Boeing Co. tumbled after an analyst downgraded the stock to “underperform” and said the U.S. planemaker stood little chance of fully recovering almost $29 billion that’s been sunk into producing the 787 Dreamliner jet. The shares fell 1.9 percent to $130.11 at 11:25 a.m. in New York. The stock earlier dropped 3.2 percent, the most intraday since Feb. 24. Boeing had declined 8.2 percent this year through Tuesday, the fourth-worst performance among the 30 members of the Dow Jones Industrial Average. The manufacturer has touted the substantial cash it stands to generate from jet production to meet a near-record order backlog and the profit to be made on the 787, its marquee aircraft.  “In the longer term, we continue to target levels of profitability for the 787 that are consistent with our more mature production programs,” Boeing spokesman Chaz Bickers said by e-mail. But Ron Epstein, an analyst at Bank of America Corp., estimated that cash flowing from the Dreamliner by 2022 will be $14 billion rather than the $29 billion assumed in Boeing’s outlook. Profit Needed To reach that number and eliminate the almost $29 billion in deferred production costs already accumulated by the 787 program, Boeing would need to generate a profit of $30 million for each of the 907 Dreamliners it projects making for accounting purposes, Epstein wrote. That profit goal is “unachievable,” he said. Generating $16 million in profit per plane was more realistic, Epstein wrote. Boeing is likely to take a charge on the 787 program or increase the projection of 1,300 jets it is using to estimate future profits under U.S. program accounting rules, Epstein said. Bloomberg reported in February that the U.S. Securities and Exchange Commission is investigating Boeing’s forecasts regarding the profitability of the Dreamliner and the 747 jumbo jet. Current Projections Boeing has maintained that it expects the 787 to recoup costs and turn a slight profit under current accounting projections. The effort should be bolstered as the planemaker speeds Dreamliner production to 12 jets a month this year and 14 monthly later in the decade, both records for long-range aircraft. The mix of Dreamliners that Boeing is making is also shifting to the largest and priciest 787 models, where profit margins will be bolstered from the lessons learned over a decade of manufacturing the carbon-fiber jets. “We see a strong future for the 787 as we continue to reduce production costs and deliver more of our newer, higher-value variants, the 787-9 and 787-10,” Bickers said, noting that Boeing holds more than 600 orders for the largest models in the three-jet Dreamliner lineup. “We continue to see strong customer interest for the 787 as airlines embrace its performance and market expansion potential.”