Smoldering metal shavings inside Boeing's first 787 Dreamliner set off a fire alarm Wednesday morning, but delayed work for just a half-hour.

More ominously, several Wall Street analysts warned in notes to investor clients that the new airplane program could face further schedule slippage.

The warnings were spurred by a report posted on the Web site of Flight International magazine and by rumors circulating in the industry and in the financial markets of more delays beyond the six-month one announced in October.

"The rumors are swirling and clients have been calling me," said Morgan Stanley analyst Heidi Wood.

In her note, she said the first Dreamliner still had no avionics or wiring in the cockpit in mid-December and that the speculation of further delay is "likely true." She wrote that the jet's first flight, supposed to happen in March, "might occur closer to late April/May."

Two people who have talked with several local 787 engineers independently supported Woods' assertion. They added that just before Christmas, the plane's fuselage remained largely a shell, with few systems installed.

After taking over as new 787 program leader last year, Boeing Vice President Pat Shanahan identified the next big benchmark: turning on the first airplane's electrical power, a milestone known as Power On. He said that should occur around the end of January.

In her note Wednesday, Wood said it should take about two months to move from the airplane's mid-December assembly status to Power On.

"The math of this alone translates to the plane being powered up more like mid-February, even if everything else went fine," Wood wrote.

"Factoring odds for additional complications (Murphy's law) points to Power On closer to end of February."

Wood, formerly among the most bullish of Wall Street's Boeing watchers, downgraded the stock in December.

A report on the FlightBlogger Web site Wednesday cited unidentified sources in Everett forecasting a three-week slip in the schedule beyond the previously acknowledged delay.

Bank of America analyst Robert Stallard saw the bright side of that report, telling clients that three weeks "should not cause too much concern." He wrote that he's been hearing gloomier predictions of new delays "running into several months."

Boeing spokeswoman Yvonne Leach said she could neither confirm nor deny the FlightBlogger report.

She declined to reaffirm Shanahan's prediction of the timing of Power On, saying only: "We are doing everything we can to focus on that milestone."

Boeing's revised schedule calls for the first Dreamliner delivery at the end of 2008

Boeing's shares have slid nearly 10 percent since a 787 program update in early December, closing Wednesday at just above $80. That's about twice the Dow's decline during that period.

In a client note Wednesday, Sanford Bernstein analyst Doug Harned attributed the drop to "rising 787 concerns, which are consistent with our assumption of a 12-month (rather than six-month) delay scenario," Bloomberg News reported.

The fire scare inside Dreamliner No. 1 happened at 9 a.m. Wednesday.

Hot titanium shavings burned through a vacuum-cleaner bag used to sweep them up and smoldered on a floor mat, Leach said.

A fire alarm went off and the plane was briefly evacuated.

No harm was done. There were no flames, only smoke, she said.

Dominic Gates: 206-464-2963 or dgates@seattletimes.com