There are drone models that are not at all suitable for transporting payloads and large drones that can carry payloads of several 100 kg. The intended application naturally plays a major role here. For a simple image or a semi-professional tracking shot, multicopter drones in a class under 5.0 kg are recommended. However, individual applications are often pursued where the payload alone is already 5.0 kg. In this case, more powerful systems with a higher take-off weight must be used.
The decision between a multicopter and a fixed-wing aircraft (often referred to as fixed-wing or fixed-wing aircraft) must be made. If hovering on the spot, possible indoor use or vertical take-off and landing are required, there are many arguments in favour of using a multicopter. Due to their relatively simple mechanical construction and wide range of applications, multicopters have the largest market share among professional drones used in civilian applications. If, on the other hand, longer distances are to be travelled, the obvious choice is a fixed-wing aircraft. There is also the growing category of hybrids, which combine the characteristics of multicopters and fixed-wing aircraft, also known as VTOLs (vertical take-off and landing).
Flight timeFlight time is a constant topic in the drone industry. In general, it can be said that proven flight systems have a flight time of around 20 minutes. However, there is a big difference between a fixed-wing aircraft and a multicopter. Due to the dynamic lift of the wings, the fixed-wing aircraft naturally requires less energy to "fly" and therefore achieves flight times of well over an hour. However, the advantage of a multicopter is obvious: it can take off and land vertically.
Field of application
The same applies to drones: there is no such thing as a jack of all trades. If you want to carry out inspections on facades or many flights take place indoors, then the system should be small and have optical obstacle detection. However, small drones are less visible at long distances, so it is advisable to use slightly larger devices for survey flights, for example. When flying beyond visual range, it is important that the drone has safety features and is fail-safe. This is achieved, for example, by using 2 batteries or a high number of drives (e.g. octocopters). If a drive fails, the drone can return safely to the starting point.
When flying close to obstacles and/or at high wind speeds, a multicopter with lightweight, smaller rotors is often the best choice. Contrary to popular belief, smaller drones (approx. 1.0 kg) are equally or even less susceptible to high wind speeds than larger devices (over 3.0 kg). This is due to the smaller surface area exposed to gusts of wind or turbulence. The heavier the flight systems are, the more sluggish the flight movements are due to the inertia. This can be an advantage in some applications. In general, it should be mentioned that the flight stability of most drones in the hobby and professional sector is sufficient for many applications. Settings can also be made individually here, but are often not relevant.
Legal basisIn principle, commercial drone flying is very well regulated in Germany. Depending on the take-off weight, there are a number of things you should be aware of. Details can be found in this FAQ. In general, it can be said that with a flight weight of less than 5.0 kg, many missions can be carried out without a special permit or individual ascent authorisation.
Sensor / camera system
Now it is important to know which camera is most suitable for the planned missions. There are a number of very well-functioning camera systems available on the market for this purpose. The camera is mechanically suspended using a so-called gimbal. This suspension with small electric motors ensures a wobble-free, straight camera image, as the movements of the drone must be decoupled from the camera. Most RGB (visible colour spectrum) cameras have a resolution of 12 MP or more, which is perfectly adequate for many applications. The cameras are often permanently attached to the drone and therefore cannot be changed. Changing lenses is only possible with models in higher price ranges. With special zoom cameras or lenses, the level of detail can be significantly increased and damage can be visualised during an inspection, for example.