Safe & Reliable Operations

It’s a valuable combination to be both an aircraft manufacturer and an operator, as this helps us to think of safety from all angles. Operations are taken seriously at Avy, we use ISO 9001 and AS 9100 as the inspiration for quality management and standard procedures.

Avy is a certified operator and therefore has an ROC, the required operator certificate for any company that wants to fly a drone commercially. Our professionally trained pilots have an RPA-L (Remotely Piloted Aircraft License), the required license to fly a drone in a commercial environment and are trained in RT (Radio Telephony) to communicate with Air Traffic Control. As discussed in our first Safety Series edition, the SORA (Specific Operations Risk Assessment, the regulatory framework established by the EASA (European Aviation Safety Agency) is what guides us to safely create, evaluate and conduct our operations at Avy. 

Rule to Risk Approach

As a future with delivery drones becomes apparent, it becomes evident that drones will integrate into non-segregated airspace. The switch to a risk based approach was a great leap towards trusting drone operators to conduct safe operations after undergoing intensive testing and analysis.

To use drones for commercial purposes in the EU, the operator must have assessed the risks of a mission and undergone numerous technical and operational checks predefined by SORA for different types of operations (open, specific or certified). As addressed in Part 1 of the Safety Series, the SORA takes into account the following factors to ensure to a certain level of confidence that the operation can be safely conducted: 

• Ground risk: takes into account operational scenarios like flying over controlled ground, sparsely populated or populated areas and what is onboard the aircraft
• Air risk: determines risks to the surrounding airspace users 
• Operational Safety Objectives (OSO): the required safety objectives for a given operation

The ground and air risks as well as operational safety objectives evaluated previously will output a Specific Assurance and Integrity Level (SAIL). The SAIL determines the level of robustness required for the operational safety objectives (OSO) and represents the level of confidence that the drone operation will remain under control. Any given risk mitigation or OSO can be demonstrated at different levels of robustness (Low-High). Robustness is achieved through calculating the level of integrity (safety gained for each objective) provided by each mitigation and level of assurance (method of proof) that the claimed safety gained has been achieved. These are both risk based, for example, if the operator demonstrates a medium level of integrity with a low level of assurance, the overall robustness will be considered low.

Once technical and operational mitigations have been secured, the aircraft has proven to be high in robustness and is safe for operations. We interviewed Dinesh and Kitso, our senior pilots, to dive into the risk assessment conducted by flight operations. We rounded up some examples to demonstrate Avy’s safety checks and systems for its operations and may have slipped in a few hiccups that we’ve learned from to improve the safety for our team and ensure reliability for all our flights. 

Pre-flight safety checks 

To ensure safety for all operations, a correct flight preparation is a must. Once on the field, a 10min pre-flight check is conducted by the pilot and co-pilot that are operating the mission. This includes: 

• Assembling the drone and checking the software 
• Checking ground and air risks 
• Co-Pilot checks visually for unintentional proximity to any risks including other aircraft 

In-flight safety systems

• ADS-B transponder: transmits accurate positional information to ground controllers and picks up signals from other aircraft. Essential for collision avoidance and will be made even more reliable once the Iris Automation’s detect & avoid systems has been fully integrated
• Quadchute: if fixed-wing mode fails (e.g. loss of altitude), multicopter mode takes over and brings the aircraft to a steady hovering position
• Return To Launch (RTL): the RTL can be triggered automatically and manually, to navigate the aircraft back to home position
• Go To Rally Point (GTRP): the aircraft flies to the nearest designated safe landing zone
• FPV cam: if GPS is lost, control of the drone is done manually using FPV (First Person View) camera and a low latency link (LTE) to maintain control of the aircraft at all times
• Navigation and strobe lights: also known as anti-collision lights (green red and white) are integrated in the aircraft to improve visibility during flight ‍
• Modify mission during flight: Mission planning is done before the flight and can be adapted to the mission during the flight according to the operation

• Safe testing areas. We choose certain areas to do test flights in which we have (better) control over the ground and air risk. For example, we perform test flights at Valkenburg where the ground area is closed off and restricted to drone pilots. The airspace is an ATZ (Aerodrome Traffic Zone), which means that other airspace users are requested to avoid the area (since they know it’s an airport with expected higher airspace activity). 
• Keeping a safe distance. When we take off we do not climb to high altitudes overhead, but first move the aircraft away from the people on the ground (the ground crew) and then start climbing. If anything goes wrong during the multicopter phase, the aircraft drops more or less vertically and that will be at some distance from the ground crew.
• Lowering flight risks. We have a couple of mini vtols (mini versions of Avy Aera) that are used for experimental firmware, hardware or procedures. Once we’ve verified that it works with the mini vtol we can bring it to Avy Aera. The benefit is that the mini vtol is smaller and therefore will have a smaller impact if something goes wrong. So when we have an increased flight risk, we lower it by changing the aircraft to a testing one.

To guarantee safety, we’d be lying if we said there weren’t any hiccups along the way for Avy. Building and operating an aircraft isn’t easy, and since the technology is new, no day is the same. We’re continuously learning and improving our way of doing things to ensure that we’re the safest and most reliable operator.

F*ck ups that we learned from

• Guarantee safety for Flight Ops team at all times. Ensuring that our flight operations team is safe at all times, doesn’t rule out the testing zone at our HQ. Early on when the testing zone was still being arranged, we’d been meaning to get a net. During testing, the aircraft began to bounce about in hover mode. No harm was done, but from that moment on, a net was placed to protect anyone in its surroundings. 
• Importance of keeping track of the type of firmware on each aircraft. At some point we left an experimental firmware on an aircraft we also use for other flights. A critical bug was found in the firmware that could have been prevented. No harm or damage was done during that flight, but lessons were learned and checking firmware is now part of the pre-flight checklist. 
• Ensuring that GoPro battery is fully charged. All test flights are recorded for all landing and taking off, but this one time we forgot to check the battery life. Unfortunately, something happened during landing and because of the low battery, we were not able to record the test flight incident.  

Bridging manned and unmanned aviation 

Just like a plane, when drones fly BVLOS they must be visible to Air Traffic Control at all times. It becomes critical to enable drones to safely share the airspace with traditional manned aircraft while maintaining constant communication. The air traffic management under development for autonomously controlled operations of drones, is known as unmanned aircraft system traffic management (UTM). This is made possible thanks to different suppliers like AirMap, Altitude Angels and Unifly. 

Constant communication between the aircraft and these solutions such as transmission of signals is vital for a safe and reliable mission. Communication is another critical factor to ensure that our operations are done safely. These systems have been made redundant, meaning that they have their own fallback system. In the Avy Aera a number of different links are available for command, control and video streaming. A combination of LTE and Satcom gives the user a high bandwidth, LTE with a range independent backup (iridium satellite). 

An additional layer of safety for the Avy fleet is its reliable software powered by Auterion. The Avy Aera has a complete integration with the Auterion software platform and its operating system to ensure flight, safety and compliance management.

• Auterion Mission Control: The ground station software allows operators to make pre-flight checklists personalised to every airframe. It has a live video stream for BVLOS operations, which allows first person view (FPV) of the drone and adds a level of security to the operator. It also allows pilots to log into their personal account for compliance.
• Auterion Enterprise PX4: The flight control stack creates highly detailed and high-frequency flight logs which include data about the functionality of every system on the drone (e.g. vibrations of motors, load of CPU, temperature of CPU) so that we can have a deep understanding of the health of the system. It also supports computer vision for autonomous safety features like obstacle detection, collision prevention, or safe landing.‍
• Auterion Suite: Autonomous upload of flight logs to Auterion Suite in real time during the flight with 4G LTE. Flight logs are then analysed in Auterion Suite using machine learning algorithms that are trained for each vehicle model. This allows Avy to automatically monitor the health of each drone and flag issues before they become real problems (predictive maintenance). This automatic approach scales to any number of aircraft helping Avy scale safety to large fleets of drones.

Amongst other things, the latest addition to the Avy Aera is the upcoming integration with Skynode. Skynode is the latest autopilot based on the FMUv5X flight control standard and has triple redundant sensors on the IMU to increase the reliability of the systems.

With our mission of doing good, we want to be able to operate in urban areas helping day and night - whether it's delivering urgent medical goods or helping a fire brigade with making real-time decisions. A high SAIL level is required for this and that's our goal.

We don’t claim to know everything and have learned a lot from our collaborations with renowned parties such as the ANWB MAA, the Dutch operator of helicopters for emergency services. With more than 30 years of experience, the ANWB MAA operates around 8,000 flights a year for medical purposes. This partnership has helped Avy understand the complexities that come with managing a fleet of aircraft, the risks that come with this and a reputation to uphold. This has really helped us to achieve a higher level of safety and reliability when designing and operating our aircraft. 

Don’t miss out on the next and last edition of the Safety Series, focused on data protection and management! We’ve said it before, public perception is everything when it comes to integrating commercial (medical) delivery drones into non-segregated airspace, and with that comes the responsibility of being fully transparent. Drones can be seen as invasive and for that reason, we’ll explore the way data is handled at Avy and how information is gathered during operations in compliance with the GDPR standards.

Sources

EASA - Regulations