OVERVIEW
The SM-27 MACHETE is a single engine Close Air Support (CAS), COunter-INsurgency (COIN) and Advanced Trainer (AT) military aircraft currently under development by the Military Aerospace Division of Stavatti Heavy Industries, Ltd. The Machete will be produced in at least five derivative variants including:
• SM-27S Single Seat, Single Engine Turboprop
• SM-27T Two Seat Tandem, Single Engine Turboprop
• SM-27J Single Seat, Single Engine Turbofan
• SM-27L Two Seat Tandem, Single Engine Turbofan
• SM-47S Single Seat Forward Swept Wing Fighter
• SM-47T Two Seat Forward Swept Wing Fighter
The SM-27S/T Machete is a single engine, turboprop aircraft which will be produced in manned, as well as unmanned/remote pilot-in-the-loop and unmanned autonomous configurations. The SM-27S/T will be produced in two variants: The SM-27S and SM-27T. The SM-27S is a single seat, high performance light attack and COunter INsurgency (COIN) platform. The SM-27S is designed specifically for Close Air Support (CAS), and in addition to COIN, can satisfy a host of air missions including Light Attack (LA), Counter-Terrorism (CT), Forward Air Control (FAC) and Armed Reconnaissance (AR). The SM-27T is a two place tandem weapon system which can not only satisfy the COIN, CAS, FAC and AR role, but also serve as an Advanced Trainer (AT).
Power for the SM-27S/T is provided by a 3,000 SHP class free turbine engine powerplant driving a contra-rotating propeller. Powerplant airflow is supplied by laterally mounted, bifurcated fuselage flush inlets.
A comprehensive integrated avionics suite, including Electronic Warfare/Electronic Counter Measures (EW/ECM) is featured. Stores and ordinance is carried on eight wing hardpoints with standard NATO 14-in suspension. Typical fixed internal armament includes a single ventrally mounted 30mm cannon with up to 675 rds of 30mm ammunition (SM-27S) or 470 rds of 30mm ammunition (SM-27T).
The SM-27S/T will be qualified at the AFFTC at Edwards, AFB. The SM-27S/T will be certified to applicable FAA type and production certification standards (FAR 25, etc.) as a fully qualified Day/Night VFR and IFR (VMC/IMC) aircraft.
ACCOMMODATION
The SM-27S/T cockpit is designed to accommodate a wide spectrum of male and female crewmembers encompassing the 1st percentile female through the 99th percentile male (NATO) population range. This population range corresponds to crewmembers ranging from 5 ft 4in/100 lbs through 6 ft 5 in/280 lbs. For planning and engineering development purposes, assumed standard crew-member weight is 260 lbs, including survival equipment.
The SM-27S flight crew consists of a single pilot seated on a Martin Baker MKUS.16L zero/zero ejection seat. The SM-27T flight crew consists of a pilot and Weapon Systems Officer (WSO)/Observer seated in tandem (fore and aft crewstations respectively) on Martin Baker MKUS.16L zero/zero ejection seats in satisfaction of the COIN/CAS/FAC role. In satisfaction of the Advanced Trainer role, the SM-27T flight crew consists of a student and instructor seated in tandem (fore and aft crewstations respectively) in on Martin Baker MKUS.16L zero/zero ejection seats. Total standard SM-27T crewmember weight, including survival equipment, is 520 lbs.
The PW127G drives two contra-rotating, 120 in diameter reversible-pitch, constant speed propfan blades of Scimitar form. The forward propeller features 8 blades while the aft propeller is of 6 blade design to ensure harmonic balancing of the engine system. Totaling twelve pusher blades, each blade is fitted with EESS for deicing.
The PW127G is orientated in a pusher configuration, mounted to the aircraft via Titanium engine mounts with the engine bay segregated from the fuselage by a Titanium firewall. The engine itself is enclosed in an armored clamshell cowling consisting of Spectra®/Polymer Resin. Engine bay fire suppression is provided by an integrated Kiddie detection and suppression system.
The standard SM-27S/T cannon is the General Dynamics GAU-13/A 30mm derived from the GAU-8/A. The GAU-13/A is a four barrel, pneumatically driven cannon with a rate of fire of up to 2,400 rds/min. The GAU-13/A employs standard 30mm PGU-13 (HEI) and PGU-14 (API) ammunition with a muzzle velocity of 3,600 ft/sec. In the SM-27S, the cannon may be provided with over 675 rounds of additional ammunition contained within an expanded ammunition drum located aft of the forward cockpit. In the SM-27T, a rectangular ammunition magazine located directly behind the aft crew station provides a total of 470 rds.
The Machete is designed primarily for air-to-ground missions, employing ordinance such as the AGM-65, GBU-39/B, GBU-31, GBU-32, GBU-38, CBU-97, CBU-59, BLU-107 and additional stores. Optimized for precision strike, the SM-27S/T employs GPS guided munitions, including the GBU-39/B Small Diameter Bomb (SBD) to dispatch ground threats with minimal collateral damage. The SM-27S/T can carry up to 24 GBU-39/Bs, or 8 AGM-65s or 2 GBU-31 JDAMS externally in addition to 2 AIM-9s.
Air-to-Air capability is provided through the carriage of AIM-9 and similar passive homing/IR AAMs. The Machete is capable of LANTIRN, LITENING and ECM pod carriage and employs a MIL-STD-1760 Weapon Interface Data Bus. Weapons release is conducted through a control column gun trigger switch and weapon release button for air-to-air/air-to-ground. An abridged SM-27S/T stores loading chart is provided:
SM-27S/T avionics are integrated about a MIL-STD-1553B Interface/Data Bus with Data Bus wiring used throughout the system architecture to reduce wiring bundles. The SM-27S/T features a comprehensive navigation/communications suite. The philosophy driving the SM-27S/T avionic configuration emphasizes mission completion, reliability, flexibility and ease of serviceability. Avionics may be of a variety of types including either COTS or MOTS. Wherever possible, avionics are of modular LRU type with BIT. Principal avionics and sensors are contained in two to three bays including the nose radome/sensor bay, forward fuselage avionics bay and aft cockpit avionics bay as available in the SM-27S.
The avionics/sensor suite is designed and integrated by Stavatti based upon customer specifications. Stavatti has developed a Standard (NATO Export) Avionics/Sensors Configuration which includes a variety of proven, reliable systems from which NATO end-users may select a specific Machete configuration. This Standard configuration is optimized to permit unrestricted export of the Machete via Direct Commercial Sales (DCS) to the majority of NATO members, although specific avionics, including GPS with PPS, as well as particular COMSEC/TEMPEST equipment, must be procured via FMS or on a government-government basis. Principal sensors and avionics included in the Standard Configuration are:
• Lockheed Martin AN/APG-67(F) Multi-Mode Pulse Doppler Radar mounted in the forward Radome
• The Raytheon AN/AAS-52 Multi-Spectral Targeting System.
A detailed listing of principal avionics and sensors which are included in the typical Machete configuration is provided on the SM-27S/T Machete Performance & Specifications webpage.
The cockpit is equipped with a Cockpit Video Recording (CVR) system capable for recording at least 120 minutes of HUD symbology, the external HUD field of view, cockpit LCD MFD symbology and all aircraft communication system audio. The aircraft is also equipped with a crash survivable Flight Data Recorder (FDR) capable of storing the last 90 minutes of flight data for post-crash flight reconstruction. The aircraft is fitted with a Crash Position Indicator (CPI) and a survivable Underwater Locator Beacon (ULB). Halon 1301 is employed for avionic system fire suppression within sealed avionic bays.
COCKPIT
The cockpit is available in two configurations: the single seat SM-27S and the two seat tandem SM-27T. Each configuration is designed for reduced workload operations with crewmembers seated on unreclined Martin Baker MKUS.16L ejection seats. Both Machete models incorporate auto-eject and auto-eject sequencing. The cockpit is pressurized to 8,000 ft and air-conditioned. Standby crew oxygen is provided by a Carlton OC1132 Molecular Sieve Oxygen Generating System (MSOGS).
The cockpit for SM-27S/T is a completely modular unit, produced as a unitized, self contained system external to the fuselage. Incorporating distinct, armored and EM hardened quick interconnects for flight controls, electrical junctions, avionics buses and environmental control, the Machete cockpit is installed and extracted vertically in the absence of the bubble canopy. Cockpits for either model attache to the CAM bath-tub structure through bolts in vibration damping fittings.
The CAM, featuring armor plate and Spectra® fiber significantly mitigates the penetrative effects of projectiles and spall. Cockpit modules are interchangeable, allowing a specific aircraft to be converted to either a single seat or two place tandem variant.
The aircraft bubble canopy is of large area, frame-less, single-piece clamshell type. The canopy is of advanced bullet resistant polycarbonate composition and can safely sustain the impact of a 4 lb bird at airspeeds exceeding 450 kts from any attitude. Visibility is 350° azimuthal with 13° over-the-nose and 25° over-the-side. The canopy is hydraulically lifted upward for cockpit access. The canopy is defrosted and purged of precipitation using a perimeter high pressure, powerplant bled, hot air system. An internally mounted, manual unlatch and hand-crank is provided.
The primary visual flight reference display is the CMC Night Hawk wide field-of-view HUD and HUD repeater system. Secondary flight reference instruments include the customers choice of LCD MFD configurations including five L3 Communications Actiview 104P 6 x 8 in LCDs. A VSI Integrated HMDS may be used as an alternative to the HUD for the forward crew station.
The aft panel of the SM-27T is largely identical to that of the forward panel, with exception of the HUD being replaced by a HUD repeater. IFR certified, the cockpit is designed for Generation III night vision compliance and Helmet Mounted Cuing Systems/Integrated Helmet and Display Sighting Systems (HMCS/IHDSS). Forward and rear panels are complemented by a comprehensive warning annunciator panel, two 3-axis air conditioning/heater vents and standby instruments.
The forward panel of the SM-27S/T smoothly integrates the Machete HUD, MFDs and standby instruments. A conceptual Cockpit Arrangement and layout drawing is provided:
The SM-27S/T employs an internal Electronic Counter Measures (ECM) suite. The SM-27S/T EW system accommodates a wide variety of external jamming pods and countermeasures dispensers and includes Radar Warning Receivers, Laser Warning Systems, Self Protection Jammers and Advanced Missile Warning Sensors. The ECM suite is designed and integrated by Stavatti based upon customer specifications. Stavatti has developed a STANDARD (NATO EXPORT) ECM/EW CONFIGURATION which includes demonstrated as well as next generation electronic warfare systems which may equip Machete.
This STANDARD configuration is designed to satisfy the needs of the majority of potential NATO customers without export restriction, however, particular ECM systems must be procured on an FMS or government to government basis. Typical SM-27S/T ECM systems include:
• 14 AN/ALE-47 Countermeasures Dispensers of USAF style
• The ATK AN/AAR-47 Missile Warning System
A complete listing of additional ECM systems which are included in the STANDARD Machete configuration is provided on the SM-27S/T Machete Performance & Specifications webpage.
STRUCTURE
SM-27S/T primary structure is an amalgamation of composite and advanced alloy materials. By weight, 23% of the aircraft structure is composite material, 63% is advanced alloy and 14% is polycarbonate and other non-metallic materials.
Approximately 14% of the aircraft structure is comprised of Hexcel IM9 graphite fiber suspended in a matrix of hi-temperature polyimide resin, also known as Graphite Reinforced Plastic (GRP). Graphite composite components include primary structural members such as fuselage skins, vertical stabilizer skins, horizontal stabilizer skins, flaps and flight control surfaces.
Nearly 4% of the aircraft structure consists of Dupont Kevlar® 149,129 or 29 aramid fiber suspended in a matrix of epoxy or polymer resin, refered to hereafter as Kevlar Reinforced Plastic (KRP). Approximately 4% of the aircraft structure is composed of Honeywell Spectra® 2000 fiber of 650 and 1,200 denier employed in a ballistic capacity or suspended in a matrix of epoxy or polymer resin, hereafter referred to as Spectra® Reinforced Plastic (SRP). KRP and SRP composites are used within the aircraft fuselage structure as a secondary structure and as a discrete ballistic armor. KRP and SRP are used as the primary structural material for radome, antenna fairings, support and access panels, engine cowling and in discrete armor throughout the aircraft.
Approximately 6% of the aircraft structure consists of Alcoa produced aluminium alloys including 7150-T7751 Aluminum, 7075-T651 Aluminum, 7055-T7751 Aluminum and other high performance aircraft aluminum. Aluminum is used in the aircraft wing skins, canard skins, vertical stabilizer skins, fuselage and landing gear structure.
Over 57% of the SM-27S/T structure is composed of Titanium alloys including the general purpose Ti-6Al-4V Titanium, SP 700 Titanium, Ti-15V-3Cr-3Sn-3Al, and Ti-6Al-2Zr-2Sn-2Mo-2Cr-0.25Si (Ti-6222) Titanium for airframe structural elements.
Additional composite materials used throughout the aircraft include Hexcel IM7/polyimide, Kevlar®-49/epoxy, Kevlar®-29/epoxy, Kevlar®-129/epoxy and Spectra® 1000/epoxy. These and other alloys and composite materials constitute over 5% of the SM-27S/T structural weight. 9% of the remaining SM-27S/T structural composition consists of the transparent polycarbonate material used in the Machete clamshell bubble canopy.
The SM-27S/T is designed for an operational service life of 15,000 hours, accumulating an average of 750 hours per annum. Aircraft fatigue life will be based upon 30,000 takeoffs and landings (cycles). The aircraft maximum design load factor limit is +7.5g and -3.5g at Maximum Gross Takeoff Weight (MTOW) with maximum external stores.
FUSELAGE
The Machete fuselage is a compact unit consisting of the fuselage core, radome and engine cowling. The fuselage core is a unitized frame structure consisting of a Titanium and Aluminum sub-frame. This subframe employs the structural principals pioneered in highly survivabile aircraft including the B-17 and A-10. The alloy subframe is a laser welded and built-up structure which serves as a rigid chassis for the integration of all alloy frames, primary bulkheads, mounts and the firewall. All fuselage contained systems, including avionics, electrical, armament hydraulic and the CAM, are secured to subframe integrated alloy mounts. The subframe is skinned in an alloy film to ensure all TEMPEST sensitive avionic and electrical systems are contained within a Faraday cage.
The Machete fuselage features the Cockpit Armor Module (CAM) for integrated cockpit protection. The Machete fuselage features an integrated armored ammunition cell and internal self-sealing fuel tanks. The fuselage incorporates discrete armor throughout. The fuselage features a starboard located downward hinged door with integral steps for crew ingress/egress.
The radome is composed of bandpass composites and hinges to the port for radar/avionics access. The engine cowling is of three-part clamshell type and is composed of a Kevlar® (KRP) composite sandwich.
SM-27 Machete wings are of high aspect ratio, low-wing, cantilever type. Wing leading edge sweep is 5° and trailing edge sweep is -5°. Wing span, excluding wing-tip dispensers/winglets is 47 ft 0 in. Reference wing area is 243.4 sq ft. Wing aspect ratio is 9.08. The wing airfoil is a modified NACA 65(2)-415 throughout the span. To alleviate the negative affects of tip stall, the Machete wing employs approximately 2° washout. Wing incidence is 0°. Wing dihedral, from root, is 2°. Wing Drag Divergent MACH Number is slightly above 0.73 MACH (483 Kts at sea level).
The Machete wing is a modular, three-piece, fail-safe structure consisting of an integrated center section spanning 149 in and port and starboard outer sections spanning 208.25 in each. The center section consists of two sine wave Ti-6222 spars which form the basis of a rigid, laser welded, Titanium carry-through box. This carry-through box serves as mount and armored housing for the main landing gear. The carry-through box is also the principal mount and interface for port and starboard Titanium monocoque empennage support booms which serve as the structural interface for the vertical and horizontal stabilizers. The center section has Titanium ribs, stringers and skins. All alloy components are fastened via laser welding and flush rivets (Ti-Matic).
The aircraft canard foreplanes are fixed, close-coupled cantilever type. Canards enhance aircraft low speed handling, maneuvering and short field performance through the generation of high energy vortices The canards are of lifting type, adding to aircraft gross wing area. Leading edge canard sweep is 36° and trailing edge sweep is 19°. Canard dihedral is 3°. Canard unit span is 6 ft 0 in. Total canard area and aspect ratio is 36.37 sq ft and 4.03 respectively. Canard mean airfoil is a NACA 65-209 section.
Canard construction consists of two Ti-6222 spars, seven Titanium ribs and Titanium skins. Canards benefit from laser formed components which are laser welded to form a smooth, high tolerance finish. Canards incorporate flaperons of Aluminum construction which operate collectively with the all moving horizontal stabilizer to enhance pitch rate.
To improve low-speed handling and enhance pitch rate, turboprop Machetes may feature nose mounted all moving canard-vaders of graphite/polyimide construction. Of conservative sweepback, high aspect ratio and with pronounced anhedral, these small foreplanes work in conjunction with the horizontal stabilizer to improve pitch rates while serving as an active flight control surface to aid in the damping of turbulence/enhancement of gust response as coupled to the aircraft flight control system.
The Machete empennage consists of an all-moving, mass balanced horizontal stabilizer for longitudinal stability and pitch control and twin vertical stabilizers. The empennage is close-coupled to the aircraft wing to improve instantaneous maneuverability and reduce aircraft physical dimensions. The empennage is mated to Machete via the wing mounted integrated empennage support boom structure and aerodynamically contoured fuselage braces which blend directly into the horizontal stabilizer. Both the horizontal and vertical stabilizers are equipped with EESS deicing.
The Machete horizontal stabilizer has a leading edge sweep of 34° and trailing edge sweep of 10.3°. Horizontal tail unit span is 10 ft 3.5 in. Total horizontal tail area and aspect ratio is 88.52 sq ft and 2.39 respectively. Horizontal tail mean airfoil is a NACA 0009 section and anhedral is 8°. The horizontal stabilizer is composed of three Ti-6A1-4V Titanium sine-wave spars and ten IM9/polyimide ribs. Horizontal stabilizer skins are flush riveted IM9/polyimide. Maximum horizontal stabilizer deflection angle is +/- 40°.
The vertical stabilizer is composed of three Ti-6A1-4V Titanium sine-wave spars, five IM9/polyimide false spars, six titanium ribs and flush riveted IM9/polyimide skins. Each vertical stabilizer features a IM9/polyimide rudder. Rudders incorporate trim tabs and are capable of deflection angles of +/- 35°. Each vertical tail incorporates a Spectra®/PR tip antenna fairing for vertical tail mounted antennas, EW and RWR.
FUEL SYSTEM
The aircraft fuel system is of OBIGGS pressurized type, composed of five rigid self-sealing fuel tanks and one feeder tank. The OBIGGS employed is the Carlton NC1029.
Four of the fuel tanks are located within the fuselage, while the remaining two tanks are located within the port and starboard wing respectively. The maximum useful internal fuel load for the SM-27S/T is 5,000 lbs, equivalent to approximately 747 gallons of JP-8 (at 6.7 lbs/gal) or 770 gallons of JP-4 (at 6.5 lbs/gal). SM-27S/T fuel tanks are sized for 770 usable gallons of JP-4, resulting in a total capacity of 775 gallons, including the volume necessary to accommodate self-sealing cells. Unusable internal fuel equates to approximately 40 lbs.
A probe-and drogue in-flight refueling system may be installed within the fuselage nose section as a customer, cost plus option. The refueling probe for the in-flight refueling system is of retractable type based upon technologies developed by Sargent Fletcher in their ART/S Aerial Refueling Tank System. The retractable refueling probe system will likely be produced by Sargent Fletcher.
Machete Airframe Systems include flight controls, hydraulics and electrical units. The SM-27S/T flight control system is a full-authority, Digital Fly-By-Wire (FBW) flight control system.
Ailerons, flaperons, rudders and stabilators are internally mass balanced. Ailerons and rudders feature electric trim tabs controllable through a control column rheostat. Stabilators feature electric trim, actuators for which are located in the support boom. The SM-27S/T is fully aerobatic and will perform standard maneuvers including the stall, slip and spin, without departure., with stall, slip and spin modes being permitted by the FBW system to enable full exercises throughout the advanced training syllabus.
The Machete features two, independent, 4,000 psi hydraulic systems. Hydraulic functions include landing gear extension and retraction, trailing and leading edge flap extension and retraction, canopy extension and retraction, crew boarding ladder retraction, clamshell cowling actuation and ventral airbrake actuation. Hydraulic pressure is maintained automatically. The hydraulic power package supplies hydraulic pressure and incorporates an electrically-powered variable displacement motor/pump, a reservoir and low pressure filter. A nitrogen-charged accumulator is used to minimize pressure loss while allowing for thermal expansion. The aircraft hydraulic system employs Spectra® filament wrapped titanium lines and non-flammable hydraulic fluid for survivability.
The SM-27S/T electrical system supplies 115 volt, three-phase, 400 cycle AC power and 28 VDC per MIL-STD-704D. Three independent sources are used for power generation consisting of a primary starter/generator, a secondary generator and two batteries. AC power is supplied by two engine driven static invertors rated at 125 volt amps, providing outputs of 26 VAC at 400 Hz and 115 VAC at 400 Hz. Power is normally supplied by one invertor with the second serving as a backup. DC power is supplied through one 24 VDC, 40 amp-hour, nickel-cadmium battery. The starter /generator is a combination engine starter and 28 VDC, 300 amp generator. The secondary generator is a 28 VDC, 130 amp generator. An external 28 VDC power connector is provided within the engine bay.
The Machete features hydraulically actuated, retractable tricycle landing gear. The main landing gear consists of wing mounted, single-strut, oelo-pneumatic, single wheel units featuring carbon disk brakes. Main wheels use 24 x 8.0-13 size tires including Goodyear 18 ply rib tread with a maximum inflation pressure of 285 psi. The main gear retracts 90° inboard, with wheels stowed in the wing center section carry-through box upon retraction.
Nose landing gear retracts forward and is an oelo-pneumatic, fork-braced single wheeled unit. The nose wheel uses 19 x 6.75-8 size tires including 10 TL ply, Goodyear Rib tread with a maximum inflation pressure of 110 psi. Nose wheel steering, and main gear braking, is provided via rudder pedal inputs. Nose gear may be gravity extended in the event of hydraulic failure.
The landing gear is capable of unprepared, forward operations and sink rates of 15 ft/s enabling a high tolerance to hard landings. Maximum landing gear deployment airspeed is 200 Kts. Machete wheelbase is 14 ft 11 in. Machete wheel track is 10 ft 9 in. Nose gear/main gear weight distribution is 15/85 at MTOW.
Substantial emphasis has been placed upon ensuring SM-27S/T survivability in the low-level, hostile environment. In so doing, significant quantities of both integral and discrete armor are incorporated throughout the airframe.
Integral Armor consists of primary aircraft structural elements that not only serve as load-bearing members, but also provide an element of armor protection by inherent design. Featuring fail-safe construction throughout, the Machete wings and canards feature two sine-wave Titanium spars and numerous titanium sine-wave ribs. These spars and ribs in-turn assist in shielding discrete, self-sealing wing fuel tanks. Machete horizontal and vertical stabilizers feature three sine-wave spars and multiple sine-wave ribs. This use of Titanium spars and ribs significantly improves aircraft survivability. Employing significant quantities of geodetically arranged Titanium mated to Spectra® ballistic material, the Machete fuselage is of inherently survivable and crash-worthy design.
Presenting a compact, close coupled arrangement, the Machete configuration is directed toward survivability. The empennage, for instance, is configured such that the GRP skinned vertical stabilizers provide the aircraft propulsion system with a degree of profile shielding.
Machete Discrete Armor consists of materials which function wholly as armor, serving no secondary structural purpose. The SM-27S/T employs no less than 500 lbs of Discrete Armor, strategically placed within critical vulnerable areas including around/about the aircraft powerplant (engine cowling case armor), electrical generation, environmental, hydraulic and control systems, as well as around the internal ammunition drum. To ensure crew survivability, the Machete cockpit is an integral unit contained within a unitized Cockpit Armor Module (CAM). The CAM is a laser welded, armored structure, conceptually identical to the A-10 crew protection structure. The Discrete Armor used throughout the Machete, including the CAM, is a Stavatti proprietary laminate of alloy and composite materials including multiple layers of Spectra® 2000/Spectra®Shield. Thickness of the Discrete Armor laminate varies based upon specific application, ranging from 0.25 in to more than 1.25 in.
Ensuring crew survivability, the SM-27S/T is equipped with the highly reliable and proven Martin Baker MKUS.16L zero-zero ejection seat. The ejection seat is provided with both sequential and auto-eject features. Incorporating a comprehensive internal electronic countermeasures suite, proven Radar Warning Receivers, Laser Warning Receivers, Missile Approach Warning Systems and Self Protection Jammers produced by Elisra, Elta and/or Raytheon are carried as customer selected, standard equipment.
