Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: "Transport Canada has received numerous service difficulty reports concerning Viking DHC-7 and Bombardier DHC-8 aircraft fluorescent lamp holder damage due to overheating. It has been determined that lamp holder overheating is a result of arcing between the fluorescent tube pins and the lamp holder contacts when the tube is not properly seated during installation.
Overheating of lamp holders, if not corrected, could generate fumes and smoke.'' The unsafe condition could result in an in-flight fire. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.