There are rules that govern the operation of drones in all/most countries. In the USA, the Federal Aviation Administration (FAA) regulates all aspects of civil aviation. In Europe, it is the European Union Aviation Safety Agency (EASA). In the UK, it is the Civil Aviation Authority (CAA). In Australia, it is the Civil Aviation Safety Authority (CAS). No matter the country, many of the rules are similar. For example, most countries have a 120 meter (400 foot) above-ground limit for drones and a requirement to maintain visual line of sight (VLOS) of your drone while flying.
As an operator of an unmanned aerial system (UAS or drone), it is your duty to understand and comply with whatever rules exist where you fly. For example, in the USA and flying recreationally, you must register yourself with the FAA (if flying a drone weighing over 250 grams) and take the "TRUST" test. Obviously, there are more details and more to know than what is provided here. It is your responsibility to understand and follow the rules that govern UAS operations that pertain to you.
Airspace can be generally divided into two categories: controlled and uncontrolled. Controlled airspace is generally found around airports with control towers. Uncontrolled airspace is everywhere else. It is actually much more complicated than that, but this is a start.
As a UAS pilot, it is your responsibility to know what type of airspace you are flying in and to obtain authorization, if required. In the USA, LAANC (Low Altitude Authorization and Notification Capability) apps are available for mobile devices and make it very easy to check the airspace and obtain authorization (if required) prior to any flight. If the flight will occur in controlled airspace, and LAANC (USA-only) authorization is not available, it would be illegal to fly at that location.
DJI drones also employ geofencing. Depending upon the type of geo zone, you may receive only a warning (Yellow Warning Zone), you may need to check a checkbox acknowledging that you understand the dangers (Orange Enhanced Warning Zone), or you may be required to unlock the zone (Blue Authorization Zone). DJI geo zones may or may not line up with controlled airspace or LAANC (USA-only) grids.
Don't confuse geo zones with LAANC (USA-only). They are two different things. In the USA, LAANC is a mechanism by which one can gain authorization to fly in controlled airspace at a certain location for a certain period of time. Unlocking a geo zone simply enables a drone to fly within a geofenced area but does not authorize you to fly there.
While flying a drone, it is required to carry certain documents so that they are immediately available upon request by a law enforcement officer. There are other documents that are not required but can be very useful under the right circumstances. It is better to be prepared in the unlikely event that they are needed to assist in defending your rights. In the unlikely event you are approached and questioned by someone about the legality of your flight, it is better to have these documents readily available.
Your drone has a compass. Upon power-up, the compass is used to initialize the Inertial Measurement Unit (IMU) in your drone. If that initialization occurs while the compass is deflected by metal near the drone, once in the air, the drone may fly away in an uncontrollable spiral.
To make sure this does not happen, never power-on the drone and take off near metal. Avoid placing your drone on and taking off from concrete (may contain rebar), a vehicle, a metal table, etc. It is important to always verify that the drone icon on the map in the DJI (or Litchi) flying app is pointing the same direction as the actual drone. If it is not, power-off the drone. Move to a new location and power it on again.
Occasionally, the app may show a warning that compass calibration is needed. In most cases, this warning is incorrect. Instead of re-calibrating, power-off the drone and move to a new location and try again. Certain drones (Mavic 2 Pro/Zoom) force a mandatory compass calibration every few months or after the drone is moved a certain number of miles from the previous location. This forced calibration is unfortunate and was a mistake made by DJI and has caused a lot of confusion around compass calibration.
The compass calibration process is designed to eliminate any magnetic disturbance that may be attached to, or part of, the drone. It is only necessary to re-calibrate your compass when your drone has been changed in some way (adding or removing a device). It is not necessary to re-calibrate your compass when moving to new locations as it has nothing to do with location.
DJI drones use GPS for positioning. GPS (and sometimes, the vision system) is used to hold the drone's horizontal position while no stick inputs are given. On a windy day, the drone may tilt to hold its GPS position. When releasing the sticks after flying horizontally, the drone will "apply brakes" to hold its GPS position. Without GPS, the drone will have no "brakes" when the sticks are released. A good GPS signal requires an unobstructed view of the sky. Flying between buildings or mountains may reduce the drone's ability to have a good GPS lock.
It is important to ensure that the drone has a "GPS lock" before taking off. This is usually indicated by a green banner showing "GPS" at the top of the flying app. One may also hear the message: "The Home point has been updated (or set). Please check it on the map." This usually occurs once the drone has locked on to around 13 satellites. However, the number of satellites is not as important as their position in the sky. When the GPS algorithm in the drone is satisfied that it has access to a sufficient spread of satellites, it will let you know.
If you take-off prior to acquiring a GPS lock, your home point will not be set until some point after you take off. If one were to then use the RTH function, the drone would return to the point where it acquired a GPS lock (which could be in the middle of a lake) instead of the location the drone took-off. To avoid this scenario, always wait until there is a GPS lock before taking off.
Wind can be a drone's enemy. Larger drones may be able to withstand stronger winds than smaller drones. It is important to be familiar with your drone's ability to withstand winds. If you are unsure, perform some safe wind tests in an open field while keeping the drone relatively close to the ground. Only increase the height of the drone after verifying the drone's ability to navigate in the wind. Performing tests like this will give you more confidence when flying higher and further in the air.
It is also important to know that generally, winds are stronger the higher you fly. If your drone is having difficulty holding its position in the wind, lower your drone. If there is a choice, always fly away against the wind so that the drone's return trip back home is with the wind. Don't arbitrarily set your RTH height needlessly high. Doing so may expose the drone to higher winds that it can handle.
There are useful apps, such as "UAV Forecast" that will help to determine whether or not it is safe to fly in the current conditions.
Most DJI drones use Lithium-Ion Polymer (LiPo) batteries. LiPo batteries are stressed when they are either fully charged or low on charge. They are least stressed when around 50% charge. To extend the lifetime of your batteries, never leave them in a fully (or low) charged state for an extended period of time. The circuitry (BMS) in DJI batteries will enter "auto-discharge" mode after a certain number of days at a high charge, but the time at a high-charge should be kept to a minimum.
The best practice is to fully charge the battery just before a flight. If the battery is flown to a low level, after it cools, charge the battery back to around 50% if it will not be used again for a while. Never use a battery that has not been recently fully charged. A battery stored for a time with less than a full charge may have unbalanced cells. A low cell may unexpectedly fail sooner than expected. Monitor cell deviations using AirData.
It is also good practice to cycle a LiPo battery periodically. Do not let a LiPo battery sit unused for an extended period of time. After a few months, it would be a good idea to charge (and then discharge) the battery back to storage level. More details can be found in the link below.
Always store batteries at room-temperature. Never store them in a hot car. Do not fly with a cold (less than 16° C) battery. Keep them at room-temperature.
DJI drones have various Return-To-Home functions where the drone will automatically return to the home location when certain conditions are met. There are actually three different RTH modes:
Every DJI drone will initiate its Failsafe RTH procedure upon loss of signal. The procedure that the various models follow may differ slightly (consult the user manual). Generally, upon signal loss, the drone will ascend to the configured RTH height, then fly a straight path to the home point recorded at take-off.
As you are flying, if the software determines that you only have enough power to get home from its current location, the drone will initiate its Low Battery RTH procedure. This RTH mode should never be cancelled as the software has already determined you only have enough battery power to make it back to the home point.
This mode is used manually whenever you wish to automate the return of the drone. If you lose sight of your drone or if you simply want the convenience of a simple, autonomous return, you can press this button. A second press of the RTH button while already in RTH mode will cancel Smart RTH.
Anytime you make your first flight, whether you are new to drones or are using a flight mode that you have not previously used, your flight should be performed in an open outdoor area without any obstructions. Some choose to perform their initial flight indoors. Don't do this. GPS drones are designed to fly outdoors. There are too many things that can go wrong indoors (obstacles, no GPS, fatal RTH, etc.) that a new flyer may not realize.
Take the time to read the manual for your drone. Flying a drone is easy. Knowing every detail about how the drone will respond to various events is difficult.
It is a good idea to get into the habit of going through a safety checklist of items before each flight. The list of what one checks may differ from person to person. The following list are some things to consider having on your checklist.