AD FAA-2021-0138

The FAA proposes to adopt a new airworthiness directive (AD) for all BAE Systems (Operations) Limited Model BAe 146 and Model Avro 146-RJ series airplanes. This proposed AD was prompted by a report indicating that during a routine battery capacity check on the emergency light power units, the printed circuit boards (PCBs) for certain power units were found to show signs of burning. This proposed AD would require replacing each Honeywell emergency light power unit having a certain part number with a serviceable emergency light power unit. The FAA is proposing this AD to address the unsafe condition on these products.