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:
Several cases have been reported where the pilot, co-pilot or observer utility light system has failed, resulting in a burning smell within the cockpit. An investigation has revealed that, due to the orientation and location of the carbon molded potentiometers used to control the intensity of the light, the potentiometers can fail and overheat in such a way that burning of the ceiling panel and the associated insulation blanket could occur. This could lead to the presence of smoke in the cockpit, requiring that the pilots carry out the appropriate emergency procedure.
The proposed AD would require actions that are intended to address theunsafe condition described in the MCAI.