Although Cirrus and Diamond appear to be going great guns in the new aircraft market, the industry overall remains moribund. Surprisingly, the twin market isn’t doing so badly. If single-engine sales catch cold when the economy sours, twin sales suffer a sneeze or two, not double pneumonia.

Case in point: 2000 was a moderately strong year for GA. Between them, stalwarts Cessna, Beechcraft/Raytheon and Piper sold 1339 piston singles that year, according to the General Aviation Manufacturers Association. In 2002, the three companies sold 777 singles, a decline of 42 percent. …