Sikorsky is launching two new variants of its heavy twin – an S-92A+ upgrade package for in-service helicopters, and the new-production S-92B. Both new models include new flight computing technology and main gearbox, as well as an interior common to search and rescue and offshore operations. The new Phase IV gearbox is constructed of aluminum, replacing the original magnesium, and has a new lubrication system, improving reliability. A GE Aviation CT7-8A6 engine, which improves hot-and-high performance, is also available as an option. New production S-92B variants will offer a few differences from the A+ with larger cabin windows, updated cabin entry door, and titanium side frames to strengthen the airframe.