In the largest protests of its kind to date, as many as 100,000 people in Okinawa, Japan on Sunday the U.S. military's plans to deploy two dozen V-22 Osprey tilt-rotor aircraft there. The Marines want the aircraft available for patrolling parts of the South China Sea, where several countries dispute who controls the waters. But many Japanese are worried about the Osprey's safety record. At the protest, they latched on to reports of a Osprey making an emergency landing in South Carolina last week due to an oil leak; no one was injured in that incident. The delivery of the Ospreys has already been delayed several times over previous protests. Twelve of the aircraft are on another Japanese island, but grounded by Japanese officials until investigations into Osprey crashes in Florida and Morocco are complete. In the mean time, U.S. troops and their Japanese counterparts are using slower and noisier Vietnam War-era CH-46 Sea Knight helicopters for their missions.