By Garth Calitz

The Titanium Explorer is the first of a new generation of gyros to be produced in Australia and is the world's first to utilize titanium. This concept was conceived by two friends, Neil Sheather and Andrew Pepper, in 2009 after they observed that existing gyro models could be improved with design enhancements to make them more practical for exploring one's own country. Additionally, Neil, having balanced various rotor systems on different gyros, resolved to design a rotor and rotor head that would operate smoothly and without shaking.

The explorer features a comprehensive dashboard equipped with a mini iPad to download essential information needed by the pilot. Standard instruments include an airspeed indicator, vertical speed indicator, altimeter, rotor trim/brake pressure gauge, rotor tachometer, engine tachometer, cylinder head temperature gauge, oil temperature gauge, oil pressure gauge, fuel level indicator, and an hour meter. An XCOM radio and Microair G transponder can be added if needed. Additionally, a rear instrument panel for training purposes can be optionally installed, replacing the key-lockable glove box.

The 180-litre storage pods offer ample space, eliminating the need to store items and equipment around your feet, which could cause issues during flight. These pods are designed to accommodate long items like folding chairs, tent poles, and even fishing rods, making them ideal for exploration.

The explorer is equipped with either the Rotax 912 engine, which delivers 100hp, or the 914 turbo engine, offering 115hp. The Rotax engine series was selected for its demonstrated reliability across different conditions.

The primary structure is constructed from titanium, offering double the strength of stainless steel or chromoly and twice the elasticity of stainless steel, making it ideal for gyros as it absorbs rotor pulses, resulting in a much smoother flight. Titanium has long been utilized in the aviation industry due to its exceptional strength and capacity to endure both heat and stress. Additionally, its lightweight nature makes it an excellent choice for gyros.

The body consists of carbon fiber, fiberglass, and honeycomb, providing exceptional strength and enhanced safety for both the pilot and passenger. The rotor is crafted from a full composite blade, ensuring durability and the necessary strength.

The rear suspension is constructed from 7000 series aluminum, performing excellently on rough runways, and is complemented by the rubber block suspension at the front. The tight turning circle allows for easy U-turns at the end of the runway, eliminating the need for a three-point turn.

All pedals, controls, wheels, rotor head, and any other components that can be made from titanium have been crafted this way to enhance strength and reduce weight. This remarkable machine has a dry weight of just 270kg. The welds, expertly handcrafted, are truly artistic, with all frame welds undergoing heat treatment after welding. The heat treatment process takes 5 to 6 days to complete; it requires 2 days to heat the oven to approximately 500 degrees, maintaining that temperature for 2 days before cooling down, all within a vacuum and oxygen-free environment. The frame is constructed in three sections and assembled using 5mm Gr 5 Titanium plates and crush tubes, eliminating the risk of cracking around the mast.

All TAG explorers are equipped with dual controls, featuring a rear stick that includes all the same controls as the front stick, such as a rear brake lever and pre-rotation controls. The large front windshield shields the pilot from wind exposure, and after extensive testing in 3D wind tunnels, a solution was devised to reduce the airflow into the rear seat, enhancing the passenger's comfort. The front cockpit's entry door provides easy access to the spacious and comfortable seat.

The fuselage and tail are constructed from carbon fiber and honeycomb materials, vacuum-formed into the mold, resulting in a structure that is both very strong and lightweight.

TAG prioritizes safety above all else. When designing the 83-liter fuel tank, they sought the best material available. After extensive research, they chose High-Density Cross-Linked Polyethylene (XLPE), a thermoset resin tailored for critical uses such as chemical storage and fuel tanks. In the XLPE manufacturing process, a catalyst (peroxide) is incorporated into the resin, creating a free radical. This free radical initiates the cross-linking of the polymer chain, effectively turning the tank into a single large molecule. The resulting resin is specifically engineered for essential chemical and fuel applications. XLPE offers twenty times the environmental stress crack resistance, ten times the molecular weight, and five times the impact and tensile strength of standard HDPE.

Over the past 30 years, most helicopter companies have reverted to producing fully composite rotor blades and hubs. The primary reason for this shift is the fatigue issues associated with rotor blades made from aluminum. Recently, there have been reports of aluminum rotor blades developing cracks in gyro copters. Composite rotor blades typically have a longer lifespan, do not suffer from fatigue (as long as they remain undamaged), and provide a smoother flight experience. This is because, when designed correctly, composite rotor blades can flex during flight, absorbing significant loads and reducing teetering on the hub bar.

TAG has created the strongest and safest rotor blades ever designed for gyro copters, collaborating with some of the world's leading aerospace composite engineers. With their extensive expertise in helicopter rotor blades, we developed a rotor spar that is as robust as those used in helicopters.

The composite rotor blades we created for the Titanium Explorer are constructed from pre-preg carbon fiber. "Prepreg" refers to a reinforcing fabric that has been pre-impregnated with a resin system. This resin system, usually epoxy, already contains the appropriate curing agent. Therefore, the prepreg is ready to be placed into the mold without needing additional resin. To cure the laminate, a combination of pressure and heat is required. The TG (the temperature at which the resin begins to soften) for prepreg carbon fiber is approximately 120 degrees Celsius, compared to wet-laid composites, which have a TG between 65 to 85 degrees. This advancement allows for the first-time creation of pure black composite rotor blades.

The advanced open pre-rotor system is designed to allow the pilot to control the rotor spin-up speed, reducing system overstress and addressing issues of air valve blockages from dust and moisture. It operates very quietly and is highly efficient. A manual pre-rotor lever has been added as a backup in case the primary system fails, and it also helps align the rotor forward and aft on the ground.

The pre-rotor system on the Titanium Explorer can spin the rotors up to over 300 RPM. While this is not recommended for regular use, it is extremely beneficial for very short field take-offs. An early warning system for low-speed rotor flap has also been developed, significantly reducing accidents caused by inattentive pilots.

Overall, the TAG Explorer appears to effectively meet all the needs and concerns of the South African Gyro community.

#TAG #Explorer #Gyrocopter