A helicopter grounded at the offshore oil production vessel Terra Nova earlier this week is back in full service today, according to Cougar Helicopters.
The aircraft was grounded aboard the vessel 5 p.m. Tuesday.
Instrumentation aboard the helicopter indicated a hydraulic system pump was remaining in “high mode,” according to the operator, leading to a decision to hold the aircraft offshore for inspection.
On Wednesday morning, at 7:30 a.m., Cougar sent a second flight to the FPSO, carrying company technicians, to inspect and clear the grounded aircraft for return to St. John’s.
“The No. 3 hydraulic system is a redundant system that provides powered capability to the landing gear and ramp door (both of which can be manually activated). It has two modes, high and low. There was no caution or warning indication presented, the shutdown was a proactive measure,” Candace Moakler, a representative for Cougar, stated in an email to The Telegram.
The technicians completed the shutdown and checks, but could not immediately return to St. John’s due to weather.
Both Cougar helicopters at the FPSO returned to St. John’s Wednesday, with the inspected helicopter returning at 3:30 p.m.
The FPSO is being operated by Suncor, about 350 kilometres southeast of St. John’s.
It has one helideck. However, there is space onboard where a helicopter “can be safely parked and secured,” allowing for a second helicopter to land on the helideck, Cougar has previously explained for The Telegram.
That explanation came during a similar event, also aboard the Terra Nova, earlier this year. In that case, a Cougar flight was grounded as a result of an indicator light. A second flight was sent out, carrying Cougar technicians, in order to check the aircraft and, ultimately, bring it back to St. John’s.
In that case, following a safe return, Cougar Helicopters decided to "proactively replace the gearbox" on the Sikorsky S-92 model aircraft.
The replacement was deemed necessary after communication with the helicopter's manufacturer. It was to "fully ensure the fidelity of the gearbox," according to statements made by both companies.
Other turn-arounds and machinery checks, due to indicator lights, have been reported by the company. An incident in April 2011 involved the restart of a helicopter at the Terra Nova FPSO.
Read also these previous stories: