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:
One operator experienced failures of four Fuel Level Sensor- Amplifier (FLSA) and Multi Tank Indicators (MTI) units. FLSA and MTI failures have been identified as having been caused by incorrect connector sleeves material fitted to the MTI units.
Degradation of the electrical insulation sleeves of the Low- level indication lamps on the MTI on the flight deck can cause a short circuit that might result in high voltage being conveyed to the high- and low-level sensors in the outer tanks. This might cause the level sensor to heat above acceptable limits. * * * * *
This action is necessary to prevent overheating of the fuel level sensors, which could result in a fuel tank explosion and consequent loss of the airplane. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.