Unmanned gliders are very popular, especially within the radio/remote controlled (RC) enthusiast community for leisure flying and long-distance racing competitions.
What are unmanned gliders/sailplanes?
Unmanned gliders/sailplanes are fixed-wing drones/unmanned aerial vehicles (UAVs) that are used in recreational and/or competitive activities. These aircraft can be powered (motor gliders) or unpowered (conventional gliders) and must be controlled in flight.
People typically refer to this sport/activity as gliding, soaring, or sailplaning.
Take note that this post will only be focusing on unmanned gliders that are considered drones. This excludes free flight gliders which are unmanned but are not considered drones as they are not controlled in flight.
- How Do Unmanned Gliders Work?
- What Are The Types Of Unmanned Gliders?
- What Are Unmanned Gliders Used For?
- What Parts/Components Make Up Unmanned Gliders?
- What Are The Advantages And Disadvantages Of Unmanned Gliders?
- What Are Some Examples Of Unmanned Gliders?
How Do Unmanned Gliders Work?
Unmanned gliders/sailplanes use the reaction of natural rising air (updrafts) flowing against the robot’s lifting surfaces (wings, empennage etc) to generate lift and fly. Powered motor gliders use their propulsion system only for takeoff and/or in an emergency.
These updrafts can be formed when air is forced up the side of a steep hill or mountain, or at weather fronts where warm and cool air collide. Typically, they can form anywhere simply because hot air rises.
The glider’s wings/airfoils are sized and shaped in a way that captures airflow as the aircraft’s airspeed increases which thus produces lift.
These drone’s wings need to have long wingspans in order to capture as much airflow as possible while being as thin as possible in order to reduce drag. The fuselage also needs to be designed in a way that reduces drag which is typically achieved by making it thin.
The glider’s parts/components need to be lightweight to maximise flight time by reducing the vehicle’s weight.
Glider unmanned aerial vehicles (UAVs) are a subcategory within fixed-wing UAVs.
Check out our full post that dives further into how fixed-wing UAVs work, the differences between fixed-wing and rotary-wing UAVs, fixed-wing drone applications, parts/components that make them up, advantages/disadvantages, powerplants used in them and some real examples:
Motor gliders are designed much in the same way, except for the fact that they have additional internal components which is a propulsion system. This typically includes propellers, motors, and a battery.
How do unmanned gliders/sailplanes takeoff?
Unmanned gliders/sailplanes can be launched using various methods. These include:
- Launched by being thrown
- Launched via a catapult launcher
- Launched by an aerotow
- Launched from another powered aircraft
- Self-launched via a runway
Glider unmanned aerial vehicles (UAVs) that are thrown/hand-launched are typically small and lightweight drones that can easily be carried in one hand. The operator only needs to throw the glider from a high enough altitude.
Drone gliders that are launched via a catapult launcher are typically a little larger than hand-launched drones. These UAVs cannot be easily carried by one person if not at all. The launcher catapults the drone into the air where the UAV then sustains flight.
An aerotow involves a powered, often manned, aircraft that transports the unmanned glider using a tether from takeoff to a specific altitude where it then detaches it.
Check out our post where we dive into what drone tethers are, the different types, uses, advantages/disadvantages, materials they’re made of, costs, examples and more:
Related Post: Drone Tethers Explained: What They Are & How They Work
Unmanned gliders that are launched from another powered aircraft (often manned but can be unmanned) are typically physically mounted to the powered aircraft and released once it has reached its target altitude.
Unmanned gliders that can self-launch themselves only include unmanned motor gliders that use their propulsion systems for the takeoff process.
What Are The Types Of Unmanned Gliders?
Here are the two types of unmanned gliders/sailplanes:
- Unmanned gliders (unpowered)
- Unmanned motor gliders (powered)
Conventional unmanned gliders are typically considered to be unpowered drones.
Unmanned motor gliders/sailplanes are unmanned gliders that are equipped with a propulsion system typically in the form of a propeller, motor, and battery which is only used for takeoff and/or in an emergency.
Check out our full post that dives into each type of fixed-wing drone/UAV. For each type, we explain what they are, how they work, their sub-types, what they’re used for, a benefit and drawback, and two examples of each:
Related Post: Types Of Fixed-Wing Drones/UAVs Explained (+Pictures)
What Are Unmanned Gliders Used For?
Here are 5 applications for unmanned gliders/sailplanes:
- Unmanned spacecraft can be used as gliders in the re-entry process
- Research purposes for long-distance flights as long as they do not require heavy payloads
- Used as trainer aircraft to help teach beginner drone pilot’s how to fly an unmanned aircraft
- Long-distance/cross-country races in the RC community
- For fun by enthusiasts who love flying. This inculdes using them for aerobatics
Check out our full post on several fixed-wing UAV applications where we explain what each is, how fixed-wing drones are used in them, how they’re beneficial typically over manned aircraft, and some real examples/concepts if there are any:
Related Post: 12 Awesome Fixed-Wing Drone/UAV Applications Explained
What Parts/Components Make Up Unmanned Gliders?
Unmanned gliders/sailplanes are made up of several parts including a fuselage, wings, tail assembly/empennage, and landing gear/undercarriage.
The wings typically include ailerons and wingtips (increases efficiency by reducing drag caused by vortices).
A conventional tail assembly/empennage is made up of elevators and a fin acting vertically, and a rudder and tailplane which act horizontally.
The landing gear/undercarriage is almost always made up of skids.
Typical components include a transmitter, receiver, servos, lights, and sometimes an inertial navigation system (INS).
Unmanned gliders are fixed-wing UAVs, therefore they have most of the same parts and components.
We’ve gone into far more detail in our article where we explain what each part and component of a fixed-wing UAV is, how it works, the different sub-types of each component (if any), and some real examples:
Related Post: Main Fixed-Wing Drone/UAV Parts & Components Explained
What Are The Advantages And Disadvantages Of Unmanned Gliders?
There are several advantages and disadvantages of unmanned gliders/sailplanes. We’ve split these up into two separate sections below.
Unmanned glider/sailplane advantages
Here are 5 unmanned glider/sailplane advantages:
- Theoretically they can have near-infinite flight times
- They’re very efficient in generating lift
- They’re easy to transport as they’re typically very lightweight and easy to disassemble
- They’re very cheap due to little maintenance fees because they have few components
- They’re very quiet and eco-friendly
Unmanned glider/sailplane disadvantages
Here are 4 unmanned glider/sailplane disadvantages:
- They’re typically slow
- They can be difficult to operate as you need to learn where to find updrafts
- They can be fragile as manufacturers may sacrifice durability for a reduced weight in the manufacturing process
- They allow little room for error during flight as it could lead to a crash
Check out our post that explains all fixed-wing UAV advantages and disadvantages:
What Are Some Examples Of Unmanned Gliders?
Here are 9 examples of unmanned gliders/sailplanes:
|Papageier||Claus Hohmann||Unmanned glider (unpowered)|
|Silizi Solar||Horst Groner||Unmanned motor glider|
|Aquila||Airtronics||Unmanned glider (unpowered)|
|Model V||Eclipson||Unmanned motor glider|
|Xenia||Franz Wilhelm Hefner||Unmanned glider (unpowered)|
|Die Turbiene||Klaus Kurt||Unmanned motor glider|
|Larus||Franz Wilhelm Hefner||Unmanned glider (unpowered)|
|Ninja||Michael Schubert||Unmanned motor glider|
|Esprit||Matthias Segerer||Unmanned glider (unpowered)|
If you’d like to discover who the best drone companies are in the world for the consumer, commercial and military drone markets and some fun facts about them, we have a full post on this topic below:
Unmanned gliders have been around for a long time. They are built and used by many as they’re really cool. It’s incredible that an aircraft can stay in the air for so long without a propulsion system!
As we’ve already mentioned, unmanned gliders are a subcategory of fixed-wing UAVs. We highly recommend you check out our main article here on what fixed-wing drones are to learn more.