What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Snapping sound on approach. Lost tailrotor control. Auto rotated hard ldg. Sread skids. Chopped tail broke shaft. (.4) the helicopter experienced a tail rotor drive shaft failure while on final approach to landing. Approximately 45 to 50 feet AGL, the pilot heard a 'loud snapping sound,' which was followed by a 'loss of tail rotor control.' An autorotation was initiated, and subsequently, the helicopter landed 'hard' on the grassy staging field and came to a stop upright. Examination of the helicopter revealed that two of the tail rotor drive shaft segments were fractured. Additionally, one of the two bolts connecting the aft end of one of the fractured segments to a disc coupling (thomas coupling) was missing. The missing bolt was not recovered, although a nut and two beveled washers were found on top of the tail boom beneath the driveshaft. An examination of the remaining bolt revealed that it exhibited fretting, wear and deformation to only the last two and one-half threads. Review of the maintenance records revealed no entries indicating that any of the tail rotor drive shaft segments were removed in the two years preceding the accident. (-23) on June 7, 1998, at approximately 5:45 pm, a Bell 206B, owned and operated by houston helicopters inc. an on-demand FAR part 135 operator (yhha), made a hard landing during an approach to land at a temporary helicopter landing site. This flight was a revenue flight for oversight of a boat race in the immediate area. There were three passengers aboard for this segment. VFR conditions prevailed during this flight and no flight plan was filed. The aircraft sustained damage to both left and right hand skids and buckling to the tail boom upon impat with the ground, but; it appears that damage to the tail rotor drive shaft and sheet metal damage to the tail boom occurred prior to the ground impact. The pilot and passengers were not injured before or after the ground impact. The pilot in command was a Mr. Rodney alan moore, certificate #265155463. This flight originated from the same site that his accident had occurred at approximately 4:46 of the same date. This office is continuing the investigation of this accident for possible mechanicl malfunctions to the tail rotor system.
As the FAA filed it
SNAPPING SOUND ON APPROACH. LOST TAILROTOR CONTROL. AUTO ROTATED HARD LDG. SREAD SKIDS. CHOPPED TAIL BROKE SHAFT. (.4) THE HELICOPTER EXPERIENCED A TAIL ROTOR DRIVE SHAFT FAILURE WHILE ON FINAL APPROACH TO LANDING. APPROXIMATELY 45 TO 50 FEET AGL, THE PILOT HEARD A 'LOUD SNAPPING SOUND,' WHICH WAS FOLLOWED BY A 'LOSS OF TAIL ROTOR CONTROL.' AN AUTOROTATION WAS INITIATED, AND SUBSEQUENTLY, THE HELICOPTER LANDED 'HARD' ON THE GRASSY STAGING FIELD AND CAME TO A STOP UPRIGHT. EXAMINATION OF THE HELICOPTER REVEALED THAT TWO OF THE TAIL ROTOR DRIVE SHAFT SEGMENTS WERE FRACTURED. ADDITIONALLY, ONE OF THE TWO BOLTS CONNECTING THE AFT END OF ONE OF THE FRACTURED SEGMENTS TO A DISC COUPLING (THOMAS COUPLING) WAS MISSING. THE MISSING BOLT WAS NOT RECOVERED, ALTHOUGH A NUT AND TWO BEVELED WASHERS WERE FOUND ON TOP OF THE TAIL BOOM BENEATH THE DRIVESHAFT. AN EXAMINATION OF THE REMAINING BOLT REVEALED THAT IT EXHIBITED FRETTING, WEAR AND DEFORMATION TO ONLY THE LAST TWO AND ONE-HALF THREADS. REVIEW OF THE MAINTENANCE RECORDS REVEALED NO ENTRIES INDICATING THAT ANY OF THE TAIL ROTOR DRIVE SHAFT SEGMENTS WERE REMOVED IN THE TWO YEARS PRECEDING THE ACCIDENT. (-23) ON JUNE 7, 1998, AT APPROXIMATELY 5:45 PM, A BELL 206B, OWNED AND OPERATED BY HOUSTON HELICOPTERS INC. AN ON-DEMAND FAR PART 135 OPERATOR (YHHA), MADE A HARD LANDING DURING AN APPROACH TO LAND AT A TEMPORARY HELICOPTER LANDING SITE. THIS FLIGHT WAS A REVENUE FLIGHT FOR OVERSIGHT OF A BOAT RACE IN THE IMMEDIATE AREA. THERE WERE THREE PASSENGERS ABOARD FOR THIS SEGMENT. VFR CONDITIONS PREVAILED DURING THIS FLIGHT AND NO FLIGHT PLAN WAS FILED. THE AIRCRAFT SUSTAINED DAMAGE TO BOTH LEFT AND RIGHT HAND SKIDS AND BUCKLING TO THE TAIL BOOM UPON IMPAT WITH THE GROUND, BUT; IT APPEARS THAT DAMAGE TO THE TAIL ROTOR DRIVE SHAFT AND SHEET METAL DAMAGE TO THE TAIL BOOM OCCURRED PRIOR TO THE GROUND IMPACT. THE PILOT AND PASSENGERS WERE NOT INJURED BEFORE OR AFTER THE GROUND IMPACT. THE PILOT IN COMMAND WAS A MR. RODNEY ALAN MOORE, CERTIFICATE #265155463. THIS FLIGHT ORIGINATED FROM THE SAME SITE THAT HIS ACCIDENT HAD OCCURRED AT APPROXIMATELY 4:46 OF THE SAME DATE. THIS OFFICE IS CONTINUING THE INVESTIGATION OF THIS ACCIDENT FOR POSSIBLE MECHANICL MALFUNCTIONS TO THE TAIL ROTOR SYSTEM.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.
Other reports on N16814 · 2
Matched to the same aircraft by N-number and date.