Aside from more fuel usage, what makes VTOL planes so much more difficult to manufacture and utilize?
In: 3
Hover involves an environmental condition called “Ground Effect” where the air stops acting like a fluid, and it gets a springy property. The computers have to deal with this and make automatic adjustments.
Flying a helicopter, or any vertical lift craft, involves more degrees of freedom, and the pilot has to manage them separately. Your toy drone uses an onboard processor to eliminate some degrees of freedom, but that reduces the operating envelope.
This adds complexity and generally additional weight. This added weight and space taken up by the complexity can be used for other things.
Traditionally airplanes are not designed to operate at low speeds and require additional controls to allow for maneuverability. Again adding to the complexity.
You also need to provide thrust in multiple vectors unlike a traditional aircraft.
The complexity of getting a airplane to hover then start moving forward then stop moving forward and resume hovering and the amount of stress that puts on the frame of said airplane are a large reason. You can’t forget when the plane is hovering the wings don’t generate lift so your using the eng to completely lift the plane off the ground in a controlled manner. All a normal plane has to do is move forward fast enough to have the wings lift the plane off the ground. The engine them self don’t actually push the plain up so much as forward let alone be the main source of directional control.
To hover you need to provide the same thrust as the weight of the aircraft. The relationship is called a TWR(thrust to weight) and needs to be above 1.
Airlines have a TWR of around 0.2-0.3 when you do a takeoff at max weight. So to have the engine power to do a vertical takeoff fully loaded you need somewhere between 3-5x the engine power, that is if the engine does not add any weight. So for something like a airline or cargo aircraft a chance to be able to do a takeoff like that requires a lot more power. This is without any complication of being able to redirect the thrust downwards and keeps steady.
You need something like a fighter jet to start to get enough thrust. Fighters’ jets are percentage-wise a large part engine. But even then you have to reduce the fuel and/or weapon loadout.
A AV-8B Harrier II Plus has a max rolling takeoff weight of 14.1 tonnes compared to 9.4 tonnes vertical. This is an aircraft that have an empty mass of 6.6 tonnes. So they were used on ships with a rolling take off with or without jumps to you can use both the engine thrust and wings for lift. It is at landing when you are a lot lighter you do vertical lading.
The F-35B replacement is only considered a STOVL (short take-off and vertical-landing) aircraft. It can take off vertically but not with a lot of fuel or payload. The stated intended usage is if it is required to reposition it for short rolling takeoff are refueling and rearming.
So a VTOL aircraft will be in large part just engines and what is required to change the airflow vertically. This makes a general idea quite useless. The usage of aircraft that has been built and the new design is STOVL because that is how the old aircraft were used and works on small carriers. Small carriers are the only reason for aircraft like that.
If you what vertical takeoff and landing the answer is a helicopter or tiltrotor aircraft like a Bell Boeing V-22 Osprey
Latest Answers