Wisk Aero, a flying taxi startup backed by Boeing (BA.N) and Google co-founder Larry Page"s Kitty Hawk Corp, asked a California court on Wednesday to stop the alleged use of its trade secrets by rival Archer Aviation and said it was cooperating with a criminal U.S. probe. Wisk and Archer, a special purpose acquisition company (SPAC) whose investors include United Airlines (UAL.O), compete in the increasingly crowded market for electric vertical takeoff and landing aircraft, or eVTOLs. Wisk"s motion for a preliminary injunction and hearing on July 7 is part of its ongoing litigation against Archer, which it accuses of stealing trade secrets and infringing on its patents as the new Palo Alto-based SPAC seeks to certify its eVOTL aircraft by 2024. Aside from its lawsuit filed in April, a Wisk spokesman said the company continues to cooperate with the FBI and U.S. Department of Justice "on their criminal investigation into Archer relating to the theft and use of Wisk’s intellectual property." "This (is) a baseless motion in a baseless lawsuit," a spokeswoman for Archer said, adding that the company is moving forward with its business plans, "including the development, certification and production of its proprietary aircraft." Asked about the criminal probe, she said: "We have no further comment on the specifics of the investigation at this time." United declined to comment. The availability of eVTOL aircraft, which take off like helicopters and fly like planes, is widely expected to revolutionize urban mobility. Conservative estimates suggest the market could exceed $1 trillion by 2040, Wisk said in its court filing. The filing called Archer"s development timeline too short to be true. "The theft of our highly confidential files, the virtual copy of Wisk’s design from a confidential patent application, and Archer’s startlingly short operational history make clear that Archer’s program is built on Wisk’s intellectual property," the Wisk spokesman said. Beyond the United States, Europe could see flying taxis enter service in 2024, the region"s top aviation regulator said on Wednesday.