An open valve on the aircraft caused fuel to leak on Sunday from a nozzle on the left wing used to remove fuel, a company spokeswoman said. The jet is out of service after spilling about 40 gallons of fuel onto the airport taxiway in Boston because of a separate valve-related problem.

In Boston, a different valve on the plane opened, causing fuel to flow from the center tank to the left main tank. When that tank filled up, it overflowed into a surge tank and came out through a vent. The spill happened on Tuesday as the plane was taxiing for takeoff on a flight to Tokyo. It made the flight about four hours later.

The causes of both incidents are unknown, the JAL spokeswoman added. There is no timetable for the plane to return to service.

“We are aware of the event and are working with our customer,” a Boeing spokesman, Marc Birtel, said of the leak in Tokyo.

On Friday, the United States government ordered a broad review of the Boeing 787, citing concern over a battery that caught fire last week, also on a JAL plane in Boston, and other problems. The government and Boeing insisted the passenger jet remained safe to fly.

The 787 represents the boldest bet Boeing has made on a plane in more than a decade. Because much of its financial performance is riding on the 787, Boeing is trying to double production to 10 jets a month this year to fulfill nearly 800 orders.

Article source: http://www.nytimes.com/2013/01/14/business/global/japan-airlines-says-787-jet-leaked-fuel-during-safety-test.html?partner=rss&emc=rss