Shipments and billings for business aviation jets and turboprops reached all-time highs in the second quarter, according to data released this afternoon by the General Aviation Manufacturers Association (GAMA), while the piston market took a dive. Industry billings for the first half totaled $12.1 billion, a 24.1-percent increase over the first six months of last year. “Shipments in the business jet and turboprop segments continue to rise steadily,” said GAMA president and CEO Pete Bunce. “Expanding worldwide markets are having a positive effect on the turbine segments of our industry,” he said. Despite uncertainty about fuel prices and the North American economy, “the energy surrounding the entire spectrum of general aviation remains robust,” he added. Turboprop shipments increased from 186 aircraft in the first half of last year to 222 aircraft in the same period this year. First-half business jet shipments jumped to 663 airplanes, up 39.3 percent from the 476 aircraft delivered in the same period last year. Manufacturers shipped 1,034 piston-powered airplanes in the first six months of this year, down 15.7 percent from the 1,226 airplanes delivered in the same period last year.