US-based general aviation airframe manufacturers have increased total billings by 41.6 per cent so far in 1999, according to the General Aviation Manufacturers Association (GAMA).\rShipments have grown by more than one eighth through the third quarter of 1999, and total billing has already reached $5.5 billion for the first nine months of this year, compared to $3.9 billion in 1998, GAMA says. Total aircraft shipments also increased by 200 for the same period, to 1,692.\rJet deliveries were up 26.2 per cent with 352 aircraft shipped in the first nine months of 1999 compared to 279 units through for 1998 up to September. Turboprops increased nine per cent in this time.\r"Looking at the first nine months of 1999, we are seeing tremendous market activity throughout the industry. It's shaping up to be another great year for aviation," commented GAMA president Ed Bolen.