Sikorsky S-92 – Igor I Sikorsky Historical Archives (2024)

Background

The S-92 Helibus was designed and developed during the 1990 decade to serve as both a commercial passenger carrier and as a military troop/cargo carrier. Its initial design was intended to take advantage of the both the proven technologies of the Black Hawk models as well as the four million flight hours accumulated on the H-60 series at that point in their history. The H-60 dynamic system in particular had reached a proven high level of durability as a result of this extensive operating service experience. However, the initial design of the S-92 using the then existing H-60 propulsion and dynamic systems mated to an enlarged fuselage proved to be too limited in useful load capability. This limitation was created by a combination of the higher weight of a new airframe designed to carry 19 passengers and to the structural limitation of a 22,000 pound gross weight imposed by the existing H-60 dynamic system.

Because these limitations imposed too great a penalty on speed and range performance, the decision was made to redesign and upgrade the basic H-60 dynamic system where needed to achieve a mission gross weight closer to 25,000 pounds while at the same time designing the dynamic components to meet newly issued FAA requirements regarding damage tolerance for commercial helicopters. That effort was so successful that Sikorsky was awarded the 2002 Collier Trophy by the National Aeronautics Association acknowledging its achievements in safety, operating cost and traveling comfort. The S-92 design benefited from many new technologies that together represented a new helicopter generation. Chief among these were the advanced rotor blade that employed improved airfoil design and blade tip configuration as well as a fully composite material spar and a fully damage tolerant main rotor head design. In addition, Sikorsky’s new Active Vibration Control System provided much reduced vibration levels throughout the operation aircraft and rotor speed ranges. Significant cockpit display system improvements helped improve aircraft safety and reduced pilot workload. The reader should note that the S-92 and its derivative models were still in production at the time that this model history was prepared. As a result, changes to the design, equipment, features, weights and performance described herein are likely to take place as this model becomes further developed and improved.

The Sikorsky S-92 commercial model was unveiled at Heli-Expo ’92 in Las Vegas, Nevada on March 22, 1992. The mockup had a 19 passenger airline style interior and a five-tube (each eight by seven inches) Honeywell Electronic Flight Information Systems (EFIS) flight deck. The mockup was fitted with a new rotor that was based on the UH-60 BLACK HAWK. Offshore oil exploration was the primary target for the S-92. Scheduled airlines and general utility duties were also being targeted. A 23 seat military version of the proposed helicopter, a growth derivative of Sikorsky’s H-60 family, was also being shown to potential customers in full size model form.

A decision on the future of the S-92 would be made by the end of this year. The required Customer interest did not develop and in 1993 Sikorsky postponed launching the S-92 due to the international helicopter market downturn and instead began searching for international risk sharing partners.

Team S-92

A new era began June 12th 1995 at the Paris Air Show with the formal launch announcement of the full scale development of the Sikorsky S-92 HELIBUS™ with six international team members. Full scale development of the S-92 commenced.

Serving as the leader of Team S-92, Sikorsky designed and manufactures the aircraft’s dynamic systems and carried out final assembly, flight test, and certification. Each international partner performed the detail design work for its section of the aircraft based on basic data supplied by Sikorsky. Partners were responsible for all tooling planning and tooling, and provided 5 prototype shipsets, specific test pieces, and all required spare parts to support the flight test program. Members included the following risk sharing partners:

• Japan’s Mitsubishi Heavy Industries (7.5% – main cabin)
• Spain’s Gamesa Aeronautica (7% – main rotor pylon, tailcone/transition section and composite interiors),
• Peoples Republic of China’s Jingdezhen Helicopter Group (2% – tail pylon and horizontal stabilizer)
• Taiwan’s Aero Industrial Development Corporation (AIDC) (6.5% – Cockpit Structure)
• Brazil’s Embraer (4% – sponsons complete with fuel system and landing gear).

Telecommunications between partners played a vital role for Team S-92. A satellite communications network linked all partners. Three-dimensional electronic models were posted by the Sikorsky drawing release system over the network. All drawings were digital CATIA (Computer Aided Three-dimensional Interactive Application) drawings with real time interface with all partners. To assist in the development and manufacturing processes for the separate sections of the helicopter, Sikorsky personnel were stationed with each of the international partners. Each team was assigned an On-Site Partner Manager plus quality assurance, operations, logistics, manufacturing engineering, and various engineering design and analysis staff members as required. Complementing the international efforts of our partners were the Integrated Product Development (IPD) Teams based at the Sikorsky Stratford, Connecticut Facility. The IPD Teams were responsible for the aircraft’s dynamic systems, electrical/electronic systems, systems engineering, systems integration and test.

The major subcontractors were General Electric (CT7-8D turboshaft engines), Rockwell Collins (Avionics Management System (AMS)), and Hamilton Sundstrand (Automatic Flight Control System (AFCS)).

Sikorsky built five prototype S-92s, one for ground testing and four flight test aircraft.

• #1 aircraft, the ground test vehicle, was scheduled for 350 hours including 200 hours to certify the main gearbox.
• #2 aircraft, the first flight aircraft, was scheduled for 340 hours of flying
• #3 aircraft was closest to the production aircraft and focused on the aircraft’s operating systems. These systems included the auxiliary power unit, the engines Full Authority Digital Electronic Controls (FADEC), Automatic Flight Control System (AFCS) and engine development.
• #4 aircraft was the acoustics and options development platform and scheduled for 124 hours of flying.
• #5 aircraft, a utility configured aircraft was scheduled for 480 hours of flying at maximum gross weight and external load testing

The first flight was on December 23 1998 at the Sikorsky Development Flight Center in West Palm Beach, Florida. The 50 minute maiden flight consisted of 8 takeoffs and landings including hover, forward, and sideward flight maneuvers.

As originally envisioned the S-92 was to combine upgraded dynamic system components of the H-60/S-70 series with a larger cabin. However, in order to provide competitive performance in the commercial market, the S-92 is essentially an all new helicopter, with larger, composite construction, swept, tapered and anhedral tipped main rotor blades, new tail rotor, and a new four stage transmission based on the three stage S-70 unit.

Some 40% of the aircraft was of composite construction. The S-92’s main cabin was wider and longer than the S-70’s and featured a rear loading freight ramp, while the cockpit featured a Rockwell Collins EFIS system with four color liquid crystal displays, with provision for a fifth. Power was from two FADEC equipped General Electric CT7-8D turboshaft engines.

Design changes announced in July 2000 in response to customer requests included a 16 inch increase in cabin length aft of the cockpit to permit installation of a 50 inch wide cabin door to improve hoisting capability and to accommodate a Stokes litter during SAR operations; reduction in the length of tail rotor pylon by about 41 inches to offset additional weight of cabin extension; and the horizontal stabilizer was repositioned from the left side opposite the tail rotor to the right side at the base of the tail rotor pylon. These changes provided additional benefits in creating an improved fold configuration for shipboard operations, increased bird strike protection deriving from the relocation of tail rotor drive shaft and controls aft of the tail spar, and a flatter hover attitude arising from a forward shift of the helicopter center of gravity, improving visibility for confined space and shipboard landing, and increasing aft fuselage ground clearance. The revised configuration was incorporated from the third prototype and on all production aircraft.

Configuration Features

Advanced Cockpit and Onboard Systems

The S-92 cockpit features a Rockwell Collins avionics package that displays flight-critical data on six-inch by eight-inch, color, liquid-crystal, multifunction displays and includes dual flight-management systems with integrated control of the flight director. The instrument panel was reduced in width, compared with earlier designs, to improve the pilots’ field of view. Situational awareness also can be enhanced through the addition of weather radar data with a flight path overlay, a forward-looking infrared (FLIR) system and a digital moving map. The cockpit is night-vision-goggle-compatible and can simulate one engine-inoperative conditions for training purposes. Other key cockpit systems include an Engine Indicating Caution Advisory System (EICAS) and a Honeywell Enhanced Ground-Proximity Warning System (EGPWS).

General Arrangement Drawing

S-92 Optional Equipment

General Characteristics and Performance

Production History

The first S-92A was delivered to PHI, Inc. of Lafayette Louisiana on September, 27, 2004. By early 2012 over 150 S-92A helicopters have been delivered to customers worldwide with 400,000 total flight hours. Production is ongoing.

• byVinny Devine