Flight automation developer Merlin has built its own simulator as a test bench for the technology it is working to introduce on both civil and military aircraft. The company this week announced that it has started using the Certification System Bench for development work at its Boston headquarters.
According to Merlin, the simulator—built from certifiable software and hardware—allows it to keep testing its Merlin Pilot without interruptions during adverse weather conditions or when aircraft are grounded for maintenance. It features cameras that give the company’s distributed global team remote access for tests and also includes three screens representing the flight deck with accurate instrument panels and primary flight displays.
The company said it expects the initiative to accelerate the FAA supplemental type certification (STC) process to get the technology approved to be integrated with existing aircraft. Merlin’s plans already call for it to retrofit utility aircraft including Textron Aviation’s King Air 90 and Cessna Caravans, and the Twin Otter.
Under an agreement announced in February, Merlin is also working with the U.S. Air Force on plans to equip the KC-135 military transport and refueling platform with autonomous flight technology. Each aircraft will require its own STC to use the technology.
"Creating a Pilot, Just Not a Human One"
“Our plan is to be able to create a pilot, just not a human one,” explained Merlin CEO Matthew George. “At first, the Merlin Pilot will be used in the place of a second pilot [onboard the aircraft], but later it will be the only pilot.”
Effectively, the plan is for the Merlin Pilot to get its own type rating for each aircraft, just as a human pilot has to do. As it prepares to validate the safety of the system with regulators, the company has been conducting extensive flight trials in both Alaska and New Zealand.
“We want to expose Merlin Pilot to as many operating environments as we can, so that it can learn lessons ahead of certification,” George told AIN.
However, the new simulator, which has taken six months to design, will allow the company’s development team to more efficiently expand the scope of flight tests. According to George, it cost millions of dollars more than its test aircraft to develop the equipment but will deliver a return on the direct investment by accelerating the program, which launched in 2018.
“In many ways, the Certification System Bench acts as a testing ‘funnel.’ It allows us to test hundreds of cases with speed and ease, selecting edge cases to take to inflight testing,” explained chief engineer Sherif Ali. “With pilots on the Certification System Bench, we are able to learn multitudes about human factors while gaining accreditation towards our STC.”
At face value, the Merlin Pilot architecture looks like that of a traditional flight control system. It will be fed data from various sensors including a high-accuracy GPS, an inertial measurement unit, and radar or radio altimeters. CMC Electronics is developing its flight data computer, and this is now in the final stages of certification.
“To be certified, the system has to have no single point of failure so that if any part of it fails it still meets the highest standards of safety,” George explained. “We will get to this by starting with human-supervised autonomy. We have to think about all the human factors because we want humans to be engaged in the flight. It’s also about building trust and that means tens of thousands of flight test hours.”
Natural Language For Air Traffic Control
According to George, the challenges involved in proving the safety case for autonomous flight can’t all be solved by tweaking algorithms. Merlin is using other tools such as natural language to support the integrity of operations. “We’ll be there when the checklist ends,” George said, pointing to factors such as inflight emergencies and changes in routes forced by weather conditions as issues that have to be covered.
The integration of natural language processes involves training an artificial intelligence model from thousands of hours of tagged audio to “learn” how human pilots and air traffic controllers interact. Until controller-pilot data link communications can handle all aspects of air traffic management, Merlin is working on the assumption that the Merlin Pilot will have to be able to communicate with controllers, who will talk to the aircraft and receive a natural language response.
Merlin is one of several companies striving to deliver increasing degrees of autonomous control to existing aircraft. Along with Lockheed Martin, it is focused on an onboard autonomy approach that George said is harder and more time-consuming to certify.
“In another camp, you’ve got companies like Xwing, Reliable Robotics, and General Atomics who are doing next-generation remotely piloted systems, which make it easier for them to operate uncrewed flights,” he concluded. “But we think the human could prove to be kind of a limiting factor, kind of a crutch.”
Merlin’s primary objective now is to get the first aircraft-specific system ready for the FAA to assess and start certification flight testing. It is planning further collaborations with prospective aircraft operators and is already generating revenues from its work with the U.S. Department of Defense.
Last month, Merlin appointed former Palantir executive Soo Cho as its chief operating officer. Grant Crenfledt, the company's director of operational compliance and safety has been promoted to be CEO of its New Zealand subsidiary, and finance vice-president Patrick DePriest is now group CFO.