Appeals Court Reinstates $81 Million Verdict Against Boeing for Interfering with Zunum Aero

Washington, August 18 - In a legal debate, a U.S. appeals court has reinstated an $81 million verdict against Boeing, ruling that the aerospace giant interfered with Zunum Aero, a Bothell, Washington-based startup focused on developing hybrid-electric regional aircraft. The decision, handed down by the Ninth Circuit on August 14, 2025, marks a pivotal moment in a years-long dispute that began when Zunum accused Boeing of misappropriating trade secrets and undermining its business prospects. Zunum, founded with ambitions to revolutionize regional air travel through sustainable aviation, had partnered with Boeing’s venture arm, HorizonX, in 2017, receiving $9 million in loans. However, the relationship soured, leading to Zunum’s financial struggles and eventual suspension of operations in 2019. The appeals court’s ruling reverses a lower court’s decision to overturn the original jury verdict from May 2024, which found Boeing liable for stealing 11 of 19 alleged trade secrets, breaching a non-disclosure agreement (NDA), and tortiously interfering with Zunum’s prospective partnership with French aerospace company Safran.

The original trial in May 2024 revealed a complex dynamic between Zunum and Boeing. Zunum alleged that Boeing, while posing as a supportive investor, used its access to the startup’s proprietary information to advance its own hybrid-electric aircraft initiatives. The jury determined that Boeing’s actions were willful and malicious, particularly in misappropriating trade secrets related to Zunum’s innovative designs for a 12-seat hybrid-electric regional airliner, the ZA10, intended to enter the market by 2022. Additionally, Boeing was found to have disrupted Zunum’s efforts to secure further investment and collaboration with Safran, which had committed to developing a specialized engine for Zunum’s aircraft. The jury’s $81 million award included damages for trade secret theft and interference, though a federal judge, James Robart, overturned this verdict in August 2024, citing insufficient evidence that Zunum’s shared information constituted trade secrets or that it had a viable business expectancy with Safran. Zunum’s appeal challenged this reversal, arguing that the jury’s findings were well-supported.

The Ninth Circuit’s unanimous decision to reinstate the verdict is a major victory for Zunum and a cautionary tale for large corporations engaging with startups. The court rejected Boeing’s arguments for a new trial and reassigned the case to a new judge for post-trial proceedings, citing concerns over the original judge’s stock trades in Boeing, which raised questions of impartiality. The ruling underscores the importance of protecting intellectual property in emerging industries like electric aviation, where startups often rely on strategic partnerships with established players. For Zunum, the reinstated award validates its claims that Boeing’s actions not only stifled its growth but also leveraged its technology to gain a competitive edge. The decision also highlights the risks of “invest, learn, compete” dynamics, where large firms may exploit their access to a startup’s innovations under the guise of investment.

This case has broader implications for the aerospace industry, particularly in the rapidly evolving field of electric and hybrid-electric aviation. Zunum’s vision of sustainable regional air travel, though halted, represented a bold step toward reducing aviation’s environmental impact. The reinstated verdict may encourage other startups to pursue legal recourse against larger firms that misuse their intellectual property. For Boeing, the ruling adds to its legal and financial challenges, requiring it to repay the $81 million award while still holding Zunum accountable for the $9 million in loans plus interest. As the case moves forward under a new judge, it will likely shape how venture governance and intellectual property rights are managed in high-stakes industries, emphasizing the need for clear boundaries in strategic partnerships. The outcome serves as a reminder that innovation in aviation, while promising, is fraught with competitive tensions that can lead to costly legal battles.