A federal appeals court has rejected the Federal Aviation Administration's ruling that the Cape Wind project's turbines present "no hazard" to aviation, overturning a vital clearance for the nation's first offshore wind farm.

A decision Friday from the U.S. Court of Appeals for the District of Columbia said the FAA didn't adequately determine whether the planned 130 turbines, each 440 feet tall, would pose a danger to pilots flying by visual flight rules.

The court ordered the "no hazard" determinations vacated and remanded back to the FAA.

It also ruled that if the FAA found the project posed aviation risks, the U.S. Interior Department would likely revoke or modify the lease granted Cape Wind — the first granted to a U.S. offshore wind project.

The decision signals further delays for the project, which has struggled to find financing.