After thinking about it for so long, I finally bit the bullet. I knew I could do drone piloting without needing the A2 Certificate of Competency (A2 CofC), but had no general grasp on what I actually needed to know about drone aviation. Even though this area of technology and aviation really interests me it was still unclear on what was legal and illegal to do with them due to the changing UK legislation, and I’m very glad to say that the A2 CofC has really cleared that confusion away and is giving the enthusiasm to become a drone pilot. However it doesn’t only teach you about drone piloting, it teaches you about a whole new and developing frontier of aviation.
As such I would like to introduce my new series of articles, which will provide a snapshot summary into the areas covered in the various A2 CofC modules in the hope to provide a good outlook on what the course is and why it is beneficial. The series starts off with a bumper article that covers vital parts of Air Law, Meteorology and UAS Flight Performance.
Get the UAVhub A2 CofC course here: https://www.uavhub.com/pages/a2-qualification
Air Law
Luckily the A2 CofC starts off by explaining the most obvious things you will need to know about, more so it does a good job at giving the information to you in bite sized chunks. However there is still a good amount of terminology, regulation and legislation for you to wrap your head around when and if you take the course that prepare you for now and for the future.
Vital Terminology and concepts
Terminology in the course actually applies to all aviation in the UK and certain aspects and situations you’ll need to consider. For example various terminology exists to differentiate the different aircraft drones, such as Unmanned Aerial Vehicle (UAV), Unmanned Aircraft (UA) or Small Unmanned Aircraft (SUA) and for vital documents such as the CAP 393 and CAP722; also known as the Air Navigation Order and the general guide to operating within the regulations. While the different ways for saying drone may not be important to you as a drone pilot, the CAP 393 is essential to understand as it is responsible for all regulating all types of aircraft in the UK and also feeds into other concepts that you’ll need to understand.
The main rule of thumb in the CAP 393 to follow is Article 241, which states that 'A person must not recklessly or negligently cause or permit an aircraft to endanger any person or property’, so what are the main concepts you need to understand in accordance to this? Assemblies of People is your primary concern when considering article 241 in your operation plans. In principle, the concept first and foremost thinks of health and safety, and the possibility of whether a person can move out of the way of an awol UA without injury. With this principle, the Civil Aviation Authority (CAA) determine the appropriate separation distance of drones operating in certain flying categories (more on that later) which in turn affects where we could and could not operate. While these cases need to be assessed on a case by case basis, the general things to consider are the implications of Article 241, the potential disruption to the area, the potential of an accident and why or whether you think it will be appropriate to fly in said location (i.e.to fly over crowds at sports events, the probability of injury is high as is the probability of disruption, BUT while it may be too potentially dangerous fly in a commercial street during normal hours, it could be appropriate and safe when shops are closed so the streets will have less traffic). In a sense therefore, the idea of Assemblies of People is your primary concern when planning an operation.
However, can those people become involved people, or can you make sure that they can get out of the way and at a safe distance? We then dive into the concept of involved or uninvolved persons. To put it simply, an uninvolved person is a person who is A. not aware B. not involved and C. not interested. If we consider a crowd of any size for example, then it is automatically categorised as assembly of people and uninvolved persons, but an INDIVIDUAL person may become involved when they have given explicit consent to the UAS operator or to the remote pilot to be part of the UAS operation; and have received from the UAS operator, or from the remote pilot, clear instructions and safety precautions to follow in the case of a potential accident. Why is this important? it can not only effect our legality, should we ever need to defend it, but if people are involved you can shorten the separation distance to them locally, but to gain legality first and foremost you will need to ask them and brief then on health and safety protocols to keep them and yourself safe.
Categories: Drone and flying categories
MTOM (Maximum Take Off Mass) and Flying weight are the main ideas to understand when we talk about drone flying categories and aircraft sub-categories. MTOM for instance is the hypothetical maximum amount of weight an aircraft can carry while flying safely, while flying weight refers to the weight of the aircraft when it takes off and lands. MTOM in particular is a new term that will become important especially in the new wave of drones, as manufacturers will be legally required to declare an MTOM figure; and the reason for that becomes more clear as you dive into flying categories and certified aircraft classes.
The A2 CofC will only qualify you to fly in the Open category, where Operations present a low or no risk to third parties. While you could theoretically fly in this state without an A2 CofC, the qualification allows to operate in the upper sub categories in this class. As a general grouping though a drone’s MTOM must be less than 25KG, flown no less than 400m above the ground and must also be flown with unaided Visual Line of Sight (VLOS) at all times in this category. The sub categories are decided by MTOM and flying weight at the moment, and depending on whether you have a legacy drone or certified aircraft the sub category you fly will also be decided by other drone specifications that will come into effect during the current transitional period. In this respect the A2 CofC is also trying to prepare learners for a new standard of drone that will be safe to fly, but also warns that ‘Legacy drones’, like the Mavic 2 pro and Mini from DJI, will soon be categorised in different sections of flying categories as they are not built to those new standards. In the meantime the essential thing to understand about drone flying is MTOM and flying weight.
For an example lets take a DJI Mini 2 drone at its naked flying weight, as the commercial marketing of the product revolved around it being 249 grams. This is significant because the A1 category includes drones underneath the weight limit of 250 grams, meaning the drone can classify as a toy and can therefore be flown in gardens and over uninvolved persons.
However if we add accessories onto said drone, the weight obviously increases and this we are in the A2 category which means we cannot fly in gardens and have to consider the concepts mentioned earlier.
Collision Avoidance
Simple things to understand about collision avoidance is that the requirements for avoiding collisions are exactly the same as those for manned aircraft, meaning you do not hit civilians, vessels of any kind or any kind of structure. Moreover, it is legally necessary in the open category for you keep an unaided VLOS so you rely on seeing the aircraft in the sky, rather than seeing what is seen on the camera feed. In ideal conditions, an A2 drone can only fly 400m above the surface at all times but must be judged by the weather, VLOS and by the specifications of the drone. This is all done for the sake of collision avoidance, luckily the course covers incident reporting, insurance and the aforementioned CAP 722 much better than I could hope to here.
Meteorology
The first thing to know about the weather is how to use it to measure if it is safe to fly. Of course we can learn about Air Law, and later about Drone and flight performance, to assess what we can control but we can ultimately be a victim of the weather as well.
Weather apps
Weather is particularly important for the welfare of the drone and of the pilot, as for instance the drone may be fine in cold weather, but YOU may not be able to normally operate it; while on the other side of the coin your drone or drone equipment might start to suffer and lose performance in hot weather, even though you may be fully capable of operating. Therefore, we need to be aware of what is going on around us and the space we are operating in. On the whole you can use largely normal means of tracking the weather, but is most advisable to use very accurate websites such as the Met Office and BBC Weather; more so though the UAVforecast app gives specific UAV advice on whether you can fly in the sort of weather it shows you.
Clouds, fog and wind
While covering weather fronts is part of the A2 CofC course, and for the right reasons, covering it here again will not do it justice. Cloud, fog and wind are essential to understand as well however.
Clouds will have the biggest impact on drone operations, as they carry precipitation which can seriously hurt drones but you should not be worried about every cloud you see in the sky because they are still useful for you to predict any forthcoming bad weather. As seen in the diagram, there are three height groups of cloud. High clouds, as observed, are very wispy and will not present an immediate weather worry; however high clouds will develop into medium and lower clouds as they pick up precipitation. This therefore means that high level clouds can sometimes project the weather 7-8 hours in advance, while medium level clouds can indicate weather changes in a 1-2 hour window and means that low level clouds present an imminent risk to your operation. One cloud to always avoid though is the Cumulombinus cloud (Cb), by at least 10 miles due to the precipitation they may have, the GPS interference they can cause and due to the reduced visibility they bring.
Fog is also a necessary thing to worry about, and in fact it can be a desired setting if you are doing commercial. You do need to be safe though, so the effects of fog and how they affect an open category pilot is good to know. An obvious effects of fog is reduced visibility, but moisture accumulation and Cold weather can threaten the welfare of your aircraft as well. Moisture for example can effect electrical components while any cold weather between 4c- -10c can cause icing on the propellers which can affect performance and balance; therefore its advisable to take small test flights in the conditions to check for it before carrying out a full operation. On the other hand, the threats of wind to an aircraft can be much more dynamic. In this sense, turbulence and urban effects can easily effect the flight of a UAS but again I’ll leave that to the course to explain further.
Precipitation
Precipitation and the IP43 rating go hand in hand, but there is a reason that the IP43 is not a stamp that guarantees a waterproof drone. To be truthful no drone is invulnerable to rain, sleet, snow, hail or anything else that might fall out of the clouds. It is no surprise that the general advice about precipitation is that you should not fly in precipitation in any form or in any situation as most drones are not designed to fly in those conditions. Even those that take that in mind, the IP43 rated drones, are only designed to be water RESISTANT (NOT WATERPROOF) meaning they are useful for making sure that the aircraft can safely land should it get caught out in such bad weather but not for a sustained flight in precipitation conditions.
UAS Flight performance
Flight performance of various UAS is dependent on what form of aircraft they are, their specifications and their use of power. While not as relevant to what you might want to learn about, fixed wing aircraft flying also counts in the overall aircraft regulations.
Multi rotor aircraft and Fixed wing control
It is however an area of aviation worth learning about in this course due to how it helps us understand the different approaches the aircraft have. A fixed wing aircraft for instance controls its pitch with the elevator, whereas a multi-rotor aircraft uses a balance of power that favour the back motors, while the yaw of a fixed wing is rudder controlled a multi-rotor controls yaw through a diagonal pair of motors spinning in opposite direction to the other pair; more so the fixed wing aircrafts maintain their using the Ailerons on either wing, but a multi rotor uses the left and right pairs of motors to control their roll axis.
More so, MTOM and flying weight will also affect performance across both aircraft types as well as affecting the flight category you will be able to operate in. While you have to be concerned about that factor too in performance, centre of gravity is also a limitation as well that goes hand in hand. Even so, centre of gravity is a bigger concern with fixed wing aircraft due to their nature, whereas the payloads and accessories that you put on multi-rotor aircraft will not affect its flight as much (it is also worth noting that all future drones will have to disclaim the drone’s Centre of gravity measurement as well).
Flight Procedures
To help your personal performance as a pilot, flight procedures are also useful for you to have. With flight reference cards for example, you have a checklist of things you need to check before a flight such as batteries, memory cards and drone accessories but you also have the chance to think of dangerous scenarios and chart on these cards the procedures you will take to make sure they do not happen and how you will react if they happen.
Maintenance
Drone maintenance will be detailed in the manufacturer notes, but it does not mean that you should leave it until those times to care for your products. As drone flying is unpredictable, expensive and of danger to the public in extreme circumstances, it is vital that you check you drone every flight for damage to the propellers, damage to the body and for damage to the drone lens. You should be looking for whether the propellers are chipped (therefore you need to replace that), if there is any damage to the drone body that could compromise its flight (i.e. scratches, chips, loose mounts or screws) and for whether the drone lens has picked up anything that could compromise its vision. These ‘safe to flown’ assessment will be essential for ensuring your drone has a long life.
Batteries
Finally, batteries are also a big factor in UAS Flight Performance. While the A2 CofC goes into extensive details about the different types of batteries that apply to different drones, it is important to know about how to store Lithium Polymer batteries safely, how to charge them for durability and how to use them on operations. Short termmed as LiPo batteries, it is essential to store them away in places that do not pose a risk of fire as they discharge their power in order to be stable. When they are used in operations stay to the 80% rule (as batteries below 20% will be unstable and will damage the battery cells), monitor batteries for swelling all the time and come up with a system that makes sure that your batteries get AVERAGE use.
As detailed through, the course covers these issues in much more necessary detail than what I have described. As a course I fully recommend it as it is an interesting but more so is an essential into drone aviation and commercial drone aviation. Join me on my next entry where I’ll cover two modules in a similar fashion.
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