Boeing Traces Source of Dreamliner Fire; Another 787 Has Problems

One day after a Dreamliner caught on fire, Boeing found itself facing another 787 with problems—a fuel leak that sent the aircraft operated by Japan Airlines back to the gate at Boston's Logan International Airport.

This at a time when the aviation company said it has traced the source of the fire to a lithium ion battery in the Auxiliary Power Unit (APU).

Meanwhile, a second straight day of headlines and pictures of emergency crews surrounding a Dreamliner weighed on Boeing shares. Shares of the Dow component fell another $2 (2.63 percent) on heavy volume. It marks the worst two consecutive days for Boeing shares since Oct. 31 and Nov. 1 of 2011.

Lithium ion battery source of fire

While the National Transportation Safety Board has decided to send two more investigators to Boston to work on the Dreamliner fire case, Boeing said it traced the fire to a battery in the planes auxiliary power unit. (Read More: Fire Puts Dreamliner Under Scrutiny.)

NTSB Investigator Mike Bauer inside the Boeing 787 under investigation at Boston's Logan Airport.
NTSB Investigator Mike Bauer inside the Boeing 787 under investigation at Boston's Logan Airport.

"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," Boeing spokeswoman Lori Gunter said.

That initial determination is important since three other Dreamliners in recent weeks have experienced either electrical problems or have had their electrical systems checked for potential issues.

Meanwhile, airlines currently flying the Dreamliner have been quietly inspecting their planes to make sure the APU battery and its wiring is properly connected and operating as it should.

All Nippon Airlines, which has 17 Dreamliners, said it made inspections overnight at the urging of Japan's Ministry of Transportation. ANA found no problems.

That was not the case with United Airlines according to the Wall Street Journal. It said United found improper wiring on one Dreamliner battery. United would not comment on the report.

Fuel Leak on Boston runway

For a time on Tuesday, it seemed like deja vu, with pictures coming out of Boston showing emergency crews surrounding a Japan Airlines Dreamliner. (Read More: After Boeing 787 Fire, Another Dreamliner Has Fuel Leak.)

This time, the problem involved a fuel leak. The plane lost approximately 40 gallons of jet fuel before being brought back into the gate for an inspection. While the plane eventually took off for Tokyo, the fuel leak was a reminder of the FAA airworthiness directive in December requiring airlines to check the fuel line connections on all Dreamliners.

Long-term damage to Boeing & the Dreamliner

This is not the first high profile problem involving the Dreamliner. Given its complexity and technological advancements, launching the 787 has been filled with delays and setbacks. (Read More: Is the Boeing 787 Dreamliner Truly a Game Changer?)

Now that the Dreamliner is in service with 46 delivered to airlines around the world, these latest problems are magnified. They also come as Boeing is in the midst of ramping up production of the Dreamliner. The company still has a backlog of more than 800 Dreamliner orders and so far there's no indication airlines have cancelled 787 orders because of the recent problems.

"There are many new technologies in this plane, so inevitably there will be many glitches," said Richard Aboulafia, an aviation consultant with the Teal Group in Washington, D.C. "But put the words 'fire' and 'new jetliner' together in a sentence and you're bound to scare travelers and airlines. Boeing will be able to make this situation right, but they need to act fast to avoid serious problems with customers."

—By CNBC's Phil LeBeau; Follow him on Twitter @LeBeauCarNews