"If airlines are worried, they sure aren't showing it," said Oppenheimer analyst Yair Reiner in a note to clients.
Investors rallied behind the company Wednesday, sending shares up by 3.5 percent to $76.74. That followed a two-day drop of 4.6 percent. Boeing shares had gained 11 percent in the three months prior to Monday as investors anticipated a growing flow of cash from Boeing's faster production of its big planes.
Besides the fire, another Japan Airlines plane leaked 40 gallons of fuel at Boston Logan on Tuesday. The airline said an open valve caused one tank to overflow through a vent. Last month a United Airlines 787 flying from Houston to Newark, N.J., diverted to New Orleans because of an electrical problem with a power distribution panel.
Japan's All Nippon Airways, meanwhile, said it cancelled a domestic flight to Tokyo on Wednesday after a computer wrongly indicated there was a problem with the Boeing 787's brakes.
Boeing insisted on Wednesday that the 787's problems are no worse than what it experienced when its 777 was new in the mid-1990s. That plane is now one of its top-sellers and is well-liked by airlines.
"Just like any new airplane program, we work through those issues and move on," said Mike Sinnett, the 787 chief engineer. He added, "We're not satisfied until our reliability and our performance are 100 percent."
Sinnett didn't say so, but other new planes have had their own issues, including the Airbus A380 superjumbo. Small cracks have been discovered on the wings, and in 2010 a Rolls Royce engine on a Qantas flight exploded in mid-flight.
He said the nature of lithium ion batteries means no fire extinguisher system will stop them from burning once they start. The NTSB said it took firefighters 40 minutes to put out Monday's fire.
Sinnett said Boeing has no plans to replace the lithium ion batteries with another type. If he had to re-do the choice to go with lithium ion, he said, he'd make the same choice today.
AP Airlines reporter Scott Mayerowitz in New York contributed to this report.