April 28, 2008 Tilt-rotor aircraft have been around since the 1950s, offering the vertical take-off, hovering and landing abilities of a helicopter with the range, high flight ceiling, speed and fuel economy http://en.wikipedia.org/wiki/Fuel_efficiency of a turboprop aeroplane. Falx Air Vehicles are planning to push the fuel economy angle even further by using a hybrid-electric motor http://en.wikipedia.org/wiki/Electric_motor and inbuilt solar arrays. The company expects its upcoming compact single and double-seater tiltrotor aircraft to use as little as 10 litres of fuel per hour airborne, and the quiet electric operation should see these small, light and manoeverable aircraft make solid stealth vehicles for military uses. Though not yet confirmed, we may see a full-size prototype as early as the Farnsworth air show this year, and Falx is aiming to have the craft fully certified by the end of 2009.

Staffordshire, UK's Falx Air Vehicles yesterday released the final design overview of its hybrid-electric tilt-rotor aircraft platform, which it is looking to commercialize in the next 24 months. The platform can be configured as either a single seat personal vehicle or a two-seater for training or personal use. Using aerospace-certified composite materials, the single seater weighs in at only 350kg, with the twin-seat version weighing 405kg.

Falx claims the battery packs powering the Falx will be the latest fast-charge battery systems the USA has to offer, but no further details are available. The batteries will be charged both by inbuilt solar relays and through the use of a small 100hp combustion engine that drives a lightweight, brush-less generator. Noise and thermal image will thus be kept to a minimum, enhancing the craft's stealth abilities. The twin electric engines eliminate a lot of complex machinery in traditional tilt-wing craft, such as drive-shafts, hydraulics http://en.wikipedia.org/wiki/Hydraulics and gearboxes.

Its VTOL abilities will make the Falx platform able to access landing areas without the need for a runway; the tilting rotors simply face upward in takeoff, landing and hovering situations, and the craft acts like a twin-rotor helicopter. The electric motors develop around 240 horsepower http://en.wikipedia.org/wiki/Horsepower at peak output in VTOL applications. Once airborne, the rotors slowly tilt forward, moving the craft's thrust to a horizontal plane and developing enough velocity http://en.wikipedia.org/wiki/Velocity for the wing to provide lift.

No information is yet available on the range, speed or flight ceiling of the Falx tilt-rotor craft, but tilt-rotors are well known for offering airspeed, range and flight ceilings much higher than comparable helicopters.

Falx is seeking investment in order to commercialize the platform, which it hopes to be fully certified and ready for the market by 2010. The company expects interest around police, military and paramedic http://en.wikipedia.org/wiki/Paramedic circles but the platform also offers clear advantages to leisure aviators http://en.wikipedia.org/wiki/Aviator - a lot of large yacht owners will see the benefit of a long-range, highly fuel efficient aircraft that can operate off a helipad. In all, more than 52 variations of the design have been envisioned for support services and commercial applications.

About Ka-50:

Any information about this helicopter was strictly secret in 70's and 80's. American intelligence services had problems to get any information about its development. The situation has rapidly changed a few years ago. Everybody could see the brand new Kamov helicopter on Paris Airshow 92' for the first time.

Helicopters from the Kamov Company have traditionally been given NATO codenames beginning with the letter "H", and the Ka-50 Black Shark helicopter carries the NATO codename Hokum A, Hokum B being the two-seat version, Ka-52. Ka-50 is also known as Werewolf. The Ka-50 Black Shark entered service in the Russian Army during 1995 and is in full production at the Sazykin Aviation Company Progress based in Arseniev maritime Territory, Russia. It is a high performance combat helicopter with day and night capability, high survivability and fire power to defeat air targets and heavily armoured tanks armed with air defence weapons.
Development:

The development of this helicopter had started in year 1978 according to specifications annonced by Soviet Ministry of Defense in 1977. Codename V-80 was used till 1992, when the name Ka-50 was given to new Kamov helicopter. Kamov Ka-50 was designed for usage over the land, not for naval operations as almost all Kamov helicopters before (e.g. Ka-25 or Ka-27). The first model 1:1 was showed to Soviet Military Chiefs in May 1980. In two years on 17 June 1982 the first flight was accomplished. Kamov Ka-50 had serious competitor. Mil worked at the same time on brand new Mil Mi-28 (known as Havoc now). Both aimed to win the tender for new helicopter. When testing Ka-50 and Mi-28 helicopters, Ka-50 seemed to be better. Mil wished tests of helicopters repeated. Three times both types were tested, but Ka-50 was better in every test. Soviet Ministry of Defense decided to continue development of both competitors.

The development of the Ka-50 Black Shark and AH-64A Apache combat helicopters aimed to redress this disparity and make the helicopters able to defeat tanks armed with air defense weapons. The Ka-50 combat helicopter can be used to defeat targets on the battlefield within wide ranges of launching high-precision supersonic antitank missile systems, including launches from more than a 6-km range within a stand-off zone of air defense artillery and air defense missile systems. The Ka-50 combat helicopter is intended to defeat modern armored and mechanized materiel, air targets and hostile manpower. This co-axial helicopter features a high flight performance and ease of piloting via automated flight devices. It can successfully execute combat missions day/night owing to high survivability under hostile fire, powerful armament and comfortable pilot's cockpit. The helicopter was tested in simulated combat conditions. . The Ka-50 helicopter is unrivalled in the world in terms of the 'cost-efficiency' criteria. In 1995 the Ka-50 combat helicopter entered service and is now series produced at Progress Arsenyevsk-based aviation complex.

Helicopter Dynamics Modeling:

Forces and moments

Rigid body dynamics equations have been used to calculate the helicopter’s flight trajectory. In essence, this means that all external forces and force momentums are used to calculate a body’s position and rotation in 3-D space.

The Ka-50 airframe aerodynamic properties are derived from its sub-element parameters: fuselage, wings, tail, and landing gear. Each of these has its own position and orientation within the airframe local-coordinate system and each has their own aerodynamic characteristics. Each sub-element is calculated by independent lift-drag coefficients diagrams, damage degree influencing the lift properties, and center of gravity (CG) position and inertial characteristics. Aerodynamic forces acting on each sub-element of the airframe are calculated separately in their own coordinate system taking into account local airspeed of the sub-element.

Contacts with the ground and external objects are modeled based on rigid contact points system.

Powerplant

Show description
Engines and power train
The Ka-50 powerplant consists of a gearbox with free-wheel clutches, two TV3-117VMA turbo-shaft engines with electronic engine governors, an auxiliary power unit and turbo-gear.

For the first time in flight simulation history, the engine model is based on detailed physics model of turbo-shaft engine as a system of separate components of the engine gas-dynamics system: engine inlet, compressor, combustion chamber, high-pressure turbine and power-turbine with engine exhaust.

The model corresponds to the real engine in all modes of operation in terms of output power, acceleration, compressor RPM, exhaust gas temperature (EGT) and fuel consumption, in relation to the ambient air temperature and pressure. Operation of bleed air valves is modeled for the compressor anti-stall system, engine’s deicing system and the dust cyclone. By reducing the airflow through the engine, these devices increase the EGT and lower the take-off power of the engine. Engine components parameters degradation is implemented in the model within the service life or in case of exceeded operation limitations of take-off and emergency power modes or power loss with EGT over-limit.

Show description
TV3-117 engine
Compressor choking caused by intake icing is modeled so that it leads to power loss, EGT increase, compressor stall and engine flame-out. Flame-out is modeled using air-fuel ratio calculation in the combustion chamber. The engine control system, as in real life, consists of turbo-compressor (gas-generator- GG) RPM governor, power-turbine RPM governor, automatic engine start-up and acceleration devices, electronic engine governor (EEG) that limits the max EGT and monitors/limits the power-turbine RPM. Except for direct engine control, the control system incorporates start-up cycle of the APU, main engines and turbo-gear, engine and engine controls test equipment like engine false start, engine vent (crank), EEG test, rotor (power-turbine) RPM governor readjustment and many more.

Cockpit Instruments

The Ka-50 cockpit instruments are generally traditional electro-mechanical gauges that are mounted on the front dash and side / back panels. These instruments are divided into three general groups: flight control, engine control/monitoring and systems control. Other cockpit interfaces include traditional switches, dials and multiple-position switches. Additionally, the Ka-50 has multiple banks of warnings lights and cockpit illumination controls.