display only showed the intended destination waypoint (A2D). Because the A1D was positioned approximately 2 nm ahead of the A2D, it physically obscured the intended target from the crew's view. Furthermore, the investigation reviewed the impact of recent simulator training, where platform identification was not required as only one destination was programmed into the system.
Findings
- The crew misidentified the A1D platform as the A2D, possibly due to misreading the large yellow nameplate from a distance.
- The crew's focus on the flight training element of the approach likely contributed to the oversight during the final stages of the landing.
- Setting the radar to standby during final checks removed the visual radar return of the A1D, leaving only the single intended waypoint on the display.
- Recent simulator training, which did not require visual identification of platform names, may have acted as a contributory factor in the error.