Reimagining The Stalma

Today Stavatti officially launched the program to reimagine the SM-36 Stalma as a sixth generation Multi-Role Fighter with a scheduled industry release of the new design before Christmas 2017.

The Multi-Role Fighter is the back-bone of modern air defense. Proficiently satisfying air-to-air and air-to-surface engagements with unprecedented flexibility, the Multi-Role Fighter (MRF) is the leading combat asset of western air forces. The MRF has become the most procured of all fighter types, with over 7,000 MRFs now in service worldwide. Performing critical missions with stunning success, MRFs including the F-4 Phantom II, F-16 Fighting Falcon, and the F/A-18 Hornet and Super Hornet are legendary.

The SM-36 Stalma will continue the legend. Reimagined as a sixth generation MRF developed to succeed both F-16s and F/A-18s while exceeding CTOL F/A-35A/B JSF performance in all regimes, the SM-36 Stalma will be an alluring super-fighter for the 21st century. A synergistic integration of aerodynamics, distinct configuration and the most advanced software driven avionics, sensors and electronic warfare systems, the SM-36 will be a lethal instrument like no other.

The SM-36 is a single engine, single seat (SM-36S) or two seat tandem (SM-36T) MRF. An all-weather platform primary mission capabilities include Air Superiority (AS), Combat Air Patrol (CAP); Deep Penetration Precision Strike (DPPS) utilizing conventional or nuclear devices; and Close Air Support (CAS). The SM-36 design results in a high performance aircraft with great acceleration, climb and instantaneous turn rates with exceptional maneuverability to fulfill both close-combat/dogfight and air defense roles. Secondary emphasis has focused upon Low Observable (LO) features and supercruise.

The need for a suitable successor to F-16s and F/A-18s was a driving force behind the 1994 founding of Stavatti Corporation and the launching of the SM-36 project. From 1994 to 2000, Stavatti’s business focus concentrated on the design and engineering of the SM-36 as a private sector developed aircraft to replace F-16s and F/A-18s worldwide. As it was evident that the F/A-35 JSF was the F-16 and F/A-18 successor of choice for US/NATO air forces, development of the SM-36 was suspended in 2000 to focus upon next generation attack and light-weight fighter aircraft.

By 2016, the global need for an affordable, capable multi-role fighter to replace F-16s and F/A-18s again became apparent with the rising costs and capability shortfalls of the F/A-35. In late 2016 Stavatti started re-thinking the SM-36 and began working on a complete update and redesign of the aircraft. While the Stalma retains its general feel, a completely new aircraft is now being engineered to serve as fighter for 2025.

The SM-36 is now in a state of complete re-design. While a baseline configuration for the new aircraft has been established, the new configuration will not be frozen until late-2017. Significantly improving upon the original design, the new SM-36 will be a larger aircraft, comparable in size to an F/A-18E, but with the unswept wingspan of an F-14. A single-seat multi-role fighter, the new SM-36 will retain the variable-geometry swing wings that provide 5 degrees of wing sweep for landing and more than 70 degrees sweepback for supersonic cruise.

While the SM-36 could be built today, being powered by a 43,000 lb class F135 engine, Stavatti’s current plan is to work with engine manufacturers, to integrate an Advanced Cycle powerplant that is optimized for supercruise and delivers up to 52,000 lbs augmented thrust/40,000 lbs dry thrust. This engine will also be used to power the SM-39 Razor. Postponing SM-36 introduction until the 2025 time-frame will allow that maturation of engine and avionics technologies allowing the SM-36 to be an extremely capable aircraft when it enters the market.

The new SM-36 will be produced in piloted and autonomous variants. Manned versions of the SM-36 will likely feature Martin Baker MK16E zero/zero ejection seats. A single engine fighter, the aircraft enhanced performance engine will be equipped with a lo-observable thrust vectoring nozzle. Powerplant airflow will be supplied by a single variable geometry, internal compression ventral air intake. This ventral intake will provide steady, stable airflow at high AoA while allowing high pressure recovery during supersonic flight in excess of Mach 2.6 thanks to its variable geometry.

With high aspect ratio variable geometry swing wings featuring double slotted Fowler Flaps, leading edge slats and spoilers, the SM-36 will offer extraordinary low speed handling, maneuverability as well as smooth high speed operation. Balancing the wing, all moving forward swept canards and a V-tail equipped with slab rudder-vaders will provide pitch authority and directional control.

An electric aircraft, the SM-36 will have a quadruple-plex, digital Power-By-Wire flight control system with electromechanical actuators. Reducing overall systems weight, the SM-36 will not require a centralized hydraulic system.

Equipped with tricycle landing gear, the SM-36 will be designed for a 20 ft/sec sink rate as well as carrier catapult launch via towbar. The SM-36 main gear are of trailing-link design featuring a single wheel. The SM-36 nose-gear is a two-wheel, forward retracting unit. The aircraft will be built for both land and USN carrier based flight operations.

Structurally, the SM-36 will have a titanium foam metal sandwich structure consisting of titanium foam metal or aluminum foam metal cores sandwiched between titanium skins. Nearly an all-metal aircraft, the titanium foam metal sandwich offers a near-monocoque, high temperature, corrosion resistant structure. This structural approach will be pioneered in the Machete program with the SM-47 being the first supersonic aircraft to benefit from a foam metal sandwich airframe. Service life is projected at 16,000 hours.

The SM-36 will feature an advanced avionics system, integrated via a proprietary computational network of secure black-boxes operating within the context of a MIL-STD-1553B Interface Bus. A modular platform, the aircraft was developed to incorporate a variety of avionics as Line Removable Units (LRUs). Actual SM-36 avionics selection will not begin until 2020, however it will feature AESA radar, an integrated sensor/EW suite, software driven dynamic avionics, an all glass cockpit with large area active displays, a Canopy Embedded Display (CED), and a comprehensive EW/ECM self protection suite that matches or exceeds the capabilities of the F/A-18E/F and F/A-35A/C.

The SM-36 will employ technologies to significantly reduce Radar Cross Section (RCS), infrared signature, electromagnetic signature, visual signature and aural signature. To reduce RCS, the aircraft will employ a geometrically based radar disbursing configuration. All-aspect RCS reduction may be achieved through the application of Stavatti proprietary Active Wave Attenuation Stealth Technology. In the new, all titanium foam metal sandwich aircraft, Stavatti has elected to apply the Active Wave Attenuation RCS reduction system as employed in the SM-39 to result in an RCS value on the order of 0.006 square meters. This approach will allow the swing wing SM-36 to achieve a low, all-aspect RCS.

Reduction of IR emissions is achieved through the use of a dedicated engine bay cooling/IR signature reduction system. For enhanced aural signature reduction, Stavatti is considering Active Frequency Damping (AFD) and comparable active noise control systems. Visual signature is reduced through employment of smokeless turbofans (ACE), limiting overall aircraft size and active camouflage technologies under development by industry partners.

SM-36 fixed internal armament includes a single 20mm M61A2 Vulcan cannon. Located in the port mid-fuselage, the cannon will be equipped with a retractable muzzle cover. The SM-36 will carry 1,000 rounds of ammunition. Alternatively, the SM-36 may feature an engine driven Gas Dynamic Laser (GDL) directed energy weapon as its primary fixed internal weapon. This GDL would employ a Stavatti proprietary laser weapon system currently at a TRL of 4. Stavatti anticipates the GDL to rise to a GDL of 7 by 2020 and be at a TRL of 8 by the first flight of the SM-39 prototype. Stavatti is developing this weapon system to serve as a standard air-to-air offensive system (and defensive anti-missile) for aircraft including the SM-39 and SM-36.

Expendable internal ordnance is carried in two internal weapons bays mounted vertically within each of the aircraft port/starboard weapons bays. Each internal weapons bay will be rated to a 3,000 lb stores carriage capacity and is suitable for carriage of a variety of air-to-air missiles and guided munitions including AIM-120s, AIM-9s, AGM-65s, GBU-31/32/38/39 and B61s. The SM-36 will also carry up to 20,000 lbs of stores externally on six wing swivel hardpoints. Of the six hardpoints, four will align themselves with the freestream when the wing is fully swept while two must be jettisoned prior to wing sweep.

The reimagined Stalma is being jointly developed by Stavatti Aerospace Ltd in California and Stavatti Europe in Serbia as a Internal Research and Development (IR&D) effort. The aircraft will be marketed by Stavatti as a potential MRF solution for the USAF, USN and a variety of allied air forces worldwide.