Zodiac: The “Corvair of the Air”


The urgent recommendation of the National Transportation Safety Board (NTSB) this week to ground the fleet of Zodiac CH-601XL Special Light Sport Aircraft was a “heroic” decision that could save lives if the Federal Aviation Administration acts promptly, said Ladd Sanger, a leading air crash litigation attorney.

“The Zodiac is the Corvair of the air,” said Sanger, a licensed commercial pilot and managing partner of the Slack & Davis law firm’s Dallas office. “This is a poorly designed and tested aircraft that poses a danger to anyone who flies in it. The NTSB’s recommendation to ground the fleet is nothing short of heroic. I am not aware of the NTSB ever taking such an extraordinary step as asking the FAA to ‘prohibit further flight’ of a fleet of aircraft. Unfortunately, I am concerned whether the FAA will follow the NTSB’s wise guidance.”

The NTSB issued safety recommendations A-09-30 (urgent) through A-09-37 and A-09-38 through A-09-40 calling for the FAA to “prohibit further flight” of the aircraft until the FAA can determine if it has adequate protection from flutter, an aerodynamic force that can quickly lead to structural failure and subsequent crash. The recommendations included requiring possible design modifications and other industry-wide improvements for the light sport airplanes.

The NTSB recommendations noted that there had been at least six accidents due to flutter with 10 deaths involving the aircraft. This aircraft and others in its category receive a type of FAA certification that does not require that the FAA actually approve the airplane’s design, but relies on the manufacturer’s assertion that it meets industry safety standards.

Sanger said the flutter issue isn’t the only aerodynamic design failure. The Zodiac also has significant design problems with a new canopy design that does not meet FAA standards and, if it comes open in flight, will block the airflow over the horizontal tail resulting in inability to control the aircraft.

“I am currently representing the family of Dennis Levy, who died as a result of injuries he sustained in an August 14, 2008, Zodiac crash near Farmersville, Texas,” said Sanger. “Just two weeks ago I inspected the wreckage of this aircraft and was astounded at the numerous poor design features of the aircraft, some of which do not even meet the minimum FAA standards.

“The aircraft’s designer, Zenith Aircraft, attributes the flutter problem to misadjusted control cables, but my inspection found fundamental aerodynamic deficiencies that go far beyond cable adjustments. It is clear this aircraft was not subjected to the appropriate aerodynamic testing.”

Sanger, who holds FAA instrument and multi-engine ratings and is an aviation attorney who has worked on hundreds of plane crash cases, said this airplane “highlights the best and worst of what I have seen in my career. The Zodiac is perhaps one of the most unairworthy aircraft since the de Havilland Comet which had to be grounded because fatigue cracks from the windows caused in-flight structural failures. On the positive side I am very appreciative of the NTSB for being proactive in recommending grounding of the fleet and can only hope the FAA follows the recommendation.”