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November 3, 2021 | Our Approach to Safety

Safety is not stagnant. There is a certain impetus invoked by it, breeding a sense of security to move forward. Security to step beyond mere vision, to conquer new frontiers. As Archer’s aerospace engineers venture further into the electrical vertical takeoff and landing (eVTOL) aircraft frontier with more test flights of our Maker demonstrator aircraft, we remain focused on building an aircraft that is safe. Safety is not just a top priority of the FAA as they work with us on the certification of our eVTOL aircraft, but in the minds of future travelers and observers alike. As we venture forward together, our dedication to safety is paramount in our quest to commercialize urban air mobility (UAM) as an alternative to other current modes of urban transportation.

Safely Moving Forward

Safety results from taking responsibility, not simply theorizing, but acting. At Archer, building to requirements is not enough. Though we applaud and respect the difficult work done by the FAA and other regulatory agencies around the world in setting safety requirements, we choose to aim higher. Our teams are encouraged to consider safety in every decision, whether there are regulations that require it or not.

We are constantly working towards a better understanding of every aspect of the aircraft we are developing and actively considering not only what has happened, but what could happen; the hard-learned lessons from conventional airplanes and helicopters may not be enough to ensure safety moving forward.

We are committed to always aiming for safety as good as it can be, before ever taking to the skies. This is especially true for the three most innovative areas in our eVTOL aircraft design: propulsion, power, and fly-by-wire flight controls. Here’s how we’re working in each of these areas to ensure our eVTOL aircraft is one of the safest options for travel.

Propulsion

All commercial airliners have two or more engines and are designed to continue to fly safely if one of them shuts down at any point of the flight. They are also designed to remain controllable even if all engines shut down, though in that case they can only go as far as they can glide. Most helicopters, on the other hand, have only one main rotor - and the ones that have two need both to fly safely. A helicopter’s main rotors are very complex machinery, and if any individual component of that machinery breaks it could result in loss of control. This is one of the reasons why commercial airliners are inherently safer than helicopters.

Our Maker aircraft has twelve electric engines, six on each wing. Like airliners, it is designed to safely complete a flight if any engine shuts down at any point of the flight - including hovering. Unlike helicopters, Maker can continue to fly safely after any single part of its propulsion system stops working.

Power

Helicopter and airplane engines currently run on fossil fuels, like aviation gasoline or kerosene jet fuel. Airliners have separate fuel tanks and separate fuel delivery systems for each engine, attempting to avoid any single failure causing loss of fuel to multiple engines. However, there still exist numerous safety hazards with fuel delivery. Foreign objects forgotten inside fuel tanks during maintenance, extremely cold temperatures causing fuel not to flow properly, and other such issues have also caused multiple-engine shutdowns on airliners. 

Our Maker aircraft does not use fuel or combustion engines to power the aircraft, but instead uses six battery packs.  Not only does this electric power source result in our aircraft producing zero-emissions during use, it means that our power source has no moving parts and is fully self-contained (i.e., it uses electric energy stored in the batteries). This eliminates numerous potential hazards.

Maker is also designed to continue to fly even if a battery pack fails. It’s outfitted with six independent battery packs, each powering a set of forward and aft motors diagonally opposite each other. This means the aircraft can safely complete the flight even with total loss of power from any one of the battery packs. 

Fly-By-Wire Flight Controls

Traditional airplanes all the way back to the Wright Flyer have used mechanical systems to transform the pilot’s movement of the controls at their seat into movement of parts of the wing and tail, known as control surfaces. Air pressure on the control surfaces causes the airplane to change direction. Many features were added to flight control systems as airplanes became larger and more modern, including using hydraulic power and electric motors that made features like autopilot possible.

Over the last three decades, commercial airliner designs have transitioned to fly-by-wire flight control systems. These systems replace the rods, cables, and pulleys that were used to connect the pilot’s controls to the control surfaces with sensors, wires, and computers. Sensors in the pilot controls detect the pilot’s movements and transmit electrical signals to the flight control computers. These computers use a lot of additional information collected by other sensors on the aircraft to calculate the best way to move the control surfaces and perform what the pilot has commanded. Electrical signals from the flight control computers go to electric or hydraulic actuators, which in turn move the control surfaces.

Fly-by-wire systems can improve safety in many ways. They eliminate many moving parts that can jam or break, they allow each part of the system to be self-tested before flights, and they can be designed to continue to operate effectively even with multiple failures. It is very hard to fit more than two separate cable and pulley systems in an airplane for redundancy, while fly-by-wire systems can be triple or quadruple redundant. The advanced logic in the flight control computers can also react to things like wind gusts and propulsion failures much quicker than the human pilot, making for a smoother and safer ride.

Archer is always looking to incorporate the latest advancements in fly-by-wire technology into our aircraft to draw on its safety benefits, but also to accommodate the unique elements of our eVTOL aircraft. Beyond the traditional control surfaces, our aircraft has tilting propellers and can run all twelve engines at different speeds to control flight. The fly-by-wire system will seamlessly incorporate these elements so our pilots can handle the aircraft using simple control devices.

As with our propulsion and power systems, our fly-by-wire system will be designed such that it allows the flight to be safely completed after any single failure occurs, at any point of the flight.          

Team

Embarking on this new frontier is no simple feat. It will take the brightest minds and the most advanced technology, and we are ready. Between traditional aerospace and the newer eVTOL sector, Archer’s team brings more than 1,200 years of combined industry experience to the table. We’re on a mission not just to revolutionize the way people travel, but to ensure a new level of safety for our industry. It’s through our dedication to that mission and prioritization of safety that leads our team in every aspect of our design. We look to prove this not just in our first test flights with Maker, but every time we take to the air. Archer isn’t just building eVTOL aircraft; we’re helping build a cleaner, more efficient future, and we can’t wait to welcome you aboard.