As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TIP CAP REMOVED FROM SIKORSKY OTR. INSTALLED ON BLUE BLADE. AIRCRAFT FLOWN ABOUT 1.50 HOURS. CREW HEARD 'BANG' FOLLOWED BY HEAVY VIBRATION. LANDED, FOUND AFT ONE-THIRD OF TIP CAP MISSING. NO INDICATION OF HAVING STRUCK ANYTHING. SUBMITTER STATED THIS CAP HAD BEEN TAKEN OFF AND REPLACED AT LEAST THREE TIMES FOR PAINT AND FILLER PROBLEMS.