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Mar 11, 2025

Sikorsky highlights S-92 Phase IV main gearbox in Verticon preview - Vertical Mag

Shortly before Vertical Aviation International (VAI) kicked off its annual Verticon gathering in Dallas, Texas, Sikorsky invited members of the media to its Stratford, Connecticut, headquarters and

Shortly before Vertical Aviation International (VAI) kicked off its annual Verticon gathering in Dallas, Texas, Sikorsky invited members of the media to its Stratford, Connecticut, headquarters and manufacturing facility for a preview of upcoming products and future concepts.

“We pioneer flight solutions that bring people home everywhere, every time,” said VP of global commercial and military systems, Leon Silva, reciting the expression that defines the goals of the Sikorsky company.

“This rings true with our teams and it brings us back to the reasons why Igor Sikorsky originally invented the helicopter.”

One of the key products in achieving that lofty aspiration is the S-92.

The twin-engine medium-lift helicopter has been a mainstay in the passenger transport realm for over 20 years.

With the ability to seat up to 19 occupants, the vast cabin with its six-foot ceilings and 700 ft3 volume has been utilized by operators for SAR, offshore oil-and-gas, VIP, and head of state, most recently as the basis of the U.S. Presidential transport fleet, the VH-92A.

Over its two decades of service, the S-92 has accumulated over 2.4 million flight hours on the 276 aircraft being operated in 28 countries worldwide, averaging more than 13,000 hours in the air each month.

While already known for its robust build quality and excellent safety record, following an inflight issue in 2012, Sikorsky set about to improve and strengthen the main rotor gearbox in the S-92.

“It’s been about a 10-year effort, and we’ve spent well over $100 million,” Silva explained. “However, this is not an economic decision, this is an investment that we will never get back. But it is an investment in our customers and their safety. We saw an opportunity to make it better and that is what we are doing.”

The S-92 Phase IV main gearbox features an auxiliary lubrication system, with an additional three gallons of oil and other upgrades, that automatically engages in the event of primary oil pressure loss, eliminating the need for immediate landing and allowing operators to safely reach their destination.

This revolutionary solution has been validated through more than 800 hours of rigorous testing, Four gearboxes have been completed at the company’s Stratford headquarters, and customers are already vying to become first adopters.

During the ongoing testing process, engineers completely cut off the primary lubrication system and allowed the auxiliary system to take over.

“Once they reached seven and half hours with no failures, they realized they were well beyond the fuel capacity of the S-92 and there was no reason to continue the test. It is that robust and that reliable,” Silva proclaimed while showing one of the gearboxes on its test stand.

This validates Sikorsky’s Fly Home initiative, eliminating the need to land immediately.

“The Phase IV main gearbox builds upon its predecessor’s reputation as one of the best and most reliable gearboxes in the industry, and is yet another example of Sikorsky’s continued investment in the S-92 platform,” said Silva.

“We have spent more than a decade designing, testing, and optimizing the Phase IV main gearbox for exceptional performance, and we are thrilled to see it become a new industry standard.”

With plans for an S-92B model being shelved, the Phase IV main gearbox will be part of the S-92A+ program that will include an additional 1,200 pounds (544 kilograms) of useful load, LifePlus enhanced component lives, and enhanced range.

Silva also clarified that the Phase IV gearbox will be assembled concurrently with the Phase 3 and can be “dropped in,” essentially as a plug-and-play swap, and both gearboxes will be offered to customers at the time of purchase.

These upgrade announcements follow several additional enhancements to the S-92 helicopter in recent months, including increased scheduled inspection intervals and a one-time life extension for specific main gearbox housings.

These enhancements will eliminate more than a full year of downtime caused by inspections and allow operators to safely keep their aircraft in service and generating revenues longer. The earned life credit is up to 1,200 hours / 3,600 ground-air-ground cycles, representing an additional 12 to 18 months for an average S-92 offshore oil operator and more than 24 months for others.

The S-92A Phase IV main gearbox is completing final testing with Federal Aviation Administration (FAA) certification anticipated in 2025.