Terrafugia, the Woburn, MA, company developing the Transition flying car, has plans for a vertical take-off and landing (VTOL) sibling. The proposed Terrafugia TF-X would be a tilt-rotor flying machine that would take off and land like a helicopter. Instead of a runway, the TF-X could use a helipad or parking lot. That’s important because Terrafugia’s devices aren’t so much flying cars as roadable aircraft that take you from the airport to your destination a few miles away. The closer you land to your destination, the better. Don’t sell your Cessna 400 just yet. The TF-X is a decade away and will likely cost on the high side of a half-million dollars. Maybe a million.
The Terrafugia TF-X is a small fuselage with four road wheels on the bottom, along with stubby wings with electrically driven rotors that point vertically for liftoff, then rotate horizontally for level flight. The transition from vertical to horizontal flight is tricky in a VTOL plane. Terrafugia says the TF-X electronics manage that, as well as the rest of the flight. In other words, the pilot decides when to lift off — and how high — before starting to fly horizontally, and the plane actually manages those orders. That’s not unusual; some military aircraft wouldn’t fly without computers controlling stability.
Propulsion appears to be a gas turbine for horizontal flight and hybrid electric for ground travel. For liftoff and landing, the rotors would be turned electrically via a generator and battery storage, as would the road wheels.
The TF-X appears to work much like the Marine Corps V-22 Osprey, which is good news because the technology now works, the defense department says, and bad news because early Ospreys crashed a lot and the project ran over budget. Thirty years after the concept Osprey project kicked off, the Marine Corps now says its fleet has half the accident rate of other Marine aircraft. (The Marines have most of the 140 or so Ospreys deployed.) The Osprey carries 24-32 soldiers at a cost of about $70 million, about twice as much as the cost of a helicopter with the same payload.
The Terrafugia TF-X has been described as a nearly vertical take-off and landing aircraft, needing an area with a diameter of about 100 feet. That’s still easier to find than a 2,500-foot runway.
Author: Bill Howard