What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
FAA iic, inspector gary hendrickson, conducted on scene investigation of the accident aircraft, N724WD. Iic found the aircraft wreckage contained in one location with the exception of some scattered debris within a 50 foot radius of the aircraft. The aircraft was found with engine impacted approximately 6 inches into the ground. The damage to the aircraft indicated that this accident was a high angle, low velocity impact. The left and right leading edges were found rolled under the wing APPROXIMATELY12 inches. Each wings leading edge was found with similar damage consistent with a wings level impact. The rear section of the fuselage had broken away to the right. An inspection of the aircraft found all major components and flight controls at the scene. A continuity check was performed of the flight control system with no defects noted. An inspection of the rudder found the left rudder stop broken and damage noted on the left side of the rudder consistent with contact with the left elevator trim tab. The electric elevator trim system was inspected with the trim actuator removed and tested on the scene. No defect was found with the trim actuator. The trim tab push rod was found damaged at the rod end attached to the actuator. This rod end is plastic. The elevators and rudder was checked for freedom of movement with no defects noted. The electric flap actuator was removed and inspected. The actuator was found in the flaps up position. The left flap was found virtually undamaged and it's control system intact. The right elevator was found virtually undamaged however its pushrod tube was found sheared just above the threaded rod end. An inspection of main wing spar revealed no discrepancies. Inspection of the forward wing tank support bracket was not possible due to impact damage. An inspection of the left rear spar attach point was found intact with evidence that the wing had shifted down, presumed to happened during the impact. An inspection of the right rear spar attach point found the wing rear spar bracket had fractured away from the fuselage attach bracket. Upon removal of the aircraft to a flat bed truck, the right rear spar attach hardware was removed from the fuselage attach bracket for inspection. Portions of the wing rear spar bracket remained in the fuselage attach bracket. Inspection of these pieces found the bracket had failed on both the vertical and horizontal axis. Each failure point originated from the attach bolt hole. Examination of the vertical failure found 45 degree shear lips. Inspection of the horizontal failure found not shear lips raising questions about the integrity of this rear spar. Inspection of the fuselage right rear spar attach brackets found very little damage that would have been consistent with impact damage necessary to cause the failure of the wing rear spar. During a follow up inspection of the aircraft at air transport in phoenix AZ, the wing and fuselage attachment structures were removed for analysis by the NTSB. During reconstruction of the wing spar, it was apparent that the wing spar mounting hole was severely elongated on the horizontal axis. Both the rear wing spar and fuselage attach brackets were sent to the NTSB lab for analysis. An interview with privacy data omitted, the builder's helper, was conducted on December 29. privacy data omitted Did not recall any issues with drilling the rear spar attachment hole during the construction of the aircraft. At this time, the cause of the rear spar failure could not be determined and further data from metallurgic analysis of the spar is pending.
As the FAA filed it
FAA IIC, INSPECTOR GARY HENDRICKSON, CONDUCTED ON SCENE INVESTIGATION OF THE ACCIDENT AIRCRAFT, N724WD. IIC FOUND THE AIRCRAFT WRECKAGE CONTAINED IN ONE LOCATION WITH THE EXCEPTION OF SOME SCATTERED DEBRIS WITHIN A 50 FOOT RADIUS OF THE AIRCRAFT. THE AIRCRAFT WAS FOUND WITH ENGINE IMPACTED APPROXIMATELY 6 INCHES INTO THE GROUND. THE DAMAGE TO THE AIRCRAFT INDICATED THAT THIS ACCIDENT WAS A HIGH ANGLE, LOW VELOCITY IMPACT. THE LEFT AND RIGHT LEADING EDGES WERE FOUND ROLLED UNDER THE WING APPROXIMATELY12 INCHES. EACH WINGS LEADING EDGE WAS FOUND WITH SIMILAR DAMAGE CONSISTENT WITH A WINGS LEVEL IMPACT. THE REAR SECTION OF THE FUSELAGE HAD BROKEN AWAY TO THE RIGHT. AN INSPECTION OF THE AIRCRAFT FOUND ALL MAJOR COMPONENTS AND FLIGHT CONTROLS AT THE SCENE. A CONTINUITY CHECK WAS PERFORMED OF THE FLIGHT CONTROL SYSTEM WITH NO DEFECTS NOTED. AN INSPECTION OF THE RUDDER FOUND THE LEFT RUDDER STOP BROKEN AND DAMAGE NOTED ON THE LEFT SIDE OF THE RUDDER CONSISTENT WITH CONTACT WITH THE LEFT ELEVATOR TRIM TAB. THE ELECTRIC ELEVATOR TRIM SYSTEM WAS INSPECTED WITH THE TRIM ACTUATOR REMOVED AND TESTED ON THE SCENE. NO DEFECT WAS FOUND WITH THE TRIM ACTUATOR. THE TRIM TAB PUSH ROD WAS FOUND DAMAGED AT THE ROD END ATTACHED TO THE ACTUATOR. THIS ROD END IS PLASTIC. THE ELEVATORS AND RUDDER WAS CHECKED FOR FREEDOM OF MOVEMENT WITH NO DEFECTS NOTED. THE ELECTRIC FLAP ACTUATOR WAS REMOVED AND INSPECTED. THE ACTUATOR WAS FOUND IN THE FLAPS UP POSITION. THE LEFT FLAP WAS FOUND VIRTUALLY UNDAMAGED AND IT'S CONTROL SYSTEM INTACT. THE RIGHT ELEVATOR WAS FOUND VIRTUALLY UNDAMAGED HOWEVER ITS PUSHROD TUBE WAS FOUND SHEARED JUST ABOVE THE THREADED ROD END. AN INSPECTION OF MAIN WING SPAR REVEALED NO DISCREPANCIES. INSPECTION OF THE FORWARD WING TANK SUPPORT BRACKET WAS NOT POSSIBLE DUE TO IMPACT DAMAGE. AN INSPECTION OF THE LEFT REAR SPAR ATTACH POINT WAS FOUND INTACT WITH EVIDENCE THAT THE WING HAD SHIFTED DOWN, PRESUMED TO HAPPENED DURING THE IMPACT. AN INSPECTION OF THE RIGHT REAR SPAR ATTACH POINT FOUND THE WING REAR SPAR BRACKET HAD FRACTURED AWAY FROM THE FUSELAGE ATTACH BRACKET. UPON REMOVAL OF THE AIRCRAFT TO A FLAT BED TRUCK, THE RIGHT REAR SPAR ATTACH HARDWARE WAS REMOVED FROM THE FUSELAGE ATTACH BRACKET FOR INSPECTION. PORTIONS OF THE WING REAR SPAR BRACKET REMAINED IN THE FUSELAGE ATTACH BRACKET. INSPECTION OF THESE PIECES FOUND THE BRACKET HAD FAILED ON BOTH THE VERTICAL AND HORIZONTAL AXIS. EACH FAILURE POINT ORIGINATED FROM THE ATTACH BOLT HOLE. EXAMINATION OF THE VERTICAL FAILURE FOUND 45 DEGREE SHEAR LIPS. INSPECTION OF THE HORIZONTAL FAILURE FOUND NOT SHEAR LIPS RAISING QUESTIONS ABOUT THE INTEGRITY OF THIS REAR SPAR. INSPECTION OF THE FUSELAGE RIGHT REAR SPAR ATTACH BRACKETS FOUND VERY LITTLE DAMAGE THAT WOULD HAVE BEEN CONSISTENT WITH IMPACT DAMAGE NECESSARY TO CAUSE THE FAILURE OF THE WING REAR SPAR. DURING A FOLLOW UP INSPECTION OF THE AIRCRAFT AT AIR TRANSPORT IN PHOENIX AZ, THE WING AND FUSELAGE ATTACHMENT STRUCTURES WERE REMOVED FOR ANALYSIS BY THE NTSB. DURING RECONSTRUCTION OF THE WING SPAR, IT WAS APPARENT THAT THE WING SPAR MOUNTING HOLE WAS SEVERELY ELONGATED ON THE HORIZONTAL AXIS. BOTH THE REAR WING SPAR AND FUSELAGE ATTACH BRACKETS WERE SENT TO THE NTSB LAB FOR ANALYSIS. AN INTERVIEW WITH ^PRIVACY DATA OMITTED^, THE BUILDER'S HELPER, WAS CONDUCTED ON DECEMBER 29. ^PRIVACY DATA OMITTED^ DID NOT RECALL ANY ISSUES WITH DRILLING THE REAR SPAR ATTACHMENT HOLE DURING THE CONSTRUCTION OF THE AIRCRAFT. AT THIS TIME, THE CAUSE OF THE REAR SPAR FAILURE COULD NOT BE DETERMINED AND FURTHER DATA FROM METALLURGIC ANALYSIS OF THE SPAR IS PENDING.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.