Safety Alerts
2009-04-25TruTrak autopilot servo arm
 Following some incidents where the screw securing the servo arm on some TruTrak servos has come loose, or even fallen out, TruTrak have now issued a Service Bulletin
2009-05-04Zenith Grounding
 

NTSB Asks FAA To Immediately Ground Zodiac CH-601XL Aircraft.
In an unusual move on Tuesday, the NTSB issued an "urgent safety recommendation" asking the FAA to prohibit further flight of the Zodiac CH-601XL, which has been involved in six in-flight structural breakups since 2006. The board cited four accidents in the U.S. and two in Europe in which a CH-601XL broke up in flight, killing a total of 10 people. According to the NTSB, there is a problem with the airplane design that makes it susceptible to aerodynamic flutter -- a phenomenon in which the control surfaces of the airplane can suddenly vibrate, and if unmitigated, can lead to catastrophic structural failure. The NTSB wants the U.S. fleet grounded until the FAA can determine that the problem has been solved. "The NTSB does not often recommend that all airplanes of a particular type be prohibited from further flight," said NTSB Acting Chairman Mark Rosenker. "In this case, we believe such action will save lives. Unless the safety issues with this particular Zodiac model are addressed, we are likely to see more accidents in which pilots and passengers are killed in airplanes that they believed were safe to fly."

The NTSB also found the stick force gradient was not uniform, and was lesser at high Gs, which could make the airplane susceptible to over-control by the pilot, which could lead to over-stressing the design limits and result in in-flight structural failure. The board also made several requests of ASTM International, the entity that provides the design standards for light sport aircraft. The NTSB says ASTM should add requirements to ensure the standards for LSAs reduce the potential for aerodynamic flutter to occur, develop standards on stick-force characteristics that minimize the possibility inadvertent over-controlling by the pilot, and ensure standards for LSAs result in accurate airspeed indications and appropriate documentation in new airplane pilot operating handbooks. For more details, click here for the full text of the NTSB's safety recommendation letter (PDF) and click here for the NTSB letter to the ASTM (PDF).

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2009-05-15Zenith Grounding
 

14th May 2009 - CASA has now issued an AWB concerning this aircraft

2009-05-31Zenith Grounding
 Zenair Europe has posted a press release about the Ground Vibration Testing that are being done for the German DAeC.
Seems like the 601XL is not prone to flutter after all.
2009-11-11Zenith news from the EAA
 New Zodiac In-Flight Break-up Shows FAA/NTSB Rift
By Glenn Pew, Contributing Editor, Video Editor

Thursday, the FAA froze the issuance of new airworthiness certificates for Zodiac CH-601XL series aircraft; Friday the NTSB released news of another Zodiac in-flight break-up and made an example of its earlier recommendations to the FAA. The FAA\'s most recent action forces operators seeking airworthiness certificates for the model to prove they\'ve made specific modifications meant to prevent aerodynamic flutter.
A Special Airworthiness Information Bulletin issued on November 7 by the FAA already effectively grounded some of the aircraft that were not in compliance -- and there\'s the catch. The Zodiac is available as a Light Sport Aircraft and an Experimental category amateur-built kit. So far, the FAA\'s actions do not require that modifications be made to the amateur-built planes.
The aircraft involved in the most recent (November 6) fatal crash was amateur-built.
In reviewing that accident, the NTSB noted recommendations it had previously sent to the FAA that, had they been implemented, may have prevented the latest fatal crash.The NTSB stated Friday in an advisory that it called on the FAA in April of 2009 to ground the model, citing six accidents involving aerodynamic flutter that had so far killed ten. The Board says that the FAA responded at that time by saying it lacked \"adequate justification\" to impose a mandatory grounding of the entire fleet. Mandatory grounding aside, Zenith (manufacturer of the aircraft kits), the FAA and the EAA have all recommended that all Zodiac CH-650 and CH-601XL aircraft remain grounded until modified, regardless of their certification status.
2009-08-24URGENT AIRWORTHINESS DIRECTIVE – TCM 520/550
 The FAA has issued an AD affecting cylinder assemblies manufactured by Superior Air Parts (SAP) fitted to TCM 520 and 550 series engines. There are roughly 980 aircraft on the Australian register fitted with TCM 520 and 550 series engines. Of those engines is not possible to determine how many are fitted with SAP cylinders, so it would be impossible to get in touch with every one likely to be affected. But the effect could be severe!
The AD requires:
- A check to confirm whether certain cylinder assemblies are fitted. If the cylinder assemblies have more than 750 flight hours, then an initial leak check is required within 25 flight hours and repeat inspections every 50 flight hours.
- Prohibition of installation of such cylinders and the removal of said cylinders when they reach the engine TBO.
The FAA AD becomes effective 9 September 2009 and CASA has agreed to make the Australian AD effective on 24 Sep, so there is some lead time.
Check out the forum for the correct link to the AD.