In-flight Break Ups Continue To Draw International Attention

Australia's Civil Aviation Safety Authority, Thursday, issued an updated AWB on the Zenair CH 601XL, in response to the number of accidents reported over the past few years as well as the increased scrutiny brought to the aircraft by the NTSB.

1. Applicability: All Zenair Zodiac CH 601XL (ULM and amateur built/experimental models).

2. Purpose: The purpose of this bulletin is to advise the owners, operators and maintainers of any Zodiac CH 601XL aircraft to check the manufacturer’s current listing of continuing airworthiness documents for their aircraft and to maintain their aircraft to the most recent maintenance data.

3. Background: There have been four accidents in the United States and two in Europe in which a CH 601XL broke-up in flight killing the occupants on board. The National Transport Safety Board (NTSB) has investigated the US accidents and cited flutter as a possible cause. The details of the investigation and Safety Recommendations can be found in NTSB Safety Recommendations A-09-30 (Urgent) through -37.

Zenair Europe has advised the European National Aviation Authorities that they will be conducting comprehensive independently-verified tests to demonstrate that the CH 601XL is airworthy. (Zenair letter dated 26 February, 2009). They have also released Service Bulletin ZE-2008-01 to advise maintainers of the CH 601XL of the need to maintain the appropriate control cable tensions.

4. Recommendations: CASA recommends that all operators and maintainers --

1. Ensure the maintenance data for the Zenair CH 601XL is current and the aircraft is maintained to this data.
2. Ensure that the control cables are maintained to the required tensions.
3. Monitor other sources of in-service information for the CH 601XL aircraft, such as the Recreational Aviation Australia website.

FMI: www.casa.gov.au, AirworthinessBulletin@casa.gov.au