Officials said the single-engine jet from Japan’s Air Self-Defense Force was on a training flight with three other F-35s when contact was lost Tuesday evening, public broadcaster NHK reported.The planes, based at Misawa Air Base on the northern tip of the main Japanese island of Honshu, were about 135 kilometers (84 miles) off the east coast of Aomori prefecture when contact was lost, officials said.The pilot of the single-seat fighter is missing, and a search is underway, according to Japan’s Defense Ministry.No problems with the aircraft were reported before it went missing, NHK reported.Japan’s first squadron of the $100 million fighter jets went operational just 11 days ago, with about a dozen of the jets forming the 302nd Squadron at the Misawa base, according to a report from The Diplomat.com.The Japanese jet, a F-35A model, would be the second lost to an accident. A US Marine Corps F-35B crashed in Beaufort, South Carolina, in late September. US defense officials in October said a faulty fuel tube was the likely cause, and all F-35s operated by the United States and its allies were temporarily grounded for inspection.Japan is one of 14 countries in the F-35 program, according to the plane’s maker, Lockheed Martin Corp. Tokyo announced in December it would be buying 147 of the planes, making it the biggest customer for the aircraft besides the United States.At present, some of the Japanese F-35 are assembled in the United States and others at a plant in Nagoya, Japan. It has not been revealed where the plane that went missing Tuesday was built.The F-35 comes in three versions. The F-35A, like the one Japan lost contact with Tuesday, is the one designed for air forces to use off conventional runways. The F-35B, like the one the US Marine Corps lost, is designed for short takeoff and vertical landings. The F-35C model is the US Navy’s version, designed for use off its aircraft carriers.Japan has announced plans to buy 105 of the F-35A models and 42 F-35Bs, which it could eventually use to turn its Izumo-class helicopter destroyers into small aircraft carriers, its first since World War II.The F-35 stealth jet has been called the most expensive weapons system in history, and its development was beset by multiple delays before it was deemed combat ready.The first US combat mission conducted by an F-35 happened in October when a Marine Corps jet launched off the amphibious warship USS Essex struck targets in Afghanistan. In May, Israel announced it had conducted the first combat missions using the F-35 but offered few details.In the Pacific, South Korea and Australia have joined Japan in acquiring the jets.The F-35’s advanced electronic warfare suite can allow seamless integration among users, making the planes strong counters to China’s growing fleet of stealth aircraft, including the J-20 and J-31.CNN’s Yoko Wakatsuki contributed to this report.