At the Aviation Insurance Association convention earlier this year, industry experts reported a mini-boom that is benefiting the insured, large and small. The reason: a credit crunch throughout much of the economy, triggered by the U.S. sub-prime loan debacle, has been driving capital, especially private-equity funds, toward less risky investments, including aviation insurance. With a favorable loss history and an upscale worldwide clientele, the field presents an attractive vehicle in an uncertain time, explained representatives of some of the largest aviation insurers.