OVERVIEW

The SM-74 is an Advanced Twin Turboprop Regional Airliner Concept presently undergoing consideration to enter into full scale development and engineering design by Stavatti Commercial Aerospace as a corporate sponsored, commercial initiative to meet anticipated future Commercial Regional Airliner and STOL transport needs. A new type of Regional Airliner specifically engineered for Short Field operations, the SM-74 will permit airlines to operate from a diverse array of locations including, rural mainland Asia, the rual inland Indian Subcontinent, rural Inland Africa, a diverse array of Central American and South American airstrips, the Canadian Northwest, Alaska, previously hard-to-service Caribbean and Pacific Rim Islands/atolls and nearly all rural regions with short runways that ordinarily require steep approaches. Particularly well suited to operate under practically all climate types, including hot and high zones, the SM-74 is a high capacity airliner that enables swift departure from nearly any location during most weather conditions. Envisioned to significantly improve the capabilities of Regional Airlines and Major Air Carriers alike, the SM-74 will enable route expansion on a global basis, requiring under 2,500 ft for take-off and landing at Maximum Take-Off Weight (MTOW).

Featuring an elliptical section fuselage proven in the SM-73, the SM-74 offers wide-body comfort to regional passengers, providing a main cabin that is 13 ft 10 inches at the floor and 15 ft 6 inches at its widest point. With a range of 1,400 nm to over 2,000 nm, the SM-74 will serve as a economical medium-range airliner that provides passenger comfort levels commensurate to that associated with large body commercial turbofans including the Boeing 737 and 757. Delivering a high performance cruise speed of over 400 kts at altitude, the SM-74 is faster than either the ATR 72-500 (276 kt cruise) or the Bombardier Q400 (360 kt cruise) and is only 47 kts slower than a typical Boeing 737. Bridging-the-gap between Regional Turboprop and Medium Range Turbofan Airliners, the SM-74 paves a new paradigm focused upon efficient, comfort oriented flexible transportation.

The SM-74 is the Regional Airliner component of Stavatti's SM-70 family of military transport, anti-submarine warfare and regional commercial transport aircraft. A series of fixed wing, twin engine turboprop aircraft that benefit from a common wing, empennage and powerplant arrangement, the SM-70 series includes the SM-72 Medium Transport, the SM-73 Rigel™ Anti-Submarine Warfare/Maritime Multi-mission Aircraft (ASW/MMA) and the SM-74 Turboprop Regional Airliner (TRA). The SM-74 would likely be manufactured at a single production facility and may enter Low Rate Initial Production (LRIP) between 2014 and 2018. The SM-74 program is managed by Stavatti Commercial Aerospace.

ACCOMMODATION

The SM-74 has a crew of four to five including a two person flight crew consisting of a Pilot and Copilot accompanied by two to three cabin attendants. The aircraft interior is composed of a flight deck, a forward cabin which includes a galley and lavatory, a main passenger cabin with seating for between 88 and 112 passengers and an aft cabin which includes a lavatory, aft galley and lounge. The flight deck and cabins are pressurized to an equivalent 6,000 ft altitude. Interior access is provided by port fuselage forward and aft cabin doors, port and starboard emergency exit hatchess and a secure, nose gear wheel well hatch with access ladder to enable alternate flight crew access.

Engineered for elegant integration into existing commercial airline infrastructures, the SM-74 fuselage consists of two sections separated by a 6-inch thick main cabin floor: the main cabin and a spacious cargo hold/baggage bay located below the main cabin in the aircraft belly. The main cabin is 74 ft long and includes a 57 ft long passenger area. Total main cabin floor area is 895 sq ft with a corresponding volume of 6,688 cu ft. Envisioned to provide regional passengers with an unprecedented sense of comfort and satisfaction, the standard SM-74 cabin configuration includes six seats per row consisting of two modern triple seat sets separated by a 24-inch center aisle. Each seat is 22.5 inches wide and is set at a 41 inch pitch in the First Class configuration. Offering full recline and digital integration for active passengers, the standard SM-74 may be populated by 14 First Class rows resulting in a standard passenger load of 88.

POWERPLANT

The SM-74 is powered by two 14,500 SHP D-27 turbopropfan free turbine propulsion engines with a shaft output of 950 RPM. The propulsion engines drive two 17 ft 6 in diameter, eight bladed propellers. The propulsion engines drive an integrated auxiliary axial flow compressor that interfaces on-demand with the propulsion engines through a clutch in the engine gearbox. When the CCW system is engaged, the compressors draw approximately 31% of the SHP from the propulsion engines for the purpose of producing compressed air to supply the aircraft CCW/BLC system.

The turbine propulsion engines are mounted, one per wing, in a tractor configuration whereby the tip of the propeller is located immediately aft of the wing channel‘s trailing edge, with the wing channel approximately the same radius as the propeller. This propeller location/engine arrangement is a principal element of the lift enhancing, channel wing configuration. The turbine propulsion engines are housed in individual nacelles featuring an extended nacelle boom/aft section. This provides additional volume to house the CCW compressors and electronic countermeasures and avionic systems. Individual nacelles are supported vertically by engine support pylons mounted ventrally to the nacelles and supported directly by landing gear support sponsons integrated into the wing channel.

The D-27 turbopropfan, designed by ZMDB Progress of Zaporozhye, Ukraine and produced by OAO Motor Sich Joint Stock Company (JSC), presently powers the Antonov AN-70. D-27 design began in 1985 with the AN-70 prototype rolling out in 1992 and the AN-70 first flight occurring in 1994. To enhance SM-70 series performance, it is likely that an Improved Performance Derivative D-27 (IPD D-27) will be produced specifically for the Stavatti application either entirely by Motor Sich, or through a Joint Venture company involving Motor Sich in partnership with a United States turbine engine manufacturer. A U.S. joint venture partner for IPD is not yet negotiated, however, potential candidates include a new company formed specifically by Stavatti Heavy Industries, Ltd., in joint venture with Motor Sich to produce IPD D-27 engines in the U.S. The IPD D-27 Turbopropfan will build upon the success of the proven D-27 powerplant, while increasing overall powerplant performance to create a propulsion system that develops a maximum of 15,000 to 18,000 SHP.

FLIGHT DECK

The SM-74 features a cockpit designed for two-person, human-centered, reduced workload operations. The flight deck design accommodates a wide spectrum of male and female crewmembers encompassing the 1st percentile female through the 99th percentile male (NATO) population range, corresponding to crewmembers ranging from 5 ft 4in/100 lbs through 6 ft 4 in/250 lbs.

Employing a traditional yoke, full deflection rudder pedals, and FADEC engine control system, the SM-74 panel features redundant, dual instrumentation and displays. The primary pilot flight reference instrument is a Honeywell-produced derivative of the Primus Epic Integrated Avionics system that includes a total of six 10 x 13 in multi-functional Liquid Crystal Flat Panel Displays with Integrated Primary Flight Display (IPFD) and Integrated Navigation (INAV) technology. To interface with the Primus Epic system, a side-mounted cursor control system and keyboard interface is provided for the pilot and co-pilot. The Honeywell Visual Guidance System Head-Up Display (VGS HUD) offering a 25 x 30 degree field of view is provided for both the pilot and co-pilot. For in-flight emergencies, all SM-70 series aircraft are equipped with stand-by analog instruments including attitude and airspeed indicators as well as an altimeter, HSI, and clock.

Cockpits are designed for day/night VFR/IFR operations and are Generation IV night-vision compliant. With avionics integrated about a MIL-STD-1553B interface/data bus, all SM-70 series models feature additional avionic and sensor systems appropriate to their mission profiles. For crew comfort, the cockpit is pressurized to 6,000 ft equivalent atmosphere at altitude with standby crew oxygen provided by a Carlton OBOGS.

STRUCTURE

The SM-74 is of fail-safe, semi-monocoque construction composed of an alloy internal substructure consisting of Titanium load bearing elements with Aircraft Aluminum and Graphite Reinforced Plastic (GRP) as load-bearing stressed external skins and Kevlar Reinforced Plastic (KRP) secondary structural skins. Approximately 46% of the aircraft structure is composite by weight, with the remaining 54% is advanced aerospace alloys Approximately 34% of the SM-74 primary structure is GRP, while 10% is KRP. Principal composite materials employed throughout the SM-74 structure include Hexcel IM-9 Graphite Fiber/Polyimide Resin as the GRP and Dupont Kevlar/Polymer Resin as the KRP. The primary Polyimide resins employed include high-temperature, autoclave cured RP46, BIM-AC non-mutagenic/non-carcinogenic polyimide, AMB-21polyimide or DMBZ-15 polyimide.

A significant number of aircraft components are made from Titanium, which totals 22% of the aircraft structural weight. Chosen due to its high strength to weight ratio and resistance to galvanic corrosion when fastened to composite materials, titanium components are produced using laser forming, laser machining and traditional aerospace Titanium part production methodologies. Aluminum alloys constitute approximately 33% of the aircraft primary structure by weight, with principal aluminum alloys employed including Alcan/Alcoa produced aluminum alloys such as 7150-T7751 Aluminum, 7075-T651 Aluminum, 7055-T7751 Aluminum and other high performance aircraft aluminum.

The SM-74 benefits from advanced structural manufacturing techniques where primary alloy structural members including fuselage frames and ribs are unitized, single-piece construction produced by Stavatti qualified Industry Team Members. Individual alloy structural members, including primary spars, ribs, longerons and frames are mechanically fastened together using rivets or bolts or welded using inert/laser processes. Composite materials are mechanically fastened to the alloy substructure using rivets, bolts and proprietary fastening systems, or alternatively, co-cured to high temperature titanium elements during the component autoclave cure cycle. The SM-74 features no bonded components.

The SM-74 is designed for a maximum limit load factor of +4.5/-2.0 at MTOW. The composite and corrosion resistant alloy construction offers a minimum 40-year service life corresponding to approximately 60,000 flight hours.