FAA: No Decision to Ground Zodiac CH-601XL
April 15, 2009 — The FAA has not grounded the Zodiac CH-601XL aircraft despite a request by the National Transportation Safety Board (NTSB) to do so, according to a spokesman from the agency. The NTSB issued an urgent safety recommendation asking for the action citing six in-flight structural breakups since 2006. In a news release Tuesday, the NTSB says it suspects “aerodynamic flutter” as the cause of all the accidents, which resulted in 10 fatalities.
“We have just received the Board’s recommendation and have made no final determination on a course of action,” said FAA spokesman Les Dorr. The FAA recently formed a team of experts to look into possible design or manufacturing issues with the Zodiac CH601. Although the in-flight breakups are of particular concern, the agency also intends to focus on other factors, such as construction and maintenance of the experimental amateur-built versions of this design.
“The team will examine all existing variants, despite the current NTSB focus that appears to be primarily on the light-sport version,” Dorr added. “We plan to work with NTSB, British and Dutch accident investigators on the review of the Zodiac’s design characteristics and the data substantiating the NTSB's recommended grounding of the airplane.”
Matthew Heintz, manager of Zenair in Canada, said the company is in the process of evaluating the NTSB report, but expressed confidence in the aircraft’s design.
“We absolutely do have confidence in the aircraft,” he said, adding that over the past several weeks, two independent firms - one in the U.S. and the other in Germany - have been conducting flutter analyses on the design. So far no aerodynamic flutter has been found, he said, and the company expects to have the final reports made available on the Zenair website when completed.
Heintz noted that an exhaustive two-year investigation into one of the fatal crashes – which occurred November 2006 in Yuba City, California – mentioned nothing about aerodynamic flutter as causing the accident.
“If there is something wrong with the design, we want to fix it,” Heintz said. Company-issued service bulletins have instructed owners to inspect all control cables and adjust as necessary so that they are within the prescribed parameters.
Zenair no longer manufactures the CH-601XL, as the largely similar CH-650 special light-sport aircraft has replaced that model.
Insurance availability for the airplanes has not changed, according to Bob Mackey, Falcon Insurance Agency’s representative for the EAA Aircraft Insurance Plan. “It’s not a problem. Insurance continues to be available for the airplane with no impact or detriment to the underwriting,” he said. “The industry is taking a wait-and-see approach.”