Two Oceanside residents were arrested Thursday on suspicion of illegal transportation of narcotics after their small plane made an emergency landing on State Route 76, the Oceanside Police Department said. At about 1:43 a.m. Thursday, OPD officers responded to a call that a plane experienced engine failure and had to make an emergency landing on SR-76 near Canyon Drive, according to a police statement. The plane’s two occupants were not injured. A search of the plane revealed a large quantity of narcotics, the OPD statement said. Both occupants of the plane were taken into custody. The Federal Aviation Administration is investigating the circumstances of the emergency landing. As of 6 a.m. Thursday, the plane is still on the roadway. Motorists are asked to drive with caution in the area. This story uses functionality that may not work in our app. Click here to open the story in your web browser.