SAIB CE-03-36 —

No. CE-03-36 May 14, 2003 We post SAIBs on the internet at www.airweb.faa.gov This is information only. Recommendations are not mandatory.

Introduction This Special Airworthiness Information Bulletin (SAIB) advises you, owners and operators of deHavilland Inc (Bombardier) DHC-2 Mk. I aircraft, of safety information related to the exhaust collector ring segments. Transport Canada Civil Aviation (TCCA) has issued Airworthiness Directive (AD) CF-2002-49, dated December 6, 2002, which requires inspection of the exhaust collector ring segments to detect breaks, cracks or burnt holes. TCCA AD CF-2002-49 supersedes TCCA AD CF-65-3, issued on December 31, 1965, and provides relief for the inspection interval based on field reports.

Background TCCA AD CF-2002-49 concerns the inspection of exhaust collector ring segments. TCCA issued AD CF-65-3 based on a reported event of carburetor fire caused by hot air leaking from the exhaust collector ring segments in the vicinity of the carburetor. They determined that the exhaust collector ring segments may have been inadequately weld-repaired. Since issuance of TCCA AD CF-65-3, there have been no further reported events of carburetor fire caused by leaking exhaust collector ring segments. TCCA has superseded AD CF-65-3, substantiated by field inspection data, and revised the repetitive inspection interval for repaired exhaust collector ring segments from 50 flight hours to 150 flight hours.

Recommendations We recommend that operators of the Bombardier DHC-2 Mk. I aircraft perform inspections of the exhaust collector ring segments as follows:

1. Remove the carburetor heater muff, Part Number (P/N) C2-EE-181A, -161A, -171A, and –1155A, and inspect the exhaust collector ring segments, P/N C2-EE251A, -253A, -255A, and –257A, for cracks, breaks or burnt holes. 2. Replace segments that have developed major breaks, cracks, or burning. 3. Segments with minor cracks must either be replaced or repaired by welding as per DHC-2 Beaver Maintenance Manual Paragraph 5.4.3 and DHC-2 Beaver Repair Manual Paragraph 6-13. 4. Replace segments that have developed further cracking at previous repair weld locations.

Repeat the above inspection at intervals not exceeding 150 flight hours. 1

NOTE: We urge you to report any damage found to the Manager, New York Aircraft Certification Office (NYACO).

For DHC-2 Maintenance Manual/Repair Manual Copies Contact: Action Centre, Bombardier Aerospace, 123 Garratt Blvd., Downsview, Ontario, Canada M3K 1Y5, Phone:(416) 375-4000;Fax:(416) 375-4539; Email: [email protected]

For Further Information Contact: FAA, Sarbhpreet S. Sawhney, NYACO, ANE-172, 10 Fifth Street, Valley Stream, NY 11581-1200; Tel: (516) 256-4225; Fax: (516) 568-2716; email: [email protected] 2