Terrafugia TF-X – The Flying Car

With airplanes, we could traverse long distances quickly but not taking us exactly where we want to go but to the nearest airport mostly while sharing the ride with other passengers. Cars will take us to a more precise location as long as it is connected by a road, but at a much slower pace. The fusion of these two technologies will get usa hybrid which retains a portionof the positives from both sides, leading to the birth of the “Flying Car”. This technology has been promised to us by the early 21st century, since the early 1950s as seen in various articles and sci-fi movies. Although the idea has been around for a long time, it could not be converted into a tangible product since it was more complicated than that which met the eye. Nevertheless the year 2015 has seen a solid step-forward in creating a ‘car-o-plane’ when American company Terrafugiabased in Massachusetts, have released their final design of the flying car concept ‘TF-X’ which they expect to come out some time in the next 8 to 12 years. In this article we will understand how this particular flying car will work and its interesting features and innovations to overcome the various challenges faced in this Aero-Automobile.

1 HOW DOES IT WORK?

The TF-X is capable of seating 4 adults which is usually the capacity of an average hybrid car. It has a foldable wing type, rotor blade propelled aeronautical system powered by a gasoline engine when it is in the air and an electric motor when it is on the road. The rotor blades will charge the battery of the electric motor while they are running.

1.1 THE EXPERIENCE

The wings, located on top of the rear end, fold into the side of the vehicle. The rotor blades with a variable angle of attack are located at the tips of the wings. When the pilot wishes to take off, the foldable wings deploy at the push of a button in a matter of seconds. The steering wheel of the car folds in and out pops a flight stick to control the avionic systems. The rotor blades turn upwards to provide an upward thrust for a straight vertical takeoff negating the requirement for a runway. Once in the air, the blades turn forward to provide forward thrust. Once the vehicle reaches its peak velocity at cruise speed, the propellers shut off to conserve energy. Terrafugia claims that training to fly the TF-X requires only 5 hours but, there is a handy autopilot system which will take over for you if you desire so. When the vehicle is ready to land (vertically), flaps deploy to reduce the speed and the blades return to the vertical position to provide a soft landing.

he TF-X in drive mode

1.2 WHAT POWERS IT?

The power systems of the TF-X consists of two electric motors coupled with a 300bhp petrol engine which can provide a combined output of a MegaWatt of power (which is quite a lot of energy). The power transmission system present inside the TF-X will allow it to soar at a maximum speed of 200mph and cruise speed of 160mph providing flight ranges of about 500 miles. The twin electric motors will assist the rotor blades during takeoff and landing at vertical thrust configurations. During cruise conditions the fan blades will fold back into an aerodynamically efficient shape while a rear end fan provides the cruise thrust. The rotary motion from the fan blades will also be used to recharge the electric drive motors during cruising.

The Vertical Takeoff and Landing Mode of the TF-X

1.3 WHAT CONTROLS IT?

The onboard electronic systems are the basic equipment found in general aero-vehicles. A gyroscope to sense orientation, a pitot tube for airspeed, barometers, altimeters, GPS location systems, tachometers, hydraulic control systems for pitch, yaw and roll and various other sensors, controllers and actuators required for autopilot functions. The on road controls are the normal ones which you would find in any plug-in hybrid vehicle which are already available. Steering when and accelerator-brake pedal configuration of on road driving and stick and rudder pedal configuration for flight control are present on board.

Figure 3The TF-X in Cruise flight mode

1.4 WHAT SHAPES IT?

Coming to the structural design perspective, the size of the aero-car (or the car-o-plane) is small enough to fit inside a regular single car garage. The foldable wings are mainly responsible for this as due to this reason it does not require the user to own a separate hangar for this purpose. Material for the TF-X has to be very light and for this reason carbon-fiber body is used around a steel chassis to support the avionics and transmission systems. The foldable wings on the outside and the foldable steering systems on the inside are controlled by electromechanical folding mechanisms

2 THE PROTOTYPE TF-TRANSITION

Figure 4The TF- Transition test runs during land and flight mode

A prototype has already been built by Terrafugia used to test its concepts and the TF-X model will only improve on the results obtained. It has undergone many test runs successfully, both on road and airborne conditions. The Transition although uses a gasoline engine to power both the propellers in air and the transmission drive train on road. It differs from the later released design concept TF-X by, the foldable wings are present at the lower side; single propeller at the rear end and a double tail configuration. The transition proved the concept of a flying car successfully leading test results which will only improve the design results as applied on the TF-X. The specification of the transition as released by Terrafugia are shown in the below table.

Cruise Speed	100 mph (160 km/h)
Range	400 mi (640 km) plus 30 min. reserve
Takeoff Roll	1700 ft (518) over 50 ft obstacle
Useful Load	500 lbs ( 227 kg )
Fuel Burn at Cruise	5 gph (18.9 L/h)
Usable Fuel	23 gal ( 87 L )
Mileage on Road	35 mpg (6.7 L / 100 Km )

Table 1Specs of the TF-Transition

3 THE VERDICT – WILL IT CATCH ON?

Will the flying car be a part of the Modern household?

This is the biggest question in hand with the flying car concept in general. The idea has been around since a long time but has not been implemented so far which means that it has many factors hindering its application. Although it just seems like attaching a propeller blade to a car and making it fly, it is a lot more complex. For instance, the aerodynamics of a car (a very fast one) is primarily to keep it on the ground and allow air to glide through it, while the aerodynamics of an airplane is get the maximum lift off of the airfoil. At the current state of transportation, it is hard to say whether this will catch on primarily since this mode of transportation doesn’t exist practically yet. We can hardly scratch the surface of the problems and complications which will arise, like the traffic rules and monitoring (air traffic policing). Therefore the approval of such a product by national aviation authorities might take a long time once the actual product is released which will add to the time we see a street (and air) full of car-o-planes.

Now coming to the other side of the coin, the safety features which are aimed to be implemented on the TF-X like the autopilot feature, full vehicle parachute deploymentin case of emergencies will probably make it safer than a modern day automobile as claimed by Terrafugia. The automated pilot will also help in directing it away from bad weather patches, heavy traffic and restricted airspaces. The high level of automation does not restrict the user control necessarily since it can be switched off at any time if the user finds it not to be the optimum decision. The best part is that the absence of land or a road will not hinder the person from reaching his/her destination. The world will be more connected using the flying car and will start a new era of transportation which might simultaneously pull down the demand in the airline sector.

In terms of cost Terrafugia only claims that it might be in the same bracket as a high end luxury automobile. In theory it all sounds good, but anyone who enters in the development of flying will have to spend most of their effort convincing the public to buy them, the government to allow its use and the lawmakers to make a completely new set of rules to govern it. Imagining a period when all the black and white work done, the flying car might be an attractive thought when you step out onto the open. It is very well in its early stages of development as it is proved by what we have so far is a rendering animation as to how the product will look and work. So let’s just sit back and wait for the future to arrive at our parking cloud.