By Elan Head

An award-winning journalist, Elan is also a commercial helicopter pilot and an FAA Gold Seal flight instructor with helicopter and instrument ratings. Follow her on Twitter @elanhead


Archer turns tables on Wisk in eVTOL patent fight

Accused of stealing its eVTOL design from Wisk Aero, defendant Archer Aviation has turned the tables on its rival, claiming that Wisk filed its patent application for the design only after Archer’s founders disclosed that design to Wisk’s chief engineer.

Archer Maker front
Wisk has accused Archer of stealing trade secrets and copying its design for the Maker eVTOL, which was unveiled in person this month. Archer Photo

Attorneys for Archer make the accusation in their opposition, filed June 24, to Wisk’s motion for preliminary injunction, which seeks to prohibit Archer from using or disclosing what Wisk claims are stolen trade secrets. The opposition describes Wisk’s request as “so ill-defined and overbroad that it effectively would shut down Archer’s aircraft development, with potentially catastrophic effects to Archer.”

Archer, which has an agreement to combine with the special purpose acquisition company Atlas Crest Investment Corp (NYSE: ACIC), stands to lose $1.1 billion in gross proceeds should that deal fail to close later this year.

Wisk has accused Archer not only of copying its design — submitted in a confidential application to the U.S. Patent and Trademark Office in January 2020 — but also of using proprietary information related to aircraft, component, and system designs to accelerate its eVTOL development efforts.

Archer emerged from stealth only last year and has the ambitious target of certifying a passenger aircraft by 2024. Wisk is a Boeing-Kitty Hawk joint venture that through its predecessor companies has been developing eVTOL aircraft since 2010, although it has declined to share a timeline for certification of its self-flying air taxis.

Wisk claims that “the development of an entirely new kind of passenger aircraft requires years of engineering and significant expertise to get right,” and that Archer’s aggressive timeline is “virtually impossible” for an originally designed aircraft. Wisk has lost at least 20 employees to Archer and contends that one of them, senior power electronics engineer Jing Xue, downloaded nearly 5,000 files from Wisk’s secure corporate Google Drive repository before his abrupt departure.

In its motion for preliminary injunction, Wisk says its internal forensics investigation determined that these “highly valuable files” contained trade secrets that span the gamut of systems used within the aircraft, as well as information that could be used in manufacturing — collectively representing “years and countless hours of research, development, and testing by hundreds of Wisk engineers.”

However, Archer claims it conducted its own digital forensics investigation looking for matches to these files on its own systems, and turned up nothing.

“There were zero hits among the 851 documents Wisk claims Xue downloaded and support Wisk’s trade secrets,” Archer’s opposition states (emphasis original). Archer said it also failed to find any “near duplicate” files in its systems, or matches on an image of Xue’s Archer laptop. Xue has denied under oath that he provided any Wisk documents or confidential information to anyone employed at Archer.

Wisk Archer eVTOL
Wisk released this comparison of its confidential eVTOL design and Archer’s Maker eVTOL when it filed its lawsuit against Archer in April. Wisk Image

As for the resemblance of Archer’s two-seat Maker technology demonstrator to the design in Wisk’s confidential patent application, Archer intimates that Wisk may have been the one doing the copying.

Archer claimed in court filings earlier this month that the Maker design was conceived by an independent firm, FlightHouse Engineering, in late 2019, before any Wisk employees joined Archer. Now, Archer contends that its founders, Brett Adcock and Adam Goldstein, revealed key details of that concept to Wisk senior engineer Geoff Long during a recruiting attempt on Dec. 9, 2019. Specifically, they told Long that they were planning to use a 12-rotor fixed-wing aircraft with two or six tilting rotors.

“A few days later, Long told Wisk’s CEO, Gary Gysin, and Wisk’s chief technology officer, Jim Tighe, about Archer’s plans, including its plans for a 12-rotor tilting design, and the fact that Archer was working with a third-party consultant,” Archer’s opposition states, pointing out that Wisk didn’t file its provisional patent application until Jan. 31, 2020.

“At an absolute minimum, Wisk’s use of the application created after Archer’s disclosure to Wisk to create the impression that the similarity cannot be a ‘coincidence,’ and that Archer must have stolen Wisk’s design, is deeply disingenuous,” the filing claims. “Whether or not Wisk took the designs in its application from Archer (and the consequences for that conduct) is for another day.”

A spokesperson for Wisk told “Archer’s latest filing is full of inaccuracies and attempts to distract from the serious and broad scope of misappropriation claims it faces. The filing changes nothing. We look forward to continuing our case in court to demonstrate Archer’s improper use of Wisk’s intellectual property.”

Maker design revelations

In the process of making a case against Wisk, Archer’s opposition and the supporting declaration of its chief engineer, Geoff Bower, reveal new details about the Maker aircraft and its third-party vendors.

Bower, who previously served as chief engineer for Airbus’s Vahana eVTOL project, says he selected FlightHouse’s “12-tilt-6” concept — with six tilting rotors — after conducting his own analysis of alternatives in early 2020.

As for the aircraft’s V-tail, similar to the one in Wisk’s design, Bower says in his declaration that he “anticipated little effect on performance in flight from using a V-tail, a Y-tail, or a T-tail” and did not have a strong opinion on which style to use. The V-tail was selected for aesthetic reasons by industrial designer Frank Stephenson, “and I understand that Brett [Adcock] and Adam [Goldstein] also liked the progressive, ‘cool’ look of the V-tail,” Bower says. “As a result, we elected to move forward with a V-tail without detailed technical discussion or detailed analysis about its expected performance, because it was a configuration that I had no doubts would work.”

Archer Maker eVTOL
Archer chief engineer Geoff Bower says that Maker’s V-tail and five-bladed proprotors were chosen primarily for aesthetic reasons by industrial designer Frank Stephenson. Wisk cited both in its original claim of patent infringement. Archer Photo

The five-bladed configuration of the aircraft’s proprotors was also selected by Stephenson for its aesthetic appeal, Bower says in a section of his declaration that is partially redacted. After aerodynamic modeling showed “minimal” performance differences between various configurations, “we sent the proprotor designs to Stephenson, he thought the five-bladed propeller looked great on our plane, and we decided to go with his recommendation,” Bower recounts.

According to Bower, Archer is procuring MAGiDRIVE integrated motor and motor controller combinations for its Maker aircraft from the third-party vendor MAGicALL, which supplied the same family of electric propulsion units (EPUs) to the Vahana program. MAGicALL keeps the core structure of its motors confidential even from its customers, which means “we do not know (and couldn’t disclose if we did) the details of the technology underlying the MAGiDRIVE motors used in the Maker prototype,” Bower says.

Meanwhile, Maker uses six independent lithium battery backs, each of which provides power to a unique pair of MAGiDRIVE EPUs on opposite ends of the aircraft. All of the battery packs and associated battery management systems were designed and manufactured by Electric Power Systems (EPS), which likewise does not share the core structure of its batteries with customers. The batteries are charged over a high-voltage bus using a charger from another third party, Electro-Aero.

Bower’s declaration also reveals that Archer is using low-voltage batteries from Lithios Energy, flight control computers from Curtiss-Wright Corporation, inertial navigation systems from Safran and another vendor, and air data computers from Aeroprobe.

Bower states that the eVTOL industry has “progressed significantly in recent years, such that the time necessary to design and manufacture an eVTOL aircraft has fallen dramatically.” According to Bower, published papers and industry conferences have made information about eVTOL flight widely available — a point also made by Georgia Tech professor Marilyn Smith, who has been retained by Archer as an expert witness. In a heavily redacted declaration filed earlier this month, Smith asserts that Wisk has failed to distinguish its alleged trade secrets from what is already publicly known.

Commenting on Archer’s projected timeline, Bower says Archer expects to conduct the first flight of Maker in December 2021, or 26 months after the company first engaged FlightHouse Engineering. That’s comparable, he remarks, to the 21 months that elapsed between Vahana’s early conceptual design stages and first flight.

As for Archer’s goal of certifying a larger, five-seat aircraft with the U.S. Federal Aviation Administration (FAA) by 2024, Bower describes it as “aggressive, but achievable if we hit all of our target goals on time.”

“The Maker will be an autonomous, pilotless aircraft. Our production aircraft will be piloted,” Bower states. “If we achieve FAA certification in 2024, we will all be very pleased. But if the process drags behind our target timeline, I will not be surprised, as FAA certification is not something that is completely in our hands.”

This story has been updated from its original version with expanded comment from Wisk.

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