Zenith responds to airworthiness freeze

zodiacThe fatal crash of a homebuilt Zodiac CH-601XL last month has prompted the FAA to freeze the issuance of new airworthiness certificates for the design. The accident was the sixth attributed to an in-flight break up.

The timing of the crash is poignant, as it came one day before the FAA issued a Special Airworthiness Information Bulletin concerning aerodynamic flutter that may have been a factor in the accidents.

“There have been too many crashes. We think one crash is too many,” said Sebastien Heintz, president of Zenith Aircraft, which manufactures the kits. His father, Chris Heintz, is the designer of the aircraft. “The frustrating thing is that there is no single cause that was responsible for all the accidents.”

On Nov. 6, a Zodiac CH-601XL was destroyed as a result of an in-flight breakup near Agnos, Arkansas, killing the pilot. Both wings separated from the fuselage in-flight.

In April, the NTSB called on the FAA to ground all Zodiac CH-601XLs after it linked six accidents, which killed 10 people, to aerodynamic flutter, a phenomenon in which the control surfaces and wings can suddenly oscillate and lead to catastrophic structural failure. Preliminary investigation of the Arkansas accident reveals a failure mode similar to that seen in the earlier crashes, NTSB officials report.

Since April, the NTSB and the FAA have been conducting a special review of the Zodiac CH601XL and the similarly designed CH650 to evaluate design and operational details of the aircraft. The SAIB is the result of that review.

Heintz noted his company is working closely with the FAA and the NTSB on the issue.

“We are taking a very pro-active approach in that we have introduced a full upgrade package,” he said. “It beefs up the entire airplane.”

As this issue was going to press, the company was in the process of finalizing the upgrade package.

“We are making the upgrade package available to all builders and owners to meet the FAA’s recommendations as soon as possible and at minimum inconvenience and cost,” said Heintz. “We think it will cost about $400, which is fairly inexpensive.”

According to Heintz, the package is designed to strengthen the airplane by over-building the wing spars and adding aileron counter-balance.

“We strongly believe that implementation of the comprehensive upgrade package kit, combined with continuing pilot education and training, as well as an ongoing airworthiness/maintenance program, will put an end to the type of tragic accidents that have been happening and restore this aircraft’s reputation as a capable and fun Light Sport Aircraft,” he said.

Heintz estimates the upgrade package will take a few weeks to a few months for aircraft owners to apply — “depending on how much they work on their airplanes,” he said.

Heintz noted that within hours of the SAIB being issued the company had information posted on its website to answer customer’s questions.

“We have also been taking a lot of phone calls,” he said. “We have customers around the world and we have been here for them. We are talking to them and they have been very supportive.”

For more information: ZenithAir.com, Newplane.com, FAA.gov.


  1. Younis Forsyth says

    I own a factory built Zodiac 650. The untold story seems to be how this is affecting the Zodiac SLSA Owners.

    The modification kit for the homebuilders is $352. The homebuilders if willing and able can make these modifications themselves.

    Although I am a Light Sport Repairman Maintenance – Airplane, due to the wording of the Safety Alert I am not authorized to make these modifications. Nor am I authorized to complete the inspection in order to obtain a ferry permit.

    The factory upgrade will cost owners approximately $5,750 for about 100-120 hours of labor. The last I heard from the factory, they had said they hope to be able to repair approximately 3-4 aircraft a month. The quotes that I received for this modification in my area are approaching $8,500, plus the cost of the kit. If I am unable to get a ferry permit, then I would also incur the cost of trucking the aircraft somewhere.

    While Zenith is responsive to the home-builders, as an SLSA owner I must contact the factory. I personally have found it difficult to get in touch with the factory. Although yesterday when I called the factory, the phones were forwarded and being answered by a company in Florida.

    While my misfortune pales in comparison to the loss of life, it has created a major financial impact.

  2. Roger Lambert says

    There are numerous qualified AP’s and IA’s advertising their availibility to do this modification with costs from $2500 to $4500.
    The operating limitations on the airplane remain unchanged pursuant to the latest drawings of 12/9/09.

  3. Steve Wiley says

    This is a joke. The SAIB requires SLSA owners to comply. Not homebuilders, although they surely will. SLSA owners did not build their airplanes, and in almost every circumstance are not qualified nor certified to conduct this upgrade work. After watching the videos that Zenith is producting as they conduct this upgrade on their factory demonstrator – one thing is clear: this is a very labor intensive upgrade. It could cost north of $10,000 for an FAA certified repairman to effect this upgrade on an SLSA – if you can even find one willing to do the work for fear of getting caught up in a lawsuit later should anything go awry. After this upgrade is complete, the operating limitations of the airplane will be significantly altered. Lower VNE, Va, payload, etc.

    This is an unmitigated disaster for anyone owning an SLSA version of this airplane. I would expect a publication like GA News to do more than gloss over the issue with little more than hot air statements from the company owners.

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