When the NTSB last week issued a report calling for the Zodiac CH-601XL aircraft to be immediately grounded due to concerns about aerodynamic flutter, it caught the manufacturers by surprise This week at Sun ‘n Fun, Mathieu Heintz of Zenair provided AVweb with an update on the company’s response to the concerns raised by the report. Independent researchers in Germany are conducting detailed tests on the airplane wings to explore any possibility of flutter issues, Heintz said. “We’ve seen very clearly that when we have tight control cables as per the design requirements, we do not have a flutter problem with the airplane,” he said. Loose cables can result in flutter, he said, but proper maintenance should prevent that from happening. Many of the CH-601XL aircraft were sold as kits before the S-LSA version became available. Heintz said that videos and other data and reports from the independent testing now underway will soon be made available on the company’s Web site, and he added that he met with FAA representatives at Sun ‘n Fun this week. Click here to listen to AVweb‘s podcast of the full interview with Heintz.
The CH-601XL airplane is sold in a kit version by Zenith Aircraft, which is run by Sebastian Heintz, and is also sold as an S-LSA by AMD (Aircraft Manufacturing & Design). The CH-601XL was certified as an S-LSA in 2005. In the six accidents cited by the NTSB, two of the aircraft were experimental amateur-built (one in California and one in Utah), one in California was an S-LSA manufactured by AMD, and one in Florida was an S-LSA built by the Czech Aircraft Works. The other two crashes were in the Netherlands and in Spain. Click here for AVweb‘s report on the NTSB recommendation, and click here for the initial response from the FAA and the industry.