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Despite COVID-19, eVTOL Avionics Development Forges Ahead

Analysis of the latest technologies being developed by avionics OEMs for the emerging eVTOL market.

While the COVID-19 pandemic has put a crimp in aviation worldwide, avionics development for future electric vertical take-off and landing (eVTOL) applications has forged ahead.

“Most of our engineers are currently working from home, so the biggest change we've seen is with lab or integration efforts, or any time engineers must be physically present in a lab,” said Hector Garcia, Honeywell Aerospace’s senior director of engineering for urban air mobility/unmanned aircraft systems (UAM/UAS). “However, we quickly adapted to that change and have been able to proceed as planned.”

While Honeywell has announced collaborations with eVTOL manufacturers, Vertical Aerospace and Pipistrel, the company plans to announce new partnerships with eVTOL OEMs in the coming months.

Honeywell has developed autonomous, avionics flight technologies, such as the company’s lightweight IntuVue RDR-84K radar and the Compact-Fly-By-Wire System, which features “cable-less” avionics and which the company says can provide envelope limiting to control the aircraft safely if a pilot becomes disoriented.

A computer generated rendering of a prototype cockpit display Honeywell Aerospace is developing for the eVTOL market. Honeywell Aerospace

The RDR-84K radar provides multiple radar beams for simultaneous detection of weather, aircraft, ground vehicles, buildings, and people. Honeywell has also built lightweight actuators that may apply to UAM, such as the Variable Bleed Valve Actuator (VBVA)—a pneumatic, fuel-driven, or electromechanical actuator which adjusts the position of engine bleed valves, provides feedback to the engine’s controller and increases engine efficiency.

In addition, last September Honeywell unveiled its next-generation avionics lab at the company’s Deer Valley avionics plant in Phoenix, Arizona. The lab resembles a conceptual UAM vehicle flight deck—a pilot’s seat in front of a primary display and three large, wraparound displays to view the simulated environment outside the aircraft.

The lab “integrates the actual Fly-By-Wire Computer and Vehicle Management System, using real hardware and software — which makes the flying experience much closer to what a pilot would actually encounter in a real aircraft,” according to Garcia.

Rick Hearn, the product manager for safety-certifiable solutions for Curtiss-Wright Defense Solutions, believes that “the good news for commercial off-the-shelf [COTS] vendors is that the same size, weight, and power (SWaP)-optimized solutions they’ve been actively fielding in recent years to address various design assurance levels (DALs) of D0-254 safety-certifiable hardware requirements for manned and unmanned airborne platforms are also well-positioned to meet the needs of eVTOL vehicles.”

“For COTS vendors, the eVTOL market holds great potential, since these platforms will require a number of subsystems that can be addressed early on with existing safety-certifiable COTS products,” according to Hearn. “These autonomously piloted vehicles also will find use in military environments, as they can reduce the number of personnel at risk during flight while eliminating the significant noise of a helicopter’s rotating blades. The avionics requirements of these platforms provide a range of opportunities for system designers, including systems for flight control computer (FCC), automated mission management (AMM), detect and avoid (DAA), terrain awareness warning system (TAWS), CVR/FDR flight recorders, battery management, and propulsion.”

Hearn said that “COTS vendors already have reliable and proven MIL-class safety-certifiable solutions that UAM developers can use to start prototyping right away.”

Last September, Curtiss-Wright said that an unspecified eVTOL builder had awarded the company a contract to provide a rugged, ultra-small form factor (USFF) avionics system and networking solutions for use on the eVTOL OEM’s new fixed-wing aircraft, which is to be a piloted urban air taxi that uses Curtiss-Wright’s flight control computer and vehicle Ethernet switch solutions during flight testing. Curtiss-Wright said that it is providing the aircraft the company’s less than 1.5 pounds, fully rugged Parvus DuraCOR 311, a USFF embedded computer/controller based on a low-power quad-core Intel® Atom™ E3845 (Bay Trail-I) processor, and the half-pound Parvus DuraNET 20-11, a USFF 8-port Gigabit Ethernet (GbE) switch—both optimized for size, weight, power and cost (SWaP-C) constrained aircraft.

While cable-less avionics technologies help reduce weight for eVTOL, Florida-based Carlisle Interconnect Technologies (CarlisleIT) said that it offers coaxial cables for eVTOL avionics that provide weight savings.

“Of particular interest in the eVTOL space are our aerospace-grade coaxial cables and connectors,” Tom Turner, CarlisleIT’s product manager of power and grounding, wrote in an email to Avionics International. “I say this because the eVTOL market is very concerned about weight, and as an aerospace company, we have always put a lot of emphasis on weight savings. To keep coax cables light, one option we provide manufacturers is an ARACON® outer braid. ARACON is a metal-clad fiber with a weight savings of up to 80 percent versus what you get with conventional metal braiding. When combined with the ultra-low-density PTFE dielectric of CarlisleIT’s UTiFLEX® cable assemblies, you’re left with a very light aerospace-grade product with superior performance.”

CarlisleIT said that it examines interconnect systems across its portfolio to reduce weight—a key consideration for eVTOL OEMs—while ensuring that the systems are ruggedized for the aerospace environment.

“For instance, the trays that hold the LRUs [line replaceable units] must meet stringent qualification requirements of documents like ARINC 404A or 600 and RTCA/DO-160.,” according to Turner. “At CarlisleIT, we accomplish this while saving 20% of a standard tray’s weight.”

In addition to lightweight, rugged hardware required for eVTOL aircraft, the latter also need high bandwidth in small spaces—a demand filled by CarlisleIT’s Octax® family of data connectors which deliver up to 10 Gigabits per second (GBPS)—10 times the transmission speed and twice the density of standard Quadrax-type solutions, the company said.

“Octax connectors can be combined with CarlisleIT 10 GB Ethernet cables, which are both lightweight and compact in size,” per Turner. “These cables are finding applications in backbone, high-definition video, and avionics systems today. However, with all of the power being transmitted in these electric or hybrid-electric aircraft if electromagnetic interference (EMI) becomes a concern, CarlisleIT has a range of fiber optic cables and interconnects. Fiber is smaller and lighter than copper, resulting in added benefits for applications where size and weight are the primary concerns.”

Last May, Germany-based Diehl Aviation and Volocopter announced that Diehl’s Diehl Aerospace unit would provide the flight control computer system (FCCS) for VoloCity—what Volocopter has said will be the first fully electric air taxi available globally. Diehl said that its contract with Volocopter represented its first foray into the eVTOL market.

At the time, Diehl said that it expected certification of the FCCS in 2021 and VoloCity’s first flight and entry-into-service within two to four years.

Diehl is also looking into other eVTOL opportunities.

“Diehl is addressing the emerging markets for UAM/eVTOL, which promise a significant potential,” David Voskuhl, a spokesman for Diehl Aviation, wrote in an email. “Already now, Diehl is contracted to develop and manufacture avionics components, based on existing in-house technology that had been applied on civil aircraft for decades. Just the same, the company intends to seek opportunities to supply further products to UAM/eVTOL customers, which are on offer for manufacturers of civil airliners already. Beyond avionics, that could be cabin interior and lighting solutions as well as environment control systems, industrial design services, and electrical components. In principle, any OEM in the UAM/eVTOL market segments is a potential customer.”