CubCrafters has taken the unusual step of certifying its X-Cub in the primary category, even though it’s already certified under Part 23. The primary category is a more restrictive regime that requires most of the Part 23 testing and engineering but limits engine type, weight and performance. CubCrafters officials attending Sun ‘n Fun declined to comment on the new certification, saying it was still an internal discussion. The new certification was approved March 26 and appeared on the FAA website earlier this week.
The primary category was created in the late 1990s to capture simpler, smaller and lower performance aircraft. For conventional aircraft, only four-place or smaller singles with normally aspirated engines weighing less than 2,700 pounds and a stall speed of no more than 61 knots are permitted. Gliders and small helicopters are also eligible. Only a handful of aircraft are registered in the primary category because the certification requirements virtually mirror those for Part 23 and manufacturers almost always use that process.
