Wisk Aero LLC v. Archer Aviation Inc.

Background

Wisk moved for permission to amend its infringement contentions—its required detailed statements identifying how Archer’s products allegedly infringe Wisk’s patents. The proposed amendments concerned U.S. Patent No. 10,110,033, involving a battery charging system, and U.S. Patent No. 9,764,833, involving a ventilated rotor mounted on an aircraft boom.

Wisk said it learned during discovery that Electro.Aero, an Australian supplier, had sold Archer’s charging system and provided documents containing source code. Wisk also relied on deposition testimony from Diederik Marius, an Archer engineer formerly associated with Wisk. The proposed amendments identified additional charging-system information, added or quoted newly produced documents and testimony, refined Wisk’s existing infringement theories, and clarified that the allegations applied to components of Archer’s Midnight aircraft.

Archer stipulated to some minor amendments but opposed the more significant ones. It argued that Wisk lacked good cause and diligence, was asserting new infringement theories, was changing the products or components accused of infringement, and would prejudice Archer by requiring additional discovery or claim construction. Archer also argued that some allegations involving Midnight were premature because the product had not been fully finalized.

Legal standard

Under the Patent Local Rules, infringement contentions may be amended only with a court order based on a timely showing of good cause. Good cause generally requires diligence in discovering the basis for amendment and seeking amendment, along with an assessment of prejudice to the opposing party. Recent discovery of previously unavailable nonpublic information about an accused product can support amendment.

Court’s analysis

The court found that Wisk’s amendments did not add new theories of infringement. Instead, they provided more detail about existing theories, cited newly produced information, and clarified that the original allegations covered the battery and boom assemblies used in Midnight. The court also found that Wisk’s earlier contentions had already focused substantially on those component technologies rather than only on the aircraft as a whole.

The court concluded that Wisk acted diligently. Wisk pursued discovery from Electro.Aero and received important information in June 2022. Wisk also received more detailed information about Midnight’s boom-mounted rotors in July 2022 and promptly sought amendment afterward. The court found the time taken to prepare and file the motion reasonable.

The court further found no significant prejudice to Archer. The amendments did not change Wisk’s underlying infringement or doctrine-of-equivalents theories. Archer could later present evidence that its products did not use the technology Wisk identified, and it could request additional claim construction or discovery if necessary. The court was not convinced that another claim-construction hearing would be required.

Disposition

The court granted Wisk’s Motion for Leave to Amend its Infringement Contentions. The court also granted Wisk’s and Archer’s Motions to File Under Seal because the materials contained sensitive confidential information about the parties and trade secrets. The order did not decide whether Archer actually infringed either patent.