The Future of Advanced Air Mobility

In a Phoenix Laboratory, Honeywell Is Putting Leading-edge Advanced Air Mobility Technology to the Test

Honeywell Aerospace plans to enlarge its urban air mobility laboratory later this year as it steps up collaborative work, now at various stages, with more than a dozen companies in the sector. Stephane Fymat, vice president and general manager of the U.S. group’s Urban Air Mobility and Unmanned Aerial Systems business unit, told a media briefing last week that the facility in Phoenix, Arizona, will be made four times larger to allow for the installation of more test equipment, including hardware-in-the-loop flight simulators.

“To make it a reality...where you have ubiquitous eVTOL air taxi services flying over traffic and small drones delivering medical supplies and food, there are various enabling technologies that have to be researched, tested, and brought to market, and that is where Honeywell is focused,” Fymat told reporters.

One key issue being addressed by the Honeywell team is the challenge of training the large numbers of pilots that are expected to be needed as air taxi networks scale up. Their response to this is to simplify eVTOL flight decks, reducing the need for extensive recurrent training.

During a virtual tour of the laboratory, chief technology officer Hector Garcia showed how the company is developing distributed processing modules for the avionics with an open architecture that allows for changes based on the complexity of the vehicle on which they will be deployed to manage the new types of flight controls. The Honeywell engineering team is also working on complex algorithms for fly-by-wire systems.

The demonstration included a simulator being run by a flight-control computer based on the company’s scalable distributed processing model for which the hardware is significantly smaller and lighter than for existing aircraft. The flight plan was loaded into the simulator and when the pilot deviated from it the fly-by-wire controller prevented the aircraft from getting into any unsafe attitude. When he released the inceptor control stick, the aircraft returned to the flight path.

Garcia explained that the laboratory simulation is intended to replicate what eVTOL aircraft developers need for the avionics onboard. It allows Honeywell engineers to work with their partners to integrate flight deck systems and conduct troubleshooting exercises.

The pilot conducting the demonstration in the simulator is an experienced UAV operator but does not have a pilot’s license. The simplified vehicle operation demonstrated in the simulator shows how eVTOL aircraft pilots could be trained in just a week or two, Garcia said.

According to him, eVTOL aircraft with their complex array of propulsors (e.g.. fan blades, rotors) would be “unstable” without the control provided by the flight computer and the fly-by-wire control laws. As an example of how Honeywell—which produces avionics for much larger airliners and business jets—has been able to scale down the size and weight of the hardware, Garcia pointed to the inceptor units in the simulator. The company is also working on a simplified user interface for the flight decks of eVTOL aircraft.

Honeywell showed a ground testbed for its RDR84K digitally active phased-array radar for drones. The detect-and-avoid unit is about the size and weight of a hardback book (under two pounds), and it can see other small aircraft and drones up to two miles away in any conditions to support beyond-visual-line-of-sight operations.

Garcia explained that the RDR84K, which runs on 60 watts of power, can be steered to point in any direction. When pointed down to the ground, it can act as a radar altimeter and also track terrain to compare it with Honeywell’s moving map database. This provides backup in environments where GPS service is not available.

Honeywell is also focusing its efforts on plans to expand the endurance and range of small drones to between 60 and 90 minutes and up to 750 miles. Working with BFD Drone Technologies, it has developed a prototype using hydrogen fuel cells that can be recharged in just 10 minutes.

Fymat described the wider advanced air mobility sector as “a very big opportunity and very disruptive to the [aviation] market.” He said that Honeywell is working with more than a dozen companies, including aircraft developers. It has publicly acknowledged only two of these partnerships, which involve UK-based eVTOL aircraft developer Vertical Aerospace and Slovenian electric aircraft manufacturer Pipistrel, which is developing unmanned cargo aircraft and a sub-regional passenger aircraft called the Miniliner.