Tokyo (CNN) -- A Japan Airlines' inspection of a Boeing 787 Dreamliner involved in a fuel spill last week at Boston's Logan International Airport found a new leak from a nozzle on the plane's left wing, a JAL spokesman said Sunday.
The leak was different from one that caused a flight on January 8 to be delayed by four hours, the airline said.
The jet was bound for Tokyo on January 8 when a pilot on another airplane spotted the 787 leaking fuel just before takeoff.
The ongoing investigation found a new leak in a nozzle used to remove fuel.
The new 787 Dreamliner has been the subject of negative publicity after a string of recent mechanical and other problems. Troubles dating back just four months include reports of an oil leak, a fuel leak, engine cracks and a damaged cockpit window. This all follows a very difficult development history that included a series of production setbacks and other delays before the plane entered service in 2011.
The U.S. Federal Aviation Administration, which is responsible for air safety, launched a comprehensive examination on Friday of the Dreamliner's design, manufacture and assembly.
More than 150 Dreamliner flights occur daily, according to Boeing. United Airlines -- which has six 787s -- debuted the nation's first domestic Dreamliner routes last November with much fanfare.
Ray Conner, the head of Boeing's commercial airplanes unit, said Friday that Boeing is convinced of the aircraft's safety and that the airlines that have bought the plane are also confident in its safety.
"These planes are safe," he said. "We welcome any opportunity to further assure people outside the industry."
Worldwide, Boeing has delivered 50 Dreamliners. Several hundred are under order, making its success crucial for Boeing, which had not designed a new commercial jetliner in years before unveiling the Dreamliner.
The twin-engine jetliner is heralded for its mostly carbon fiber construction, which reduces weight. Its fuel-saving possibilities, cutting edge technology, operational versatility and cabin appointments generated enormous interest from airlines, initially overseas.
One passenger said Friday he would avoid flying on a 787 for the time being.
"I am wary of a plane model that has fire problems and leaks fuel," said Atlanta-based businessman Bobby Burns, a project manager who takes more than 50 trips a year. "I think of it the same as a new car model: wait a year or two to get all the 'recalls' sorted out."
CNN's Junko Ogura contributed to this report.