Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This proposed AD would require an inspection of the manufacturer's date code on certain electrical relays to identify defective Leach TDH-series electrical relays and replacement of identified relays. This proposed AD results from a report of defective electrical relays affecting emergency equipment. We are proposing this AD to prevent the malfunction of emergency equipment (the passenger oxygen system, the thrust reverse control system, and the auxiliary power unit fire detection, warning, and extinguishing system) during an emergency.