“The air cargo market recovery that began in late 2013 has stalled in recent months and slowed demand for the 747-8 freighter,” Ray Conner, chief executive of Boeing Commercial Airplanes, said in a statement. Boeing has disclosed in its regulatory filings for months that the costs of making the 747-8 were outstripping sales, suggesting an imbalance of about $1 billion, so the charge is somewhat less than analysts had expected and had already been factored into Boeing’s stock price. Boeing shares slipped in extended trade to $121.60 from a close of $123.40 on the New York Stock Exchange.