LOS ANGELES (AP) ¿ Aerospace engineering firm Ducommun Inc. said Monday its third-quarter profit slipped on higher interest costs for increased debt and a higher tax rate. However, the results easily beat Wall Street expectations and its share soared in afternoon trading. Net income of $6.2 million fell 1 percent from $6.3 million, although earnings per share were flat at 59 cents year over year. Revenue of $109.9 million for the quarter ended Oct. 3 improved 9 percent from $100.9 million in the same period last year. Analysts surveyed by Thomson Reuters expected earnings of 52 cents per share on revenue of $111.1 million. The Los Angeles company credited the sales increase to its acquisition last December of DynaBil Industries Inc. The business generated sales of $11.1 million in the quarter. Joseph C. Berenato, chairman and CEO, said excluding the acquisition, year-over-year sales were largely flat despite a "precipitous decline" in commercial aircraft sales, particularly for regional and business jets. Ducommun benefited from an increase in military sales for programs such as Northrop Grumman's X-47B UCAS, the Boeing C-17 and radar system upgrades for military fighter aircraft. In addition, an increase in sales for Sikorsky's Blackhawk helicopter more than offset a decline in sales for the Boeing Apache helicopter, Ducommun said. Shares of Ducommun jumped 81 cents, or nearly 5 percent, to $17.83 in afternoon trading.