Vertical dismisses Archer patent claims as ‘threadbare allegations’ in court filing

UK eVTOL developer says US rival’s argument is “self-defeating” as it asks for case to be thrown out.

Vertical Aerospace has asked a US court to dismiss the US patent infringement lawsuit filed against it by Archer Aviation, branding its rival’s claims as “threadbare allegations”.

Filed to the US District Court for the Eastern District of Texas on 1 May, the motion is Vertical’s response to the legal action that kicked off in late February.

Archer alleges that Vertical’s developmental Valo electric vertical take-off and landing (eVTOL) aircraft infringes three of its patents – two related to the design of its Midnight aircraft and one to its flight-control system.

UK-headquartered Vertical unveiled the Valo in December last year, having been flight testing its VX4 aircraft since September 2022.

Prior to the Valo’s arrival, the VX4 had been presented as the aircraft Vertical intended to bring to market, having amassed around 1,500 conditional orders for the platform.

While the Valo leans heavily on the test data amassed by the VX4 – and retains the same propulsion architecture and other features – the overall design is markedly different.

Or as Archer’s lawsuit states: “The design of Valo was a significant departure from Vertical’s prior eVTOL aircraft design and now, suddenly, mimics the unique visual product identity of Archer’s Midnight eVTOL.”

It is a design, the US firm says, that “creates the impression of confidence, stability, and stealth”, an overall look which is “uniquely linked to the brand of the company”.

Archer’s two design patents were filed in August 2022, while the so-called ‘utility’ patent related to the flight-control system dates from January the previous year.

While the design patents cover the Midnight’s appearance, the utility patent covers a solution to an “optimisation problem” – balancing the energy drawn across the battery packs and controlling the actuators across multiple electric propulsion units.

Much of Vertical’s rebuttal is legalistic argument – for instance noting that a patent infringement cannot have happened because the Valo is a mock-up at this stage, rather than a real aircraft – but it also addresses the issues at the core of Archer’s complaint.

As part of its claim, Archer lists the history of Vertical’s aircraft designs, starting with the VA-1X that debuted in 2017 – the year before Archer was founded. This featured both a V-tail and a gull-wing with an anhedral tip.

In 2020, the VA-1X was succeeded by the VX4, which retained the V-tail but opted for a largely straight wing.

Archer says the “pivot” to the Valo in late 2025 – with its new more streamlined silhouette and anhedral wingtips – saw the company adopt a design that “closely mimicked the award-winning, visual design of the Archer Midnight aircraft”.

The Valo, however, retains the V-tail of its predecessors, albeit lowered and also incorporating a tail-dragger arrangement, something not present on the Midnight. There are other differences too: eight rather than 12 propellers and the length of the anhedral portion of the wingtip, for example, plus the absence of nose landing gear.

In highlighting the design evolution, Vertical asserts that Archer’s arguments are “self-defeating”.

Or, as it characterises the argument: “Put simply, Archer is accusing Valo of infringement based on features Archer unquestionably did not invent, and that its own complaint establishes were present in Vertical’s earlier designs.”

In essence, Archer is complaining about certain components or features of the Valo that “ it acknowledges Vertical was using before Archer applied for its patents.

“Archer obviously did not invent such elements, and Vertical cannot be held liable for using them,” it states.

For instance, back in 2020, prior to the January 2021 priority date for the patent, the original VX4 featured the same Honeywell flight-control system that Archer now complains about on the Valo.

“Instead of plausibly alleging infringement, Archer has plausibly alleged that Vertical’s earlier prototype is prior art to the asserted [utility] patent,” Vertical’s motion states.

And in respect of the claimed design infringements “Archer’s own allegations thus leave no room for doubt that Vertical, not Archer, was first to have the allegedly ‘unique features’ of Archer’s design, namely, ‘the profile of the wing’ with its downward inflection near the tip, and ‘the distinct V-tail’.

“As for the ‘front profile seamlessly integrating the nose gear’, Valo cannot possibly ‘mimic’ that feature because it has no nose gear – at all.”

The motion also refutes Archer’s claim that Vertical was “willfully blind” to the alleged patent infringement, essentially that it deliberately sought to avoid learning about its rival’s patent portfolio.

“Vertical is aware of Archer’s patent portfolio because Archer’s patents and pending applications are regularly cited as prior art to Vertical’s own patent applications,” its claim argues.

In response, the UK firm says the lawsuit lacks “any facts that show Vertical had pre-suit knowledge of the asserted patents”, with its claim relying on “generalisations and irrelevant allegations”.

A ruling has so far not been made on the motion to dismiss and there is no date at this stage for a full hearing.