Small plane orders fell last year, the industry said.

The General Aviation Industry Assn., which includes makers of business, commuter, cargo and personal transportation planes, said 1986 shipments of 1,495 U.S.-built planes worth $1.26 billion were hurt by tax uncertainties and product liability costs. Although association President Edward W. Stimpson termed results “better than expected,” he said the number of planes shipped was still the lowest since before World War II, largely because of soaring liability costs averaging nearly $100,000 for each plane shipped last year.