What was found
AFTER CRUISING FOR 40 MINUTES AND A REDUCED POWER DESCENT, WHEN PL`S RETARTED TO FLIGHT IDLE, COCKPIT FILLED WITH BLUE SMOKE THROUGH GASPER VENTS,CREW DONNED O2 MASK, SMOKE DISSAPATED, INFO TO MAINT, NO UNUSAL SMELL OF SMOKE WAS EVER NOTED ON THE GROUND DURING TAXI. R & R NR1 ENGINE IAW WC EX-ATR-72-RAI-001 OPTS CK GOOD, LEAK CHECK GOOD.