Bristow Group has taken delivery of the first two Sikorsky S-76Ds, configured for offshore oil support, initially for services in the Gulf of Mexico.

Delivery of the first VIP-configured helicopter is imminent, with emergency medical service (EMS) and search-and-rescue (SAR) variants to follow.

The deliveries come nearly four years after the first flight and more than a year since the type was awarded its baseline FAA certification. The first two aircraft are part of an order for 26 S-76Ds announced by Bristow at the 2013 Heli-Expo show in Las Vegas, Nev., in March.

The improved S-76D is powered by two Pratt & Whitney Canada PW210S turboshafts and has a Thales integrated flight-deck, four-axis autopilot, active vibration control, composite main rotor blades and an optional rotor ice protection system.

Since receiving delayed FAA certification of the baseline S-76D in October 2012, Sikorsky has been working to certify mission kits for the latest version of its popular intermediate twin helicopter. The 12-passenger offshore configuration is the first to be approved and delivered.

“There is almost as much work in certifying the kits and options and in the base aircraft,” says Carey Bond, president of commercial arm Sikorsky Global Helicopters. “We were successful out of the gate in selling into all four market segments — offshore, VIP, heavy SAR and EMS — which has meant a huge amount of certification work.”

In addition, Sikorsky has grown the capability of the S-76D beyond the baseline certification, increasing the gross weight to 11,875 lb., and expanding the hot and cold operating temperature range. “The original S-76 was not a strong performer in the Middle East because of its installed power. Now we have that in spades,” Bond says.

Early demand from multiple markets resulted in mission-kit certification tasks becoming intermixed, Bond says. “We had not anticipated EMS sales, and we thought the market would be for light SAR, not heavy.”

Certification flight-tests on the VIP configuration were completed late in 2013, the SAR variant is in flight test for delivery to Japan by mid second-quarter, and approval and delivery of the EMS configuration is planned for August 2014.

Sikorsky is continuing to grow the helicopter, expecting the cold-weather operating temperature to get down to -20F, with a goal of -40F, and increasing hot-day density altitude to 10,000 ft., with an ultimate goal of 15,000 ft. Software updates for the Thales cockpit are next, he says.

Work to certify the rotor ice protection system, which comprises electrically heated mats on the main and tail rotor blades, began in December and will continue next winter. “Certification is a matter of finding the right ice,” Bond says. “The heater blankets and wiring are in the basic aircraft.”

Compared with the previous S-76C++ model, the S-76D is 15 kt. faster, at 171 kt. in straight and level flight, he says. The D is 5% more fuel efficient than the C++ and the gross-weight increase helps offset increased weight from new equipment such as crash-attenuating stroking seats.

With a backlog exceeding $700 million, Sikorsky had delivered almost 30 green aircraft into completion by the end of 2013 and inducted the 51st cabin — manufactured by Aero Vodochody in the Czech Republic — on to the final-assembly line at Coatesville, Pa. “We are in full-rate production,” Bond says.