What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
During terminaiton of simulated autorotaiton tail boom support bracket failed. At attach bolt hole. Damaged rotors. (.4)during a demonstration of an autorotation, the helicopter landed hard. The pilot reported that during the autorotation, after completing a flare, he added 'max' allowable power to initiate a power recovery and directional control was lost. Subsequently, the helicopter landed with a slight yaw. The passenger reported that during the autorotation the pilot stated that 'the spot we would land was visible basically right above the pedals.' The aircraft touched down 'firm,' approximately 90 degrees from the direction of travel. Examination of the helicopter revealed that the tailboom forward attachment fitting was fractured. Both tail rotor blades were attached to the hub and fork; however, one blade was found fractured and separated in the spar root area at the end of the hub spindle, and there was a dent in the leading edge near the tip. The tail rotor drive shaft was found twisted and disengaged from the upper pulley aft drive adapter. Examination of the tailboom forward attachment fitting, p/n:269A2323, and associated parts found that the fracture surface was 'consistent with an overstress failure.' There were 'no signs of preexisting cracks found.' (-23) on may 20, 1998, at approximately 17:30 local time, a Schweizer model 269C helicopter, N41TH, was substantially damaged during a simulated autorotational landing to an open field aproximately six miles west of San Angelo, mathis field. The commercial pilot and one passenger were not injured. The pilot reported that the tail boom forward fitting failed during recoveryfrom the autorotation before the tail rotor struck the ground.
As the FAA filed it
DURING TERMINAITON OF SIMULATED AUTOROTAITON TAIL BOOM SUPPORT BRACKET FAILED. AT ATTACH BOLT HOLE. DAMAGED ROTORS. (.4)DURING A DEMONSTRATION OF AN AUTOROTATION, THE HELICOPTER LANDED HARD. THE PILOT REPORTED THAT DURING THE AUTOROTATION, AFTER COMPLETING A FLARE, HE ADDED 'MAX' ALLOWABLE POWER TO INITIATE A POWER RECOVERY AND DIRECTIONAL CONTROL WAS LOST. SUBSEQUENTLY, THE HELICOPTER LANDED WITH A SLIGHT YAW. THE PASSENGER REPORTED THAT DURING THE AUTOROTATION THE PILOT STATED THAT 'THE SPOT WE WOULD LAND WAS VISIBLE BASICALLY RIGHT ABOVE THE PEDALS.' THE AIRCRAFT TOUCHED DOWN 'FIRM,' APPROXIMATELY 90 DEGREES FROM THE DIRECTION OF TRAVEL. EXAMINATION OF THE HELICOPTER REVEALED THAT THE TAILBOOM FORWARD ATTACHMENT FITTING WAS FRACTURED. BOTH TAIL ROTOR BLADES WERE ATTACHED TO THE HUB AND FORK; HOWEVER, ONE BLADE WAS FOUND FRACTURED AND SEPARATED IN THE SPAR ROOT AREA AT THE END OF THE HUB SPINDLE, AND THERE WAS A DENT IN THE LEADING EDGE NEAR THE TIP. THE TAIL ROTOR DRIVE SHAFT WAS FOUND TWISTED AND DISENGAGED FROM THE UPPER PULLEY AFT DRIVE ADAPTER. EXAMINATION OF THE TAILBOOM FORWARD ATTACHMENT FITTING, P/N:269A2323, AND ASSOCIATED PARTS FOUND THAT THE FRACTURE SURFACE WAS 'CONSISTENT WITH AN OVERSTRESS FAILURE.' THERE WERE 'NO SIGNS OF PREEXISTING CRACKS FOUND.' (-23) ON MAY 20, 1998, AT APPROXIMATELY 17:30 LOCAL TIME, A SCHWEIZER MODEL 269C HELICOPTER, N41TH, WAS SUBSTANTIALLY DAMAGED DURING A SIMULATED AUTOROTATIONAL LANDING TO AN OPEN FIELD APROXIMATELY SIX MILES WEST OF SAN ANGELO, MATHIS FIELD. THE COMMERCIAL PILOT AND ONE PASSENGER WERE NOT INJURED. THE PILOT REPORTED THAT THE TAIL BOOM FORWARD FITTING FAILED DURING RECOVERYFROM THE AUTOROTATION BEFORE THE TAIL ROTOR STRUCK THE GROUND.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.