Two U.S. Marine Corps F/A-18 Hornets and a KC-130J Hercules fly during a demonstration over Detroit in September 2017. A mishap between a Hornet and Hercules near Japan early Dec. 6 has prompted a search for missing Marines. (U.S. Marine Corps photo by Sgt. Gregory Boyd) Dan Lamothe Reporter covering the Pentagon and the U.S. military December 5 at 5:31 PM U.S. Marines and Japanese authorities were searching off the coast of Japan for six Marines after a mishap involving a fighter jet and a plane used for transporting troops and refueling, Marine officials said early Thursday. One Marine was rescued, officials said in a statement. The incident occurred after the planes took off from Marine Corps Air Station Iwakuni in Japan, officials said. The aircraft — an F/A-18 Hornet and a KC-130 Hercules — were conducting “regularly scheduled training” at the time, and Japanese authorities immediately launched search-and-rescue aircraft. “The circumstances of the mishap are currently under investigation,” the statement said. It was not clear immediately clear whether the aircraft collided while crossing in the air, or if the KC-130 was in the process of refueling the Hornet when the incident occurred. Aerial refueling with the KC-130 calls for another aircraft to pull slightly below and behind the tanker plane, with hoses extended from 3,600-gallon stainless steel tanks on the KC-130′s wings to one or two other aircraft simultaneously. The KC-130 also can be used to transport ground troops. In July 2017, a KC-130T crashed in Mississippi while flying from Stewart Air National Guard Base in New York to Naval Air Facility El Centro in California, killing all 16 Marines aboard and prompting the military to ground many other C-130s afterward. The Marine Corps announced Wednesday night that an investigation into the crash in Mississippi found that an “in-flight departure” of one of the plane’s propellers from a wing and into the aircraft’s fuselage caused the disaster. “The investigation determined that the aircraft’s propeller did not receive proper depot-level maintenance during its last overhaul in in September 2011, which missed corrosion that may have contributed to the propeller blade liberating in-flight,” the service said in a news release.