CHICAGO (CBS) — For the second time in two days, officials are investigating a mechanical problem involving a Boeing 787 Dreamliner jet.

Tuesday afternoon, a 787 was towed back to the gate for inspection at Logan International Airport in Boston, after fuel began leaking shortly before takeoff. The Japan Airlines flight to Tokyo was carrying 178 passengers and 11 crew members.

A day earlier, a fire broke out in the battery of another Japan Airlines 787 after passengers had left the plane.

CBS 2’s Chris Martinez reports shares of Chicago-based Boeing Co. have fallen about 5 percent since the first incident in Boston.

The two recent incidents come in the wake of electrical panel issues in three other 787 jets in December.

One of those, a United Airlines jet, had to make an emergency landing in New Orleans.

Aviation experts said such problems are expected in any new aircraft.

But passengers just want to know if the jets are safe.

CBS News Travel Editor Peter Greenberg said airline passengers shouldn’t be worried about boarding a 787 Dreamliner.

“The reason for that is, this plane was already certificated by the FAA as airworthy. It’s been going through a myriad of tests. I’m not concerned about that at all,” he said. “The number of incidents here is really not consequential, and it’s not surprising. … It’s getting a lot of publicity, and that may be a good thing to be able to fix that problem faster, whatever that problem is.”

Both the Federal Aviation Administration and Boeing have said they’re trying to figure out exactly what caused the recent problems. Both are investigating the incidents.

Boeing said they don’t believe most of the problems are related.

As for the plane with the fuel leak on Tuesday, a Boeing spokesperson said that leak was fixed, and the aircraft did depart for Tokyo late Tuesday afternoon.

Watch & Listen LIVE