What was found
DURING BOARDING A BUNCH OF SMOKE CAME INTO CABIN & FLIGHT DECK. APU FAIL CAUTION SHORTLY AFTER & IT SHUT ITSELF DOWN. APU WAS RUNNING WHEN ARRIVED AT AIRCRAFT. C/A: C/W WORKSCOPE, REF NRWC 905-ORD-05100,905-ORD-05101,AND 905-ORD-05104 REF NRWC 905-ORD-05098 FOR APU RAR, OPERATIONS CHECK LEAK CHECK GOOD. NO SMOKE OR ORDER NOTED IN CABIN OR FLIGHT DECK AT THIS TIME END.