Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all EMBRAER Model ERJ 170-100 LR, -100 STD, -100 SE, and -100 SU airplanes. The existing AD currently requires repetitively replacing the low-stage check valve and associated seals of the right-hand engine bleed system. This proposed AD adds new airplanes to that existing requirement. For all airplanes, this proposed AD would also require repetitively replacing the low-stage check valve and associated seals of the left-hand engine bleed system with a new check valve and new seals. This proposed AD results from a report that an engine shut down during flight due to the failure of the low-stage check valve to close. We are proposing this AD to prevent failure of the low-stage check valve, which could result in an engine shutting down during flight.