Sikorsky has received US regulatory approval for a life-extension to a critical gearbox component on its S-92 helicopter that it believes will contribute to alleviating the availability challenges currently afflicting the heavy-twin.
Through the life-extension plan, certain main gearbox (MGB) housings can now be run to a maximum of 5,500h – a significant increase over the current 4,300h limit.
S-92 operators, particularly those in the oil and gas sector, have for at least the past year been faced parts shortages, notably of MGBs, that have left significant numbers of the global fleet idled.
Sikorsky has been working on several initiatives to improve the situation, including investment in its supply chain, but the airframer has also now gained clearance from the US Federal Aviation Administration (FAA) to offer a one-time life extension for certain MGB housings.
This, it says, will contribute to “mitigating downtime, and increasing operational readiness and availability for the fleet”.
Using health and usage monitoring systems (HUMS) data from across the S-92 fleet, Sikorsky says it has been able to develop a “methodology to more accurately determine the life-limit for parts”, an approach it calls “LifePlus”.
Using the LifePlus methodology and HUMS data for each housing, Sikorsky says it can build an accurate figure for the remaining component life based on actual aircraft usage.
Depending on that data, this should enable operation of a housing “beyond the current 4,300-hour limit”, it says, up to a 5,500h maximum.
This, says Leon Silva, vice-president of Sikorsky’s Global Commercial and Military Systems business, represents “an additional 12-18 months for an average S-92 offshore oil operator, and more than 24 months for others.”
But he stresses that as the figure is “based upon individual usage” the additional hours applicable to each housing will vary.
Sikorsky says it is now working with the European Union Aviation Safety Agency (EASA) to expand the life-extension initiative to operators outside of the USA.
“Sikorsky has begun the validation process with EASA through communication with the FAA. A timeline for completion is still being determined in coordination with the FAA,” it says.
“The FAA certification of the main gear box housing earned life credit is just one of the many examples of Sikorsky’s continued investment in the S-92 platform,” adds Silva.
“For over a decade, we have been investing in LifePlus, and we are thrilled to see it becoming a game changer for the industry.”
LifePlus has previously been used to gain approval for a life extension on the S-92’s main rotor hub, raising the retirement time from 9,000h to 15,000h.
