What was found
JFK-PIT, STRONG UNKNOWN FUMES IN COCKPIT AND CABIN DURING INITIAL CLIMB. COMPLETED CABIN /SMOKE FUMES QRH AND RETURNED TO JFK. FUMES DISSIPATED INFLIGHT PRIOR TO LANDING. ACCOMPLISHED FIM TASK 21-20-00-810-801-A SMOKE AND /OR ABNORMAL SMELL IN PASSENGER CABIN AND/OR ABNORMAL SELL IN PASSENGER CABIN AND/OR COCKPIT. FOUND FOUL SMELL DURING ENGINE NR 1 OPERATION DUE TO ENGINE NR 1 BIRD INGESTION. ENGINE WAS BORESCOPED AND CLEANED, NO ABNORMALITIES NOTED. PERFORMED ELECTRICAL ODOR INSPECTION PER LTV MM 44-20-10. NO ABNORMALITIES NOTED. LTV OPS NORMAL.