A Japan Airlines Boeing 787 readying for takeoff at at Boston Logan International Airport today sprang a leak from its number one engine, spilling approximately 40 gallons of fuel onto the runway, and had to be towed back to the gate.
It was the second incident involving one of Boeing's new Dreamliner planes in as many days for the airline.
The plane was scheduled to depart Boston for Tokyo today at 12 p.m., carrying 178 passengers and 11 crew. No one was injured, and the plane departed for Tokyo at approximately 4 p.m.
The FAA last month ordered inspections of potential fuel-line leaks on all 787s.
"A mechanical issue was reported by the crew on today's flight JL007 08JAN, and the aircraft is now returning to the gate. Details of the mechanical are not yet confirmed," the airline said in a statement.
The incident comes just one day after a fire broke out on an empty Boeing 787 Dreamliner jet, also at Logan airport, after a non-stop flight from Tokyo, prompting more safety concerns about the new plane since its 2011 release. The plane involved in the incident today was not the same plane that had the fire the day before.
Both incidents are being investigated.
"The FAA is looking into a reported Japan Airlines 787 fuel leak at Logan Airport today and continues to look into the cause of yesterday's 787 incident at Logan," the FAA said.
The incident Monday occurred when an electrical fire broke out on board the Japan Airlines jet 30 minutes after 173 passengers and 11 crew members got off the plane. The Massachusetts Port Authority's fire chief, Bob Donahue, said the fire began in a battery pack for the plane's auxiliary power unit, which runs the jet's electrical systems when it is not getting power from its engines.
No major injuries were reported and one firefighter had skin irritation after contact with a chemical used to douse the fire, Donahue said.
Investigators for the National Transportation Safety Board found "severe fire damage" on the auxiliary power unit battery. The battery was in operation before the fire broke out, according to the NTSB. Two additional NTSB investigators have been sent to Boston to work the case.
The flight landed incident-free around 10:15 a.m., but a mechanic working in the cockpit was confronted minutes later by smoke billowing from electrical systems in the belly of the plane.
"We observed a heavy smoke condition throughout the entire cabin," Donahue said.
Fire crews using infrared equipment found the flames in a small compartment in the plane's belly and had the fire out in about 20 minutes, he said. There was a flare-up later when a battery exploded, he added.
Japan Airlines said in a statement Monday, "Safety is the foundation of JAL's operations and while no passengers were injured in this incident, we deeply apologize for causing our customers concern and inconvenience. We are now working closely with NTSB and Boeing in determining the cause of this incident."
"We're aware of the situation and are working with our customer," Boeing said in a statement.
Boeing has sold more than 800 of the planes around the world with only six flying domestically. The plane, mostly made of carbon fiber, was first released in 2011.
In the wake of the incident Monday, United Airlines inspected its six Boeing 787s overnight. The airline did not share its findings, but did say all six 787s were flying today.
"We continue to work closely with Boeing on the reliability of our 787s," the airline said in a statement.
On the same day the FAA inspection was ordered last month, a United Airlines 787 flight from Houston to Newark, N.J., was diverted to New Orleans because of a generator failure. A similar fire broke out during the 787's testing phase in 2010.
"This event occurred in the same avionics bay where they had problems before," said John Hansman, MIT professor of aeronautics and astronautics. "So it raises a lot of questions that will be looked at as quickly as possible."
But Hansman said he believes this is just a new plane built differently with new systems and materials.
"I wouldn't be concerned as a passenger. This is a very good airplane, but it's very advanced. It's pushing the envelope," Hansman said.
Boeing said in a statement that the fire Monday appears to be unrelated to previous incidents involving the Dreamliner.
"Nothing that we've seen in this case indicates a relationship to any previous 787 power system events, which involved power panel faults elsewhere in the aft electrical equipment bay," the statement said in part.
Airlines are buying the new planes because they're cheaper to fly and more efficient, but they're going to sell would-be passengers on feature comforts such as the air itself.
Because the plane is made of plastic, it is more flexible so air pressure inside the plane can be kept higher. The maker says the improvement in air pressure leads to less jet lag, as well as less dry mouth and skin for passengers.
Blake Emery, the director of differentiation strategy for Boeing, told ABC News in November the Dreamliner offers "significant" changes from today's flying experience.
Such changes include windows that are 30 percent bigger and storage bins built to accommodate roll-aboard bags common among today's fliers.