The patented design of the TWIN-X6 aircraft is unique in many ways:

• Optional Amphibious Design: Patented design allows for the addition of a hull under the fuselage to switch from a convention land-only airplane to its amphibious variant;
• The largest cabin: Up to 72 inches wide and 55 inches high; a never-seen-before cabin space for a six-seater aircraft;
• Safety: Two engines but one is enough, lots of fuel and dual redundancy on critical systems to make sure it gets you there and brings you back safely;
• The Mistral engines: No vibration "turbine-feel" power control, reliable and not capricious, with a long life span and plenty of power in the case of an engine failure.
• Business Jet Comfort: Noiseless cabin with large reclining armchairs and an unprecedented panoramic view and skylights;
• The doors: Large easy unobstructed access directly at ground level;
• The opened nose deck: For fishing (or other activities), ease of access when beached or docked, and access for large luggage loading;
• The position of its engines: Total control in the case of an engine failure, unobstructed vision by propeller and absence of noise;

It was a strategic decision to keep the TWIN-X6 project a secret for as long as possible. The MAD Aerospace Corp. has been working on the design since 2011, using only private funding, to enter the market with a technically well-thought-out, patented aircraft design.

The name "TWIN-X" was originally selected because of the double "X" formed by the 4 blade propellers. With time, the name stuck and it was decided to keep it. The "6" refers to the 6-seater version of our design. At the start, three other models of our concept were made : a 2+2 seat version, a 4 seat version and a 4+2 seat version.

At the start, three other models of our concept were made : a 2+2 seats version, a 4 seat version and a 4+2 seat version. The 6-seater was the largest of our designs. Market analysis has shown that private owners prefer 4 or 6 seats. Moreover, a larger aircraft platform opens many doors for other markets such as business aircraft, cargo transportation, aero-taxi, medivac and search & rescue.

The estimated true airspeeds are:

• Economy cruise speed (@8000ft, 55% power): Over 150 knots (278 km/h)
• Cruise speed (@8000ft, 75% power): Over 170 knots (315 km/h)
• Maximum speed (@sea-level, 100% power): Over 190 knots (352 km/h)

With 600 pounds of payload on board, the TWIN-X6 has enough fuel for a 1200 nautical miles trip (1381 mi, 2222 km) on its main fuel tanks, and it can reach over 1500 nautical miles (1726 mi, 2778 km) with the optional long range tanks. With 1000 pounds, the range is 1050 nautical miles (1208 mi, 1944 km). Of course, the range always varies with the atmospheric conditions, the payload and the flight altitude.

The TWIN-X6 is designed to carry 2000 pounds of useful load, including fuel. With 6 people on board and 300 pounds of luggage, there is enough fuel to fly for more than 3.75 hours plus 30 minutes reserve; enough for an 850 nautical mile trip (978 mi, 1574 km).

The cargo compartment, located in the tail, has an internal volume of 28 cu.ft. and is designed to carry 300 pounds of luggage. The nose section of the aircraft can accomodate an additional 100 pounds of luggage in a 7 ft.cu. pressurized space and an additional 8 cu.ft. is available under the rear row of seats. Finally, the rear row of seats can be reclined inside the floor, allowing to trade seats for an additional 75 cu.ft. of cargo space.

Yes. The rear cargo compartment can be fully loaded when the aircraft is empty without any risk of seeing your beautiful bird falling on its tail.

No. This is a primary design criterion for us. With its propellers located behind the passenger compartment and the engine's exhausts directed outboard and upward, the cabin of the TWIN-X6 will be as silent as a luxury car.

Yes. The TWIN-X6 tricycle landing gear will be robust and highly capable. Oleopneumatic shock absorbers with trailing links are installed on all gears, large tires were selected and the legs' structure is triangulated to maximize its strength.

The hull of the TWIN-X6 is being designed to sustain the impact loads of 24 inches waves, which corresponds to Level 2.5 on the Beaufort scale. However, most seaplane pilots we've interviewed agreed that this is not something you would wish to do, and to be realistic about small seaplanes performances, you will be safer avoiding this limit.

Yes. The amphibious version of the TWIN-X6 is equipped with a retractable water rudder and a retractable water motor is available as an option. The reversible pitch propellers and the hydrodynamic V-hull ensure good characteristics during all manoeuvres on water. Finally, the float-wing design makes it impossible to capsize and renders the TWIN-X6 unsusceptible to high waves when performing a 360 degree turn.

Yes. The HVAC system is being designed to supply all the heat or cooling required to keep the cabin as comfortable as your living room in all weather conditions. The temperature control is automatic and can be activated remotely with your cell phone to ensure a comfortable environment when you arrive at your aircraft.

The TWIN-X6 will be filled with options; a true customizable aircraft where you can choose what you want according to your needs and tastes. Amongst many features, you can choose between an amphibian or a land-only plane, 2 choices of engines, pressurization, de-icing, exterior and interior colors, 34'' wide-screen TV with sound system and video games, onboard Internet, heated seats and yoke, electrochromic skylights, custom seats, refrigerated compartment for drinks and 2 tables that can be reclined into the side ledges.

At MAD Aerospace, we are proud to say that the TWIN-X6 is one of the safest twins ever designed in this category of aircraft. We aim to produce an airplane that thinks for the pilots and helps them do their job with minimal distraction.

• The configuration: By its unique design, the pilot keeps total control in the case of an engine failure;
• 2 powerful reliable engines: Should you lose one, you still have one, and it is strong enough to ensure safe flight with good climbing characteristics;
• Dual redundancy on systems: Engine control units, electrical systems, DC power generation, batteries, fuel system, pitot-static system and brakes have dual redundancy;
• Artificial stability: An electronic stabilization system automatically compensates for gusts and keeps the aircraft level;
• Stick shaker and pusher: If the aircraft gets too close to a stall, the yoke will shake, then an actuator will force the aircraft's nose down to prevent stalling;
• Instrumentation: Ergonomic full glass cockpit, FADEC engine control, satellite weather, angle of attack indicator, TCAS, SVT/ GPWS, autopilot and flight director;
• The hull: Makes available numerous water landing sites in case of emergency, and acts as a shield in the case of a belly landing;
• Unobstructed view: A good field of vision is always better for the pilots;
• Landing gears: Short and robust triangulated construction, large wheels, oleopneumatic shock absorbers on trailing links, wide track and long wheelbase for excellent ground stability and control;

Yes. The TWIN-X6 will be certified under the new Part 23 regulations, normal category, level 2, low speed.

By design, the TWIN-X6 has its engines placed close to the centerline of the aircraft, which greatly reduces the destabilizing effect of an engine failure. Besides, the propellers blow into the tail's control surfaces, giving the pilot full control authority of aircraft, even at low speed.

Should an engine failure occur, the TWIN-X6 will have a small tendency to yaw and bank toward the side of the inoperative engine, but that phenomenon will be much less aggressive than what it would be on a conventional Twin with wing-mounted engines. The pilot will be able to simply trim the yaw and roll controls to restore normal flight attitude. The remaining engine will have more than enough power to ensure safe flight with a good climbing capacity.

In final approach, there is no minimum control speed (Vmc) to respect, and the landing proceeds according to the normal procedures.

The TWIN-X6 control system is designed to make it a fun and safe plane to fly. We aim to give a "sporty" feel to the pilot, but the design itself is naturally stable and self-aligning. The ailerons, elevator and rudder movements are all electrically assisted to limit the loads on the yoke and ensure a proper proportional force feedback to the pilot to give a good "feel" of the bird's attitude.

Also, the wings are aerodynamically designed to ensure very smooth and predictable stalls at a high angle of attack, with easy stall recovery, to make it as forgiving as possible.

Any aircraft can stall; some are spin resistant, but the safest is to avoid both. That is why the TWIN-X6 is equipped with a SPS, for "Stall Prevention System". This system is standard on larger passenger aircrafts but we believe it should be standard in every aircraft.

The SPS operates in 2 steps. First, when reaching a high angle of attack, the yoke starts shaking to warn the pilot of a potential stall. Second, if the pilot does not react and keeps increasing the angle of attack, an actuator engages and forces the elevator downward for a moment, pushing the aircraft's nose down. This actuator is called a "stick pusher".

No. The float-wing design makes it impossible to capsize on water and renders the TWIN-X6 unsusceptible to high waves when performing a 360 degree turn.

No. The automatic stabilization system will not let you do it even if you try. Besides, on low-wing designs with dihedral, an air cushion forms under the wing when it approaches the ground, giving the aircraft a stable self-centering behaviour.

Yes. The overall field of vision will be unprecedented. The long nose of the TWIN-X6 tricks the eyes into believing that it will impair the pilot's vision, but that is not the case at all. A full size mock-up was used to test the pilot's vision, demonstrating that with the long canopy extending so far forward, excellent downward visibility is achieved.

The ballistic parachute is still being considered as these lines are being written. Should we choose to include it in the design, it would be offered as an option. Its location, with the required volume and structure, is already planned in the design but there are still other feasibility matters that need to be addressed before we commit to offering it. It is the company's opinion that the safest solution in case of an emergency is always to keep flying.

No. The TWIN-X6 touches down at standard speeds between 62 and 65 knots. It has an automatic stabilization system that assists the pilots in maintaining the aircraft's attitude, compensating for gusts.

The landing gear design, with a large track and wheelbase, makes it very stable on the ground. The nose landing gear is a bit shorter than usual so that when the 3 wheels touch the ground, the angle of attack becomes negative and the wing lift is lowered to "sit" the aircraft solidly on its wheels. The immediate weight-on-wheels increases the braking capacity and nose wheel steering authority.

Yes. The TWIN-X6 is designed to "sit" firmly on its wheels. The wheels are very wide spread and the center of gravity is low. In addition, the low-wing design with short tail makes it less susceptible to crosswinds. The main gears are located far enough behind the center of gravity to allow loading the empty aircraft with 300 pounds of luggage in the tail compartment without risking the plane falling on its tail.

Yes. The skin of the TWIN-X6 is almost completely covered with a lightweight aluminum mesh embedded within the outer laminate ply. Additional protection is provided in zones where lightning is most likely to attach. This provides a continuous conductive path of low resistance around the entire aircraft exterior that quickly conducts away the energy.

Yes. The TWIN-X6 will be offered with an optional de-icing system for the propellers and leading edges. Heated pitot tubes and static ports are standard, and heated fuel vents and wheel pit doors are being investigated. This system is still under design and it is still too early to disclose final information about its operation.

Although such situation is highly improbable, the TWIN-X6 is equipped with a TCAS, for "Traffic Collision Avoidance System". This system monitors the airspace around the aircraft and warns the pilot, directly on its navigation display, of the presence of other aircraft that may present a threat of mid-air collision.

No. The aircraft will warn you before making a belly landing. The TWIN-X6 is equipped with a GPWS, for "Ground Proximity Warning System", which automatically detects ground proximity. When the aircraft detects that the ground is near, it will warn you about it and ask you to pull up, or lower the landing gear, or select the water-landing mode.

Yes. The TWIN-X6 has enroute satellite weather displayed directly on the navigation displays.

MAD Aerospace Corp. aims to keep the TWIN-X6 under the Million US dollars threshold for the basic amphibious version. The pressurized version with full options will retail at about 1.5 Million dollars. Note that these prices will be updated in time according to the prevailing market environment.

Considering the assumptions below, the operating cost of a TWIN-X6 (or "variable cost") will be about 240$ per flight hour, 1.41$ per nautical mile, 0.23$ per seat-nautical mile.

Assumptions :

• Cruise speed = 170 knots.
• Engines = Mistral G300.
• Fuel cost = 5.20 $/US gal.
• Labor rate = 90$/hr.
• Maintenance time similar to modern Twins.
• 2018 component prices.
• All prices in US dollars.

Since the TWIN-X6 is a new aircraft, we can only estimate its resale value according to the market trends on similar models. That is, 3% annual depreciation in the first 3 to 5 years of life, followed by a 5% annual depreciation for the remaining lifespan. These numbers include a conservative inflation rate of 1.8%.

Considering a new TWIN-X6 that retails at 950 000$, the resale value can be estimated:

• After 5 years: 867 000$
• After 10 years: 737 000$
• After 15 years: 626 000$
• After 20 years: 532 000$
• All prices in US dollars.

Although the detailed listing of all the TWIN-X6 options and versions is not yet available, the following options will be offered:

• Engines: Mistral G300 (300HP) or G360 (360HP turbocompressed).
• Landing configuration: Land-only or amphibious, both with retractable landing gear.
• Pressurization: None, or up to 20 000 ft.
• De-icing: None, or present.
• Others: Air conditioning, custom seats, exterior and interior colors, 34'' wide-screen TV with sound system and video games, onboard Internet, heated seats and yoke, electrochromic skylights, refrigerated compartment for drinks and 2 tables that can be reclined into the side ledges.

The TWIN-X6 is also offered without the hull, making it a land-only plane. The aircraft will be lighter, fly farther, faster and will have a greater useful load. Our patented design is the first ever to offer such an option.

The TWIN-X6 is not yet open to pre-orders. The first round of pre-orders will be starting on June 17th 2019 at the International Paris Air Show "Le Bourget". MAD Aerospace will also be present at the "EAA AirVenture" in Oshkosh, July 2019.

In both shows, we will be presenting a full-size mock-up of the aircraft with finished interior trim and full glass cockpit. Come see us!

The float-wing configuration has been successfully used in many amphibious designs since World War 2, such as the Taylor Coot or the Beriev BE-103. With appropriate structural reinforcement, aircraft using a float-wing are usually qualified as "above average" for their water handling characteristics. Nevertheless, it remains a concept that is not well known to pilots.

High-wing seaplanes have a higher center of gravity. Experienced pilots know that these aircraft are exposed to nose-over when landing on water and have a tendency to capsize in strong crosswinds. In the TWIN-X6 design, the wing root enters the water and acts like a large sponson that stabilizes the aircraft laterally. The float-wing design makes it impossible to capsize on water and renders the TWIN-X6 unsusceptible to high waves when performing a 360 degree turn. The wing can also be used as a gangplank.

In addition, on low-wing aircraft designs with dihedral, an air cushion forms under the wing when it approaches the ground, giving the aircraft a stable self-centering behaviour. This aerodynamic phenomenon, coupled with our automatic stabilization system, prevents the wing tip from touching the water.

With its hydrodynamic V-hull with step, reversible pitch propellers and a water rudder, the TWIN-X6 is promised to have superior handling characteristics during all manoeuvres water.

For the TWIN-X6's unique engine configuration, one of the first aspects to consider was selecting an engine with the smallest frontal area as possible to improve the aerodynamics. Turbines were considered but their price exceeded what our target clients were willing to pay. The Mistral engine has the size of a turbine at the cost of a piston engine.

Putting aside its small size, the Mistral G300 engine has a long list of advantages that makes it an ideal choice for the TWIN-X6:

• FADEC: Single lever control and easy, dependable starts.
• Redundancy: Each engine has dual electronic control units, dual fuel pumps, dual injection systems.
• Multi fuel: 100LL avgas, leaded or unleaded mogas (US: 87, Europe: 92).
• No vibration: Wankel type engines generate no vibration which gives a true turbine-like smoothness.
• Lightweight: Even with all the equipment and the cooling system, the Mistral still ends up lighter than a 300HP piston engine.
• Liquid-cooled: Improved reliability, and never again will you have to worry about your exhaust and cylinder head temperatures.
• Turbocompressor: A turbo version of this engine is available, the G360, which is required for the pressurized TWIN-X6.
• Low maintenance: Very few moving parts and 3000 flight hours before overhaul.
• Reduction unit: Slower propeller rotation speed leads to higher efficiency and a 10db noise reduction.
• Robustness: Wankel type engines do not "break and fail" suddenly like pistons do... In the event of an internal failure, they slowly lose small amounts of power for many hours before you even notice something is wrong.

When selecting the powerplant equipment for the Twin-X6, we analyzed the trade-offs vs benefits of opting for a liquid-cooled system. On one hand, a liquid-cooling system adds weight and complexity to the aircraft. However, for us, it is a question of maximizing safety and reliability for our clients.

Let's consider the more common engine failures reported : Exhaust valve separates from the stem, exhaust seats falling out of the head, cylinder separation from the crankcase, piston and/or piston pin failure, broken rings, etc. Almost all of these failures are heat related. Too much heat induces stress, softens the metal, can cause detonation, and its related failures have cost many lives.

Liquid cooling stabilizes the engine temperature at its optimal level, and for us, heat control means safer flight. Some can choose to hold to obsolete concerns of the past, but at MAD Aerospace, we move forward improving the engine's reliability.

Liquid cooling has a long list of advantages compared to air-cooled engines:

• Good weight-to-benefits trade-off: The Mistral engine is so lightweight that even with the added weight of its cooling system, it still ends up lighter than an air-cooled engine of equal power.
• Reduced cooling drag: A radiator can be designed to present far less drag on the passing airflow than does an air-cooled engine with baffles.
• Stable engine temperature: For safer flying, and never have to worry again about your exhaust and cylinder head temperatures.
• Eliminates thermal shocks: While this problem is controversial, it surely doesn't exist with liquid cooling.
• Longer engine life: Lower and stable block temperature reduces heat related damage.
• Improved engine performance: The engine always operates at its ideal design temperature.
• Improved fuel efficiency: The engine can always operate at an ideal air/fuel ratio.
• Safer cabin heating: Exhaust gas cannot infiltrate the air conduits.

The TWIN-X6's radiators are located in the front half of each engine nacelle. The sleek, tight cowling improves the aircraft's aerodynamics; its internal ducting creates an optimal airstream to the radiator for efficient cooling. The radiators are positioned in such way that precludes direct impact with inbound flying objects such as birds.

For those who worry about potential leaks, simply consider that a liquid cooling system is less stressed by pressure and corrosion than an oil system is. If we can build reliable oil systems on aircraft, there is no doubt we will do even better for the liquid cooling system.

Mistral's FADEC system controls the electronic fuel injection and ignition systems. Its control algorithms are based on a single lever controlling engine power and on measurements of critical engine parameters such as engine speed and shaft position, manifold pressure and temperature, etc.

The system consists of two independent Engine Control Units (ECU). Each ECU is also constantly supervising the other. The two ECUs, as well as the pilot display and interface module, communicate via a CAN bus. In the unlikely event of a partial or complete failure of one of the ECUs, the other unit assumes full engine control and monitoring, and informs the pilot of the failure via both an alarm LED and a message on the display. In the event of an ECU failure, the maximum power is reduced to a level similar to a conventional engine operating on a single magneto.

Mistral's FADEC system is:

• Dual ignition and dual injection
• Easy, dependable starts
• Optimised engine settings in all flight phases
• Reduced operating and maintenance cost
• Increased overall operational safety

The Mistral engines are multi-fuel : 100LL avgas, leaded or unleaded mogas (US: 87, Europe: 92) will work.

The TWIN-X6 will only be offered with a full glass cockpit unless we obtain a strong demand for traditional VFR instruments. The final selection of the avionic suite has not been disclosed yet but we have a good idea of what it will be.

Amongst other instruments and options, the TWIN-X6 will include:

• Primary and secondary flight displays with SVT: Synthetic Vision Technology
• Dual Engine Data Monitoring Displays
• FADEC
• Dual single-lever engine controls
• Autopilot / Flight director
• Electronic stability assistance system
• GPWS : Ground Proximity Warning System
• TCAS : Traffic Collision Avoidance System
• Dual NAV/COM radios
• Satellite weather
• Angle of attack indicator
• SPS : Stall Prevention System
• Electrical trims
• Mode C transponder

Considering the G300 engines at sea level and the maximum take off weight of 6250 lb:

• Take off distance:    Land = 880 ft        Water = 1050 ft
• Over 50' obstacle:    Land = 1350 ft      Water = 1600 ft
• Landing distance:    Land = 750 ft        Water = 650 ft
• Over 50' obstacle:    Land = 1280 ft       Water = 1180 ft

MAD Aerospace is proud to announce that the TWIN-X6 unique design has no airborne minimum control speed limitation (Vmca, or Vmc) in an engine failure situation.

By design, the TWIN-X6 has its engines placed close to the centerline of the aircraft, which greatly reduces the destabilizing effect of an engine failure. Besides, the propellers blow into the tail's control surfaces, giving the pilot full control authority on the aircraft, even at low speed.

Should an engine failure occur, the TWIN-X6 will have a small tendency to yaw and bank toward the side of the inoperative engine, but that phenomenon will be much less aggressive than what it would be on a conventional Twin with wing-mounted engines. The pilot will be able to simply trim the yaw and roll controls to restore normal flight attitude. The remaining engine will have more than enough power to ensure safe flight with a good climbing capacity.

In final approach, with no minimum control speed (Vmc) to respect, the landing proceeds according to the normal procedures.

The structure of the TWIN-X6 is mostly made of composite materials, although aluminum and steel alloys are used where required. In general, the fuselage and the inner section of the wings are mostly made of carbon fiber, while the outer sections of the wings are made of fiberglass.

Our philosophy is that there is a right material for each part depending on its function and we do not believe in a single material beating all the others.

Yes. The TWIN-X6 is being designed for salt-water operation. All materials, resins and surface treatments are selected in order to respect this important design criterion.

The wings of the TWIN-X6 are aerodynamically designed to ensure a smooth and predictable stall at a high angle of attack, with easy stall recovery, to make it as forgiving as possible. Our aerodynamicist uses a combination of wing twist and custom airfoils to tailor the stall behaviour adequately.

However, it is our opinion that stalls and spins should be avoided. To that point, the TWIN-X6 is equipped with a SPS, for "Stall Prevention System". This system is standard on larger passenger aircraft but we believe it should be standard in every aircraft.

The SPS operates in 2 steps. First, when reaching a high angle of attack, the yoke starts shaking to warn the pilot of a potential stall. Second, if the pilot does not react and keeps increasing the angle of attack, an actuator engages and forces the elevator downward for a moment, pushing the aircraft's nose down.

Partially. The gull-wing of the TWIN-X raises the outboard section of the wing over the water, allowing deployment of 10 degrees of flaps for water takeoff and landing.

The maximum ceiling is 21 000 ft (6400m) with the G300 engines, and it will be higher with the turbocompressed G360 engines but the official engine data is not yet available to allow precise calculation.

The TWIN-X6 fuel system is fully redundant; no single failure can lead to the loss of an engine. The fuel is located inside the wings in 2 main tanks and 2 optional long range tanks, from which a total of 4 boost pumps ensure proper fuel supply to the engines.

Each Mistral engine is supplied by 2 distinct fuel lines connected to 2 distinct boost pumps, and each engine has 2 internal fuel pumps for its dual injection systems. The fuel tanks and lines are configured so that no single failure can lead to a complete loss of fuel.

Yes! The TWIN-X6 has a fully redundant electrical system. Even the alternators and batteries are doubled. Since the Mistral engines have specifically been designed to adapt such dual electrical system, why not include it.

The TWIN-X6 is not only designed for private pilots; it will be sold to aero-taxi companies or for medivac missions, which requires dual controls.

In addition, most of the potential private clients we interviewed asked for it! We are considering the possibility of offering a "single control" version if the market demand justifies it.