Two-Part Mast System (Patented)

Many of the gyroplane designers copied the early basic design of the 2×2″ mast. Or opt for a rigid mast configuration. The mast had the engine mounted at some point between gimble head and keel.

The thrust line became a pivot like a teeter-totter.  Provided that the dynamic weight of the rotor was equal to the weight of the pilot and fuel, then the aircraft flew quite nicely.

However, the rotors are always changing in lift and drag. As the drag increased, the mast would bend back. As the air equalized in the rotor disc, the drag was reduced.  This allowed the mast to spring back to its normal spot. This causes all kinds of control issues for pilots. RAF discarded this 2×2″ tube and replaced it with the more robust and rigid 2×4″ mast.

The 2×4″ mast, (the engine pylon) is about 48″ long, and extends about 6″ over the pilot’s head. The upper part of this 2×4″ tube is stuffed with a dressed piece of hardwood. Two holes are drilled through the tube and wood, spaced about 8″ apart. A rubber bushing is inserted through the top hole and a center of gravity adjuster in the bottom hole.  Two cheek plates (2×4″ x 3/16″ x 36″) are attached to the sides of the mast with two AN36 bolts extending through one plate, the rubber bushing in the mast, and out through the other plate. The second bolt goes through one plate into the patented C of G adjuster and out through the second plate.

The gimble head is then attached to these cheek plates. The rotor mast (cheek plates) could now flex back and forth and side-to-side independently as the rotor blades moved in flight.

Push Tube Configuration (Patented)

Unlike the “other” gyroplanes on the market today, the push tubes on the RAF 2000 gyroplane are out in front of the gimble head at an opposing angle to the mast. Why put the push tubes at an opposing angle to the mast? This is done to stop resonant vibration in the control push tubes.

The push tubes are put into tension when the pilot makes a control input to descend, thus the push tubes cannot bend slightly, and resonant vibrations do not like to travel down an opposing angle.

When the RAF pilot makes a control input to descend or to correct a slight pitch up, only one thing happens, the gyroplane descends in a controllable attitude.   The push tubes do not spring straight – the thrust line does not change. It is a controllable descent, even in a high-speed environment.

On the RAF gyroplane, the push tubes are at an opposing angle (out the front of the head), thus when a wind gust or unstable air hits the rotor disc the cheek plates flex back slightly causing the push tubes to hold down on the front of the torque tube this prevents large changes in the rotor blades angle of attack to the forward motion.   The same holds true for a descent. This action reduces the movement of the rotor lift vector in relation to the C of G of the aircraft, the RAF 2000 has an adjustable C of G.

The RAF 2000 Gyroplane push tubes are also SPLIT at the midpoint. This split push tube control system was incorporated so that any vibration would stop at the midpoint and not affect the lower control yoke going into the joystick.

The split push tube design also allows the owner to be able to fold down the mast for transportation or storage.

Rotor Stabilator (Patented)

RAF introduced this innovation at Air Venture Oshkosh, Wisconsin in 2003.

In comparison to fixed-wing aircraft, rotor rotation and size provides improved controllability at low airspeeds.  In fact, current gyroplanes display greater agility than airplanes throughout the airspeed range.

Advantaged by the rotary-wing, gyroplane control responsiveness, variates less versus airspeed than with fixed wing airplanes.  However, control inputs still gain sensitivity as forward airspeed increases.  Some pilots find piloting tiresome if turbulent air jostles the rotor disc at higher flight speeds.  Novice and non- proficient pilots may be prone to over-control in these same conditions.

The two rotational axes between fuselage and rotor disc removes the ingrained visual reference between wing and horizon for fixed –wing conversion pilots.  Rotor motion independent from fuselage motion creates control system movements that further complicate conversion from the fixed-wing practice.

That is why the innovation was introduced by Rotary Airforce and each production-built RAF2000 gyroplane is equipped with a Rotor Stabilator and not a Horizontal Stabilator, the RAF 2000 gyroplane is different in many ways from other types.

In a gyroplane the rotor-disc is flown, not the fuselage, by controlling the rotors which are always changing in lift and drag, the Rotor Stabilator acts to control the rotors in flight and gives the pilot feedback when making maneuvers.

The Rotor Stabilator is a system that controls the rotor disc yet leaves the pilot with full control of the aircraft.  The Rotor Stabilator gives a full electric trim in pitch and roll even in more turbulent air.  The Rotor Stabilator has proven to be an effective way to control pitch inputs by the pilot or external forces.

The Rotor Stabilator trims rotor motion in steady level, climb, and descent flight.  Air passing over the Stabilator counteracts minor rotor pitch movements and keeps the aircraft flying straight and smooth.  Maintaining a fixed flight attitude by applying airflow against a control surface is called dynamic trim.

The dynamic trim provided by the Rotor Stabilator adjusts through all flight speeds and increases in effectiveness as the airspeed increases.

The Rotor Stabilator is the only dynamic trim device available for gyroplanes that dampens rotor motion.  Rotor orientation primarily determines gyroplane motion.  Common sense dictates that dampening rotor motion will most effectively dampen gyroplane motion.

Benefits

Reduces pilot workload, increases control stick feedback, improves trim as airspeed increases, dampens rotor motion, enhances the flying experience

Rotor Blades by Design

The RAF rotor blades have an aluminium Spar that is 1.38 sq. inch of 6061 T6.  6061 T6 Aluminium has a shear and tensile strength of 45,000 lbs. /sq. Inch.   The RAF 2000 Rotor blades use a D-Spar that is 1.38 X 45,000 = 62,100 lbs. in shear and tensile. 

During flight the RAF 2000 Rotor blades will experience a loading of 12000 pounds in centrifugal force, 31 tons in shear for our blades.

The RAF Rotorblades have a foam core and RAF makes use of leading airfoil technology and composites.
the Rotor blades have a built-in 3-degree twist that gives you more lift across a greater portion of the blade.
The blades further have a tip weight and have greater kinetic energy which gives you more stability in the air and better landing capabilities.

Composite construction on an aluminium spar provides a completely sealed unit, thus eliminating any corrosion problems.