Piper Aircraft laid off another 150 workers last month, not because of the slow economy, as in previous layoffs, but due solely to last year’s ADs and recall of Textron Lycoming engines, according to a company spokesman. Piper Saratogas and Mirages are among the airplanes powered by Lycoming engines. Piper also claimed the problem stopped the “step up” process wherein owners of Saratogas and Mirages move up to the Meridian turboprop. Piper told AIN that many of its dealers are considering suing Textron Lycoming. This fourth round of layoffs since just after 9/11 leaves the Vero Beach, Fla. manufacturer with about 850 employees, down nearly half from the 1,500 workers at Piper before 9/11.