Teledyne Technologies Inc. saw a drop in sales for aircraft engines and commercial and government purchases of its hydrogen generators for the third quarter. Overall, the Thousand Oaks company had a 20 percent increase in net income for the quarter. The company reported a net income of $27.1 million, or $0.75 per diluted share, on revenues of $409 million for the quarter ending Sept. 30. For the same period a year ago, the company had a net income of $22.6 million, or $0.63 per diluted share, on revenues of $364 million. The electronics and communications and the systems engineering solutions business units showed an increase in revenues for the quarter. Sales in the aerospace and engines unit dropped by 3.6 percent for the quarter and in the energy sales unit by 27 percent compared with the third quarter 2006. The company sold fewer of its turbine and piston engine overhaul services. The lower turbine engine sales were primarily for the Harpoon engine.