What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Aiarcraft wing failed under unknown phase. Shows exceeded desig load. (.4) the aircraft, equipped with dual controls, departed for a demonstration flight with the pilot in the front seat and the pilot-rated passenger in the back. A demonstration flight includes only low-g maneuvers. The aircraft, designed for aerobatics, had, since its manufacture, performed aerobatic maneuvers on previous flights. The maximum allowable gross weight for aerobatics is 1,550 pounds. The aircraft weighed an estimated at 1,639 pounds at the time of the accident. An ag pilot reported seeing the aircraft in a shallow climb about 500 feet AGL. An eyewitness, over a mile from the accident site, heard an engine surging and looked up. He saw a yellow aircraft flying straight and level, about 1,000 feet AGL. As he watched, something fell from the aircraft, which was followed by a loud boom. The aircraft pitched up, nosed over, rolled, entering a spin that continued until impact. The outboard portion of the left wing was found 0.17 miles from the crash site. The main spar had evidence of a ductile fracture due to a positive overload. The spar material met design specifications for metal composition and hardness. There was no evidence of fatigue or corrosion. The outboard section of the left wing did not exhibit any evidence of aeroelastic divergence. A flutter test showed the aircraft design was free from flutter to speeds above its design envelope. Wing load testing showed the wing design was able to support a limit load, +6 g's. the wing also supported an ultimate load, +9 g's, for 3 seconds without failure. The engine management system nonvolatile memory readout provided data points equivalent to 191 mph in level flight. Maneuvering speed under the same conditions is 142 mph. (-23) aircraft crashed under unknown circumstances approximately 11 miles south of Blythe, CA. At 0700 PDT. Aircraft was a vans RV8 and was destroyed, with the two occupants, both fatally injured. The pilot will not be reexamined due to the fatal injuries he received in the crash.
As the FAA filed it
AIARCRAFT WING FAILED UNDER UNKNOWN PHASE. SHOWS EXCEEDED DESIG LOAD. (.4) THE AIRCRAFT, EQUIPPED WITH DUAL CONTROLS, DEPARTED FOR A DEMONSTRATION FLIGHT WITH THE PILOT IN THE FRONT SEAT AND THE PILOT-RATED PASSENGER IN THE BACK. A DEMONSTRATION FLIGHT INCLUDES ONLY LOW-G MANEUVERS. THE AIRCRAFT, DESIGNED FOR AEROBATICS, HAD, SINCE ITS MANUFACTURE, PERFORMED AEROBATIC MANEUVERS ON PREVIOUS FLIGHTS. THE MAXIMUM ALLOWABLE GROSS WEIGHT FOR AEROBATICS IS 1,550 POUNDS. THE AIRCRAFT WEIGHED AN ESTIMATED AT 1,639 POUNDS AT THE TIME OF THE ACCIDENT. AN AG PILOT REPORTED SEEING THE AIRCRAFT IN A SHALLOW CLIMB ABOUT 500 FEET AGL. AN EYEWITNESS, OVER A MILE FROM THE ACCIDENT SITE, HEARD AN ENGINE SURGING AND LOOKED UP. HE SAW A YELLOW AIRCRAFT FLYING STRAIGHT AND LEVEL, ABOUT 1,000 FEET AGL. AS HE WATCHED, SOMETHING FELL FROM THE AIRCRAFT, WHICH WAS FOLLOWED BY A LOUD BOOM. THE AIRCRAFT PITCHED UP, NOSED OVER, ROLLED, ENTERING A SPIN THAT CONTINUED UNTIL IMPACT. THE OUTBOARD PORTION OF THE LEFT WING WAS FOUND 0.17 MILES FROM THE CRASH SITE. THE MAIN SPAR HAD EVIDENCE OF A DUCTILE FRACTURE DUE TO A POSITIVE OVERLOAD. THE SPAR MATERIAL MET DESIGN SPECIFICATIONS FOR METAL COMPOSITION AND HARDNESS. THERE WAS NO EVIDENCE OF FATIGUE OR CORROSION. THE OUTBOARD SECTION OF THE LEFT WING DID NOT EXHIBIT ANY EVIDENCE OF AEROELASTIC DIVERGENCE. A FLUTTER TEST SHOWED THE AIRCRAFT DESIGN WAS FREE FROM FLUTTER TO SPEEDS ABOVE ITS DESIGN ENVELOPE. WING LOAD TESTING SHOWED THE WING DESIGN WAS ABLE TO SUPPORT A LIMIT LOAD, +6 G'S. THE WING ALSO SUPPORTED AN ULTIMATE LOAD, +9 G'S, FOR 3 SECONDS WITHOUT FAILURE. THE ENGINE MANAGEMENT SYSTEM NONVOLATILE MEMORY READOUT PROVIDED DATA POINTS EQUIVALENT TO 191 MPH IN LEVEL FLIGHT. MANEUVERING SPEED UNDER THE SAME CONDITIONS IS 142 MPH. (-23) AIRCRAFT CRASHED UNDER UNKNOWN CIRCUMSTANCES APPROXIMATELY 11 MILES SOUTH OF BLYTHE, CA. AT 0700 PDT. AIRCRAFT WAS A VANS RV8 AND WAS DESTROYED, WITH THE TWO OCCUPANTS, BOTH FATALLY INJURED. THE PILOT WILL NOT BE REEXAMINED DUE TO THE FATAL INJURIES HE RECEIVED IN THE CRASH.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.