AL 2007-02
19 September 2007
Transport Canada Civil Aviation (TCCA) wish to alert owners, operators and maintenance facilities to the hazardous consequences of defective and/or improper engagement of the Camloc assembly that retain the upper and lower nacelle cowlings to the engine nacelle.
There have been incidents whereby both the upper and lower engine access cowls separated from aircraft during flight. In early 2007, a foreign operator reported a departed upper cowl during flight, which caused impact damage to the LH horizontal stabilizer and the vertical fin fairing. Immediately prior to this event, the cowls had been removed for maintenance accessibility.
A recent SDR from Canadian operator reported a cowl separation (during descent) on the 3rd flight leg following maintenance. The lower cowl ripped free, however, the majority of Camloc fasteners that hold the cowl were still installed in the cowl retainers.
Most of these in-flight cowl departure events occurred following removal and installation of the cowls. Subsequently, a review of cowl attachment design and installation procedure is underway to help alleviate any inherent susceptibility of existing cowl installation to maintenance errors. Additionally, in-flight buffeting may be a factor causing release of the Camloc fasteners from its retaining mechanism.
TCCA also recommend that extra attention be taken to closely examine the studs and grommets for wear and damage and to verify that the Camloc fasteners assemblies are flush with the cowl skin and positively engaged.
In the interim, TCCA recommend compliance with the following manufacturers (Bombardier) recommendations:
Bombardier (BA) Service Bulletins (SB) 601R 71 030, CF34-NAC-71-036
In-Service Activities Report (ISAR) Item No. 2004 07 7110, and
BA Service Letter (SL) RJ-SL-71-006 dated September 7, 2005.
TCCA are currently working with the Type Certificate Holder to develop appropriate corrective action to address the aforementioned safety issues.
Malfunctions, defects or failures occurring on aeronautical products should be reported to Transport Canada, Continuing Airworthiness via the Service Difficulty Reporting Program.
For further information, please contact a Transport Canada Centre, or contact Mr. Barry Caldwell at (613) 952-4358, facsimile (613) 996-9178 or e-mail caldweb@tc.gc.ca.
For Director, Aircraft Certification
B. Goyaniuk
Chief, Continuing Airworthiness
Note: For the electronic version of this document, please consult the following Web address:
https://tc.canada.ca/en/aviation/aircraft-airworthiness/aircraft-certification