VTOL 101: The Ultimate Guide to Vertical Take-off and Landing pt. 1
This is part 1 of 4 in our VTOL 101 series
Aviation is the driving force behind our growing global economy; it enables the transport of people, products, and equipment to any location on the globe. Aviation brings together people, colleagues, families, and friends. But, each year, as our population rapidly grows, it is becoming more and more evident that, if we are to meet the needs of our increasingly crowded world, we must secure methods of transport that are agile, safe, convenient, and both environmentally and financially sustainable.
However, runways are expensive, and many locations aren’t able to accommodate the horizontal space that they demand. As a result, our future aircraft will have to be able to take-off and land from a single spot. This will require advanced VTOL (vertical take-off and landing) technologies that are capable of high-precision end-to-end travel. Achieving this is no small task. In fact, in previous decades, the widespread deployment of VTOL fleets was little more than fantasy, as excessive price tags made financing the necessary research and development all but impossible. The same cannot be said today.
A convergence is occurring across a number of sectors. Diverse industries are rushing together to accelerate our aeronautical capabilities exponentially. Material science and manufacturing have dramatically reduced production costs. NASA’s Unmanned Aircraft System (UAS) Traffic Management (UTM) proposal does not overwhelm current air traffic management or compromise safety. Consumer experience with “on-demand” ride sharing will naturally expand to the air. These advancements are making it practical to build a new class of VTOL technologies.
We have, in short, reached a turning point in both our manufacturing capabilities and the saturation of our transportation industry. When these two things are considered together, one thing becomes clear: The need was never greater, and the moment was never better — the time for VTOL is now. For the population as a whole, vertical take-off and landing is the difference between millions of hours wasted on sub-optimal forms of travel and the freedom of mobility.
What is VTOL?
VTOL stands for “vertical take-off and landing.” As the name implies, it denotes a kind of aircraft that can launch and land from a single spot. Since aerial vehicles equipped with VTOL technologies don’t require the horizontal space of a runway, they can start and end from virtually any location on the globe.
They could take-off from a ship, pick up passengers waiting in a forest clearing or a city parking garage, and come to rest on top of a building. The number of potential combinations is nearly infinite.
Traditional aircraft, by contrast, need a great deal of space to take-off and land. They require runways, airports, and similar landing structures to function. These features preclude traditional aircraft, like planes, from operating in many locations that VTOLs can navigate easily.
How Does VTOL Work?
At its core, the science that governs VTOL aircraft is the same science that regulates traditional aerial vehicles. All flying machines operate by generating lift, which is the force that counteracts the weight of the aircraft in question. To get a little more technical, lift is the force that is produced when a solid body (such as a wing, blade, or jet nozzle) changes the direction of the air that it encounters. As air is turned, lift is generated in the opposite direction, causing the aircraft to rise.
The helicopter is the most common and well-known design; however, it’s far from the only VTOL aircraft in operation. Broadly speaking, there are two kinds of VTOL technology that are in service today. These are the rotorcraft and powered-lift vehicles.
Rotorcraft: helicopters, quadcopters
The rotorcraft, or rotary wing aircraft, generates vertical lift using blades that revolve around a central mast. A number of blades mounted on a single mast are referred to as a “rotor,” hence the name “rotorcraft.” A helicopter’s blades are curved on top and slightly flatter on the bottom. This shape makes the airflow over the top of the blade faster than the air flows under it. This is where something known as the Bernoulli Principle comes into play.
Ultimately, this principle describes how the speed of air and pressure of air are related. In short, when a helicopter’s blades rotate, there is less air pressure on top of the blades, which causes suction and makes the aircraft rise.
Notably, rotorcraft depend on their rotors to sustain their lift throughout the duration of their flight. This is ultimately what separates them from the other major classes of VTOLs.
Powered-lift: convertiplane, vectored thrust vehicles
Powered-lift vehicles are aircraft that take-off and land vertically and depend primarily on nonrotating devices (fixed wings) to sustain their lift during horizontal flight. Such aircraft may, however, deploy rotors to drive their lift during their launch and landing operations.
For example, there is the Bell Boeing V-22 Osprey. It’s a kind of powered-lift vehicle that’s known as a “convertiplane.” It uses rotors for its launch and landing stages but traditional, fixed wings during normal flight. The Harrier Jump Jet is another kind of powered-lift vehicle known as a “vectored thrust aircraft.” It operates by manipulating the direction of thrust from the engine, as opposed to rotors, to control the vehicle during take-off and landing. Like the Osprey, the Harrier uses traditional, fixed wings to generate lift during horizontal flight.
Other classes of powered-lift flying machines include the lift jet, tail-sitter, and lift fan. Despite the fact that a number of experimental variants of these designs were flown in test flights, none of the concepts ever made it into production or were used operationally.
Read Part 2: VTOL v.drones, UAVs, Flying Cars and more
— — —
This is part 1 of our VTOL 101 series, thank you for reading. In our next post, we’ll be covering the difference between VTOL, drones, UAVs, Flying Cars and more. Stay tuned!
If you have any questions and/or just want to say hello, reach out. We love speaking to enthusiasts, investors, engineers, and anyone who loves flying!
