Waypoints: From highway to airway

May 1, 2009

Editor in Chief Thomas B. Haines owns and flies (but does not drive) a Beechcraft A36 Bonanza.

Plenty have scoffed at the notion of a flying car and it seems that over the years nearly an equal number of enthusiastic inventors have attempted to prove the scoffers wrong. Molt Taylor’s Aerocar was only one of about two that ever received a type certificate. In fact, his is about the only one to ever even fly. Most never leave the drawing board—or these days, the CAD display.

But a team of young, energetic engineers trained at the famed Massachusetts Institute of Technology (MIT) broke that trend on March 5 when their Terrafugia Transition “roadable airplane” (don’t call it a flying car) lifted off the two-mile long runway at New York’s Plattsburgh International Airport. As planned, the four-wheel Transition raced down the runway, leaped into the air, and flew just above the runway, touching down again before the end of the pavement. Test pilot Phil Meteer, a retired U.S. Air Force fighter and test pilot, reports that the airplane handled as predicted after dozens of high-speed taxi tests and thousands of hours of simulator and wind tunnel testing.

After the first runway flight on March 5, the airplane went through an extensive inspection before it flew six more times on March 7. Meteer reported that all seven landings were smooth and predictable, touching down in a typically nose-high attitude. “Pilots will love the ground handling,” Meteer said at a media event at the Boston Science Center on March 18. Although light airplanes typically seem a bit ungainly while on the ground, the Transition rides on a four-wheel suspension designed to handle Boston-style potholes.

The Transition is the brainchild of a group of engineers led by Carl Dietrich. Dietrich, his wife, Anna Mracek Dietrich, and the other engineers formed Terrafugia to develop a light sport aircraft that solves four of the shortcomings of other light airplanes. Carl Dietrich, a low-time VFR pilot, quickly learned that travel by light airplane has many obstacles to overcome, including weather sensitivity; ground transportation challenges upon landing; long door-to-door travel times including shifting between vehicles and moving bags and gear from car to airplane and back to car again; and high cost. The Transition, he says, addresses all four of those obstacles.

As an aircraft in the light sport category, Transition cannot fly in instrument weather conditions, so the pilot solves the weather-sensitivity issue by landing ahead of the weather and then driving beyond it. Ground transportation issues are solved because once you land, you can fold the wings and drive to your ultimate destination; door-to-door time is reduced because bags are handled only once and transition from car to airplane or back takes only 30 seconds; high cost is addressed because Transition gets 27 mpg in the air and 30 mpg on the ground and the owner can keep the vehicle at home in a single-car garage rather than an expensive hangar. Dietrich noted that there is a six-year waiting list for hangars at his airport, Hanscom Field in Bedford, Massachusetts. When you can get a hangar, they rent for $1,200 a month.

Of course, all of this comes at a projected price of $194,000 for a Transition when they are scheduled to start deliveries in 2011. That price point certainly puts it at or near the top of the list of light sport aircraft already in the field, but it certainly offers a level of flexibility not afforded a traditional airplane.

What makes it fly

The Transition is a two-place aircraft made of mostly carbon fiber. A 100-horsepower Rotax 912S engine sits “under the hood” just ahead of the cockpit. A long carbon-fiber drive shaft transits the area between the two cockpit seats to a fixed-pitch composite pusher propeller in the back. The engine can burn either auto gas or avgas, although it prefers auto gas. A pair of rudders and vertical fins protect the propeller on the ground. However, the propeller is stopped when in ground mode. Then the Rotax powers the vehicle’s front-wheel drive system. Just aft of the vertical fins is an elevator. Out front, a canard also acts as a car bumper. The canard does not move, but it carries an electrically actuated elevator trim tab on the aft chord. The 27.5-foot wings house conventional ailerons; there are no flaps.

In the road mode, the vehicle from the front looks a bit like a Volkswagen Beetle with some additional appendages. Rather than enclosed in conventional fenders, the two front wheels are outboard of the engine compartment in fairings festooned with automotive-style struts, somewhat like the Plymouth/Chrysler Prowler. To switch from airplane to road mode, the vehicle must be stopped. The pilot throws a couple of switches and the wings fold up from the middle and at the root, collapsing next to the aft cockpit to a width of six feet, eight inches. To switch back to airplane mode, the vehicle must be stopped and the pilot must enter a personal identification number on a keypad next to his left knee and then swiftly move a lever on the center console to actuate electrical/mechanical interlocks to deploy the wings. In less than 30 seconds, the wings unfold. The PIN requirement is a security step to help prevent nonpilots from stealing the vehicle and attempting to fly it. Visible wing-root attach points and a bow-tie-shaped wing center joint latch as well as a shake of the ailerons show that the wing is fully deployed and latched for flight.

Inside, the pilot has a conventional steering wheel along with brake and accelerator pedals for ground mode. For airplane mode, he pulls up on a control stick collapsed between his knees and moves his feet outboard to two conventional rudder pedals. Aircraft power is managed with a center-mounted throttle control. In the current proof-of-concept vehicle, the center stack houses a multifunction display, a Garmin SL30 VHF nav/com, and a Garmin transponder. A Garmin 496 GPS sits on the glareshield/dash—handy for ground and air navigation.

A whole-airplane ballistic recovery system parachute will be an option on the Transition.

Going forward

In addition to further refining the vehicle with an expanded flight test program, the group is challenged with meeting certain automotive regulations. Because of its small planned production run and the small size of Terrafugia as a company, the U.S. Department of Transportation does not require the company to conduct expensive automotive crash tests, although it must show a plan for doing so in the future as the company matures. Dietrich is still working with the EPA to show the agency that the Transition is an airplane first. If it is determined to be a car, it must meet automotive emission requirements, which the Rotax will not meet. Dietrich says he is well along with all of the affected agencies in determining what must be done to meet the requirements to complete the project.

The team knows it will need to make some modifications to the proof-of-concept vehicle before it completes a prototype, which is already under construction.

The company has more than 40 orders for the vehicle, reserved with $10,000 refundable deposits. Most of the position holders are pilots.

Dietrich says Terrafugia is “poised to become a catalyst to usher in a new era of transportation,” although he recognizes that a roadable airplane is just a small niche within the small niche of light sport airplanes.

The light sport category was developed in part to foster innovative ways to address the varying needs of pilots. The unusual Transition certainly meets the definition of innovative.

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