Joby Aviation is acquiring Dayton, Ohio-based defence technology firm Resonant Sciences in a $500 million deal, as the electric air taxi maker seeks to build out its military business. The move reflects a broader trend among electric aviation developers, who are turning to defence contracts for revenue as regulatory approval for passenger-carrying air taxis remains years away and costs continue to mount.

Joby will fund the acquisition with $450 million in cash and $50 million in equity, with the deal expected to close in early 2027; Resonant will operate as Joby's dedicated defence division while its existing commercial arm focuses on air taxis due to launch later this year. Resonant, founded in 2015 and employing around 250 people, makes sensors, antennas and signal-processing systems that help aircraft communicate and evade detection in warzones, with products already qualified across more than 20 airframes. Joby has pursued military ties since 2016 and last week reported a $245.4 million quarterly net loss against just $38.6 million in revenue, underlining the financial pressure driving the shift towards defence work.