Business and personal jet manufacturers are optimistic for long-term investment in their aircraft despite the ongoing struggles and a credit crunch in the U.S. economy, aviation industry officials said. While there is a lot of angst over the availability of credit the industry remains in a wait and see mode about what will happen in the near term, said Peter Bunce, president and CEO of the General Aviation Manufacturers Association at the National Business Aviation Association convention in Orlando. Aircraft manufacturers made changes during the economic downturn that hit the industry following the Sept. 11 terrorist attacks and are doing so again, said NBAA President and CEO Ed Bolen. The companies are beefing up their collection of deposits and making more deals with individual companies and cutting back in orders with fractional owners, Bolen said. In the long term, the manufacturers are “bullish” that business owners will buy their planes, Bolen said. “That is reflective of every manufacturer is working on a clean sheet airplane,” Bolen said. Clean sheet aircraft have better fuel economy, reduced emissions and carry less weight. The 61st annual convention is expected to draw 30,000 people over its three days.