Narrative:

Departed elevated hospital pad on an inter-hospital xfer with a patient and 3 medical crew aboard. Landed at destination, medical center emergency room pad and completed left side 'hot off load' (engines at ground idle, rotors turning) of patient and 2 crew. Following off load, departed emergency room pad with 1 medical crew and repositioned to hangar pad located on hospital grounds. Upon shutdown and exit from cockpit, noticed the right vertical fin missing from the aircraft. 'Grounded' aircraft via logbook write-up and notified the company. Company then promptly notified FAA/NTSB. Prior to the outbound leg, I completed a preflight inspection and a before first flight inspection was completed by company mechanic with all appropriate logbook entries. En route flight time to pick up hospital was 30 mins where a complete shutdown was completed. I completed a through-flight, walkaround inspection of aircraft and accompanied the medical crew into the hospital to assist with patient movement. Upon returning to aircraft, the patient was loaded by the crew on the left side while I entered the cockpit on the right side. Run-up, takeoff and the entire return leg was uneventful. Subsequent preliminary inspection of horizontal stabilizer at vertical fin attaching point indicated bolts likely cracked and sheared due to vibration fatigue. Although all required daily and preflight inspections were performed, I would feel better about the incident if I had conducted a more hands-on through-flight inspection, physically touching all cowlings, fins, antennae, etc. Although highly unlikely that any play or movement could have been felt, as a pilot, I would know I had done everything within reason to ensure the aircraft was airworthy. The fin has not been located so when it departed is unknown. Because of the short distance from the emergency room pad to the hangar it can be reasonably assumed the fin departed prior to the first landing. The industry standard of 'hot off loads' with the rotors turning requires the pilot to remain on the controls. Because this is a single pilot operation and the off load was on the left side, no one had the opportunity to notice the missing fin prior to the repos flight. The fins are located toward the rear and not visible from the cockpit. Requiring shutdown at every landing point could prevent further incident. Callback conversation with reporter revealed the following information: reporter stated that the manufacturer has idented the cause of the problem as the vertical fin attach bolt and that a service bulletin has been issued to remove and replace the bolts with a new type of bolt at the next scheduled inspection. Reporter advised that this helicopter was only a few hours from the next inspection when the incident occurred. Reporter advised that the loss of the vertical fin has no affect on normal flight and is only used for additional stability in the event of a loss of tail rotor thrust. Reporter stated that the fin was located in a private yard and no damage resulted.

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Original NASA ASRS Text

Title: S65C PLT DETECTS APPARENT INFLT LOSS OF R VERT FIN AFTER COMPLETION OF FLT.

Narrative: DEPARTED ELEVATED HOSPITAL PAD ON AN INTER-HOSPITAL XFER WITH A PATIENT AND 3 MEDICAL CREW ABOARD. LANDED AT DEST, MEDICAL CTR EMER ROOM PAD AND COMPLETED L SIDE 'HOT OFF LOAD' (ENGS AT GND IDLE, ROTORS TURNING) OF PATIENT AND 2 CREW. FOLLOWING OFF LOAD, DEPARTED EMER ROOM PAD WITH 1 MEDICAL CREW AND REPOSITIONED TO HANGAR PAD LOCATED ON HOSPITAL GNDS. UPON SHUTDOWN AND EXIT FROM COCKPIT, NOTICED THE R VERT FIN MISSING FROM THE ACFT. 'GNDED' ACFT VIA LOGBOOK WRITE-UP AND NOTIFIED THE COMPANY. COMPANY THEN PROMPTLY NOTIFIED FAA/NTSB. PRIOR TO THE OUTBOUND LEG, I COMPLETED A PREFLT INSPECTION AND A BEFORE FIRST FLT INSPECTION WAS COMPLETED BY COMPANY MECH WITH ALL APPROPRIATE LOGBOOK ENTRIES. ENRTE FLT TIME TO PICK UP HOSPITAL WAS 30 MINS WHERE A COMPLETE SHUTDOWN WAS COMPLETED. I COMPLETED A THROUGH-FLT, WALKAROUND INSPECTION OF ACFT AND ACCOMPANIED THE MEDICAL CREW INTO THE HOSPITAL TO ASSIST WITH PATIENT MOVEMENT. UPON RETURNING TO ACFT, THE PATIENT WAS LOADED BY THE CREW ON THE L SIDE WHILE I ENTERED THE COCKPIT ON THE R SIDE. RUN-UP, TKOF AND THE ENTIRE RETURN LEG WAS UNEVENTFUL. SUBSEQUENT PRELIMINARY INSPECTION OF HORIZ STABILIZER AT VERT FIN ATTACHING POINT INDICATED BOLTS LIKELY CRACKED AND SHEARED DUE TO VIBRATION FATIGUE. ALTHOUGH ALL REQUIRED DAILY AND PREFLT INSPECTIONS WERE PERFORMED, I WOULD FEEL BETTER ABOUT THE INCIDENT IF I HAD CONDUCTED A MORE HANDS-ON THROUGH-FLT INSPECTION, PHYSICALLY TOUCHING ALL COWLINGS, FINS, ANTENNAE, ETC. ALTHOUGH HIGHLY UNLIKELY THAT ANY PLAY OR MOVEMENT COULD HAVE BEEN FELT, AS A PLT, I WOULD KNOW I HAD DONE EVERYTHING WITHIN REASON TO ENSURE THE ACFT WAS AIRWORTHY. THE FIN HAS NOT BEEN LOCATED SO WHEN IT DEPARTED IS UNKNOWN. BECAUSE OF THE SHORT DISTANCE FROM THE EMER ROOM PAD TO THE HANGAR IT CAN BE REASONABLY ASSUMED THE FIN DEPARTED PRIOR TO THE FIRST LNDG. THE INDUSTRY STANDARD OF 'HOT OFF LOADS' WITH THE ROTORS TURNING REQUIRES THE PLT TO REMAIN ON THE CTLS. BECAUSE THIS IS A SINGLE PLT OP AND THE OFF LOAD WAS ON THE L SIDE, NO ONE HAD THE OPPORTUNITY TO NOTICE THE MISSING FIN PRIOR TO THE REPOS FLT. THE FINS ARE LOCATED TOWARD THE REAR AND NOT VISIBLE FROM THE COCKPIT. REQUIRING SHUTDOWN AT EVERY LNDG POINT COULD PREVENT FURTHER INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THE MANUFACTURER HAS IDENTED THE CAUSE OF THE PROB AS THE VERT FIN ATTACH BOLT AND THAT A SVC BULLETIN HAS BEEN ISSUED TO REMOVE AND REPLACE THE BOLTS WITH A NEW TYPE OF BOLT AT THE NEXT SCHEDULED INSPECTION. RPTR ADVISED THAT THIS HELI WAS ONLY A FEW HRS FROM THE NEXT INSPECTION WHEN THE INCIDENT OCCURRED. RPTR ADVISED THAT THE LOSS OF THE VERT FIN HAS NO AFFECT ON NORMAL FLT AND IS ONLY USED FOR ADDITIONAL STABILITY IN THE EVENT OF A LOSS OF TAIL ROTOR THRUST. RPTR STATED THAT THE FIN WAS LOCATED IN A PVT YARD AND NO DAMAGE RESULTED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.