Orders are growing for Sikorsky's civil/military S-92, rewarding the company's gamble in launching it


Much is riding on the success of the privately developed S-92 multirole helicopter - not least the future of Sikorsky. The gamble finally appears to be paying off with the announcement of three prospective deals within months of the company's low-key decision to launch full-scale production of the new medium-size civil/military helicopter.

Sikorsky has letters of intent (LoI) and at least one deposit in hand for nine civil helicopters, including two options. Although relatively few, these come at a critical juncture for the S-92 programme, with three major international competitions in Scandinavia, Oman and Portugal nearing a conclusion, and orders for nearly 140 military helicopters at stake.

"We are looking at a total market over the next 10 to 15 years in the order of 1,600 aircraft for what used to be called the free world, excluding Russia and China," says Tommy Thomason, Sikorsky vice-president civil programmes. "Internally, we're estimating sales of 600 to 800 S-92s split about one-third for the civil market and two-thirds military."

Sikorsky has identified at least five markets where it is looking to build on the sales success of its S-70, S-76 and S-61 models. In the civil sector, manufacturers hope the surge in oil prices will benefit the offshore support industry. Oil companies and operators were strongly represented on the S-92 customer advisory board.

Offshore appeal

In January, Cougar Helicopters was the first to place a deposit for three helicopters and two options, starting with deliveries in 2002. The Nova Scotia and Newfoundland-based company is contracted to support offshore drilling in the Hibernia field. Sikorsky hopes the S-92's 19-seat capacity and 880km (475nm) maximum range will interest other former S-92 advisers such as North Sea operator Bristow and Gulf of Mexico-based Petroleum Helicopters.

"The offshore oil industry is where we're starting and the S-61 has been very popular there," says Thomason. "There are two or three companies we're working with on specific proposals." Sikorsky is also looking to the airline industry, where the 14-seat S-76 has proved successful and is in service with five carriers.

Two such operators, Vancouver-based Helijet Airways and, more recently, Copterline of Helsinki, have each signed LoIs for two S-92s. Commercial sales efforts are also being targeted at fixed-wing operators of smaller 19-seat turboprop aircraft whose runway slot allocations are being squeezed by airport congestion.

A US Government agency endorsement would give the S-92 a major boost in the eyes of potential overseas buyers, and so Sikorsky is pursuing a number of emerging domestic opportunities. These include finding successors for the US Air Force's HH/MH-60G Pave Hawk combat search-and-rescue (CSAR) machines and possibly the US Navy's heavylift vertical onboard delivery CH-53Es, as well as the US Coast Guard's Deepwater project.

VIP role

The S-92's 1.83m (6ft) high cabin and Honeywell auxiliary power unit make the helicopter ideal for head of state/VIP transport and Sikorsky claims to have already submitted several such proposals. Thailand is known to be looking for a new royal flight helicopter and the US Marine Corps has taken the first steps towards finding a VXX replacement for the US President's Sikorsky VH-3Ds (Flight International, 4-10 July, P20).

Among shorter-term prospects is a pending Portuguese order for eight to 12 new SAR and two fishery protection helicopters for delivery between 2002 and 2006. Tenders were submitted last October, with the S-92 pitted against the EH Industries EH101 and a proposed five-bladed version of the Eurocopter AS532 Cougar Mk2Plus.

The Portuguese air force has set exacting mission requirements based on a 740km radius mission, a 30min out of ground effect hover to rescue survivors, and return with 30min of fuel in reserve. Sikorsky validated the S-92's performance to the Portuguese in April during a series of flight demonstrations from its West Palm Beach test facility.

"For the Portuguese mission, we're putting extra fuel into two 230gal [870 litre] drop tanks on each side of the sponsons," says Thomason. "Because it's a really heavy load, it's useful in the event of an engine failure on take-off to be able get rid of the fuel instantly. There is also a cabin installation for two 185gal tanks for those that don't need that much fuel and want lower drag."

Sikorsky plans to certify the S-92 up to an initial maximum gross weight of 11,570kg (25,500lb), based on a 19-seat, 740km payload range performance. Military qualification of the 22-seat utility version is offering an alternate growth weight of 12,850kg. The helicopter has flown at over 13,620kg to meet a Portuguese overload requirement and Thomason adds: "I'm sure the helicopter will grow to that as a basic mission requirement."

Power jump

The S-92's installed power has already jumped from the 1,510kW (2,030shp) rated CT7-6D turboshaft fitted to the first flight prototype to the uprated 1,860kW CT7-8 selected for all subsequent machines. Rolls-Royce Turboméca has been promoting its larger RTM322 as offering further growth potential of up to 2,235kW, particularly for hot and high conditions.

"That is an option that offers some interesting features," says Thomason. "For initial production, we're going to stick with the CT7-8, but we're aware of the capability of the RTM322 and compatibility with the S-92 and we're going to keep an open mind with respect to what the customer requires for that particular engine."

GE is almost certainly planning its own growth strategy based on either a further development of the CT7/T700 series, or an all-new centreline engine competing for the US Army's planned Common Engine Programme. Given Sikorsky's flight test schedule and the likely need to uprate the S-92's 3,110kW-rated dual engine transmission to take a larger engine, it will not be reality before 2006 at the earliest.

The S-92 is expected to be demonstrated this summer to the four nations in the Nordic Standard Helicopter Programme (NSHP). In April, Sikorsky submitted a bid for an all-encompassing package of 73 machines to replace Denmark's SAR S-61s, Finland's Mi-8 troop transports, Norway's shipboard GKN Westland Lynxes and Sweden's Kawasaki/Vertol kV-107 land-based anti-submarine warfare (ASW) helicopters, starting in 2003.

Closely following NSHP is a tender submitted to Oman in June for up to 50 troop transport and SAR helicopters. In anticipation of Canada kick-starting its Maritime Helicopter Project (MPH) later this year, Sikorsky has teamed with Bombardier. Elsewhere, it is manoeuvring to compete for a Japanese Antarctic support, SAR and airborne mine countermeasures helicopter replacement programme.

Sikorsky has conducted a series of computer-aided designs and mock-ups of the helicopter equipped with an array of different mission systems, such as a search radar, forward-looking infrared imager and dipping sonar. NSHP feedback has also led Sikorsky to modify the S-92's overall design by adding a 400mm (16in) plug aft of the cockpit, cropping the vertical tail by 1.04m and moving the horizontal stabiliser forward from the upper left side of the tail to the lower right.

The increase in cabin structural weight is partially offset by the smaller, lighter tail, the net benefit of which is flatter attitude in hover transition and easier shipboard stowage - a key NSHP requirement. "There was a nose-up tendency-the change moves the helicopter's centre of gravity forward and also enables us to put a 50in [1.3m] door on the aircraft for the folks who want to use the S-92 for SAR," says Thomason.

The 200mm wider door will come with a choice of a hinged clamshell configuration with lower airstairs for airline operations, or a 1.8m high sliding door to allow for an overhead rescue hoist for SAR missions, and the option of a bubble window. The longer fuselage has room for an extra row of seats in the civil S-92, but this would cost an extra attendant.

Earlier in the year, Sikorsky announced a decision to replace the five Sanders avionics suite displays with a Rockwell Collins avionics system based around MFD-268EP screens. Because of these changes, Sikorsky has had to extend its 1,300h flight test programme, delaying initial US Federal Aviation Administration FAR Pt 29 certification until early 2002.

First delivery

The first helicopter is set for delivery to Cougar in mid-2006. "We have to follow very quickly with Transport Canada certification to support Cougar and because the North Sea is very likely to be an application for the helicopter, then Joint Aviation Authorities JAR 29 becomes necessary almost right away as well," says Thomason.

By mid-June, Sikorsky had logged 324h flying time, while the ground tiedown vehicle had completed a 200h drive system qualification. The first flight test helicopter will resume flying in August equipped with the new horizontal stabiliser and will be joined by a third stretched machine at the year-end. A final pre-production machine will fly early next year with new avionics, enlarged fuselage and reconfigured tail.

The company has mapped out a relatively conservative schedule for ramping up production, with only five machine set for delivery in 2002 and 20 the year after. "We want to watch the first aircraft very closely and establish if there are any remaining problems to fix or improvements that can be made early on," says Thomason. "After the first two years of production, it's kind of who wants some?"

Source: Flight International