As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SYR-FLT 3863, UPON APPROACH AS POWER REDUCED TO IDLE, THE COCKPIT STARTED TO FILL WITH SMOKE. CREW DONNED O2 MASKS, DECLARED EMERGENCY AND LANDED SAFELY. MAINTENANCE INSPECTED AND FOUND THE NR 1 ENGINE AIR SWITCHING VALVE AT FAULT. REMOVED, CLEANED AND REINSTALLED VALVE. GROUND ENGINE RUN PROVED SATISFACTORY.