VTOL - Vertical Take Off and Landing
VTOL, vertical take off and landing, enables a traveler to travel directly from point A to point B, instead of going from point A to an airport in a car say, then fly from the airport to another airport, and then drive with a car from the other airport to point B. Not only in travel is VTOL very useful, in rescue operations as well as in military and law enforcement applications it is often supremely important to be able to touch down and take off from a spot, rather than an airfield/airport.
VTOL is an issue that has been considered about as long as humans dreamed about flight. Shown in the picture left is how Leonardo da Vinci envisioned a VTOL craft powered by a giant screw, not dissimilar to the idea of a helicopter.
VTOL is challenging. It is far more technically difficult than conventional winged flight, but in exchange, it has several advantages.
Time and fuel savings: Vertical take off and landing enables an aerial vehicle to take off from many more locations than an aircraft that requires an airport. This means that the journey to and from the airport can be eliminated, saving time and fuel. A person in the US lives an average of 17 miles / 27 km away to the next airport. But she or he lives on average less than 1 mile away from a location that is suitable for vertical take-off and landing of a small civilian VTOL craft like SkyCruiser. Importantly with VTOL the 17 miles / 27km are saved on both ends of a journey
Efficiency and speed: For personal aircraft the the wing is typically constructed with a compromise in mind. Typically it is desired that personal airplanes can take off and land at fairly low speeds such as 100kph (62mph), so that they can use small regional airfields, for example. On the other hand speed and efficiency are desired, but an overly large wing is a hindrance to this. Since lift (like drag) increases with speed, a very large wing at cruise speed generates more lift than needed, requiring the pilot to trim the elevator down, causing drag. The large wing itself, is also causing drag due to skin friction, and the larger it is, the more 'skin' is in contact with the air, the more drag is caused, the slower the airplane can fly and the more fuel it burns. A VTOL plane can be built such that its wings are optimized strictly for speed and efficiency since take off and landing are not handled by the wing. If the VTOL components in turn do not cause much additional drag, then real net drag reductions can be achieved making the plane faster and more efficient than even a pure aircraft.
Safety: More than 85% of all airplane accidents (and fatalities) happen during their conventional take off and landing. The initial climb and the final descent are the most dangerous segments of a flight. An aircraft is safest when cruising at high altitude. It is most vulnerable when flying close to the ground or rolling on the ground at high speeds because the margin for error and error recovery is small to non-existent. This is why take off and landings are comparatively dangerous, even on airports with their vastly long and empty runways. Vertical take off and landing greatly reduces this risk because the plane is accelerated and decelerated while high in the air adding margin for error and recovery. This makes already safe air travel even safer.