What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The accident aircraft had just departed the private airfield at the Collings Foundation and was making closed pattern operations for a demonstration in front of a crowd. There was an event highlighting world war 1 (WW1) aviation occurring at the airstrip. According to the pilot, a preflight engine run was completed, and the fuel air mixture was adjusted to deliver full power. The pilot stated that he departed and made one approach to landing, which he realized that he was landing long, and attempted a go-around. On the upwind leg, he began to lose power. After a few seconds, power was restored and he began to maneuver toward the downwind leg, which was over a small river and provided some emergency landing options. On the downwind leg, at approximately 500’ AGL, the engine again lost power momentarily. The pilot was able to maneuver for a base leg to the grass runway. Power was restored, but as evidenced by eyewitness video, the engine was not running normally. As the pilot made a last second attempt to line up with the runway and level the wings, he was not able to arrest the high rate of descent. On impact with the grass runway, the main landing gear collapsed and the aircraft nosed-over and came to rest upside down. The pilot was able to extricate himself immediately, with no injuries and there was no post-crash fire.
Post accident investigation showed that the propeller was shattered due to impact and had been rotating. Due to the type of engine (WW1 era rotary) it is not possible to determine if the rotation was evidence of producing power as the engine and propeller keep rotating even if adequate combustion is not occurring. Flight control continuity was observed, and no visible defects were found with the airframe, engine or propeller. Remaining fuel in the aircraft was observed to be of adequate quantity, and no contaminants were indicated. Impact damage was observed in the forward cockpit, landing gear, engine mount and wings. The pilot was interviewed, along with several eyewitnesses and industry experts in ww 1 era engines. Video evidence appears to show that the aircraft lost power, possibly due to a transient over-rich condition. As this engine has very rudimentary fuel and lubrication systems, a minor change in altitude and atmospheric conditions after engine run-up can create significant power fluctuations. Lack of evidence of any mechanical malfunction, and analysis of video evidence indicates that the engine became overly-rich while climbing. The lack of a mixture control or throttle combine to create a situation where the only action available to the pilot is to allow the engine to windmill for a period of time to clear the excess fuel. In the case, the aircraft did not have sufficient altitude to adequately restore power. The pilot was able to maneuver the aircraft with a high level of skill to bring the aircraft onto the safest possible landing site while avoiding an accelerated stall.
As the FAA filed it
THE ACCIDENT AIRCRAFT HAD JUST DEPARTED THE PRIVATE AIRFIELD AT THE COLLINGS FOUNDATION AND WAS MAKING CLOSED PATTERN OPERATIONS FOR A DEMONSTRATION IN FRONT OF A CROWD. THERE WAS AN EVENT HIGHLIGHTING WORLD WAR 1 (WW1) AVIATION OCCURRING AT THE AIRSTRIP. ACCORDING TO THE PILOT, A PREFLIGHT ENGINE RUN WAS COMPLETED, AND THE FUEL AIR MIXTURE WAS ADJUSTED TO DELIVER FULL POWER. THE PILOT STATED THAT HE DEPARTED AND MADE ONE APPROACH TO LANDING, WHICH HE REALIZED THAT HE WAS LANDING LONG, AND ATTEMPTED A GO-AROUND. ON THE UPWIND LEG, HE BEGAN TO LOSE POWER. AFTER A FEW SECONDS, POWER WAS RESTORED AND HE BEGAN TO MANEUVER TOWARD THE DOWNWIND LEG, WHICH WAS OVER A SMALL RIVER AND PROVIDED SOME EMERGENCY LANDING OPTIONS. ON THE DOWNWIND LEG, AT APPROXIMATELY 500’ AGL, THE ENGINE AGAIN LOST POWER MOMENTARILY. THE PILOT WAS ABLE TO MANEUVER FOR A BASE LEG TO THE GRASS RUNWAY. POWER WAS RESTORED, BUT AS EVIDENCED BY EYEWITNESS VIDEO, THE ENGINE WAS NOT RUNNING NORMALLY. AS THE PILOT MADE A LAST SECOND ATTEMPT TO LINE UP WITH THE RUNWAY AND LEVEL THE WINGS, HE WAS NOT ABLE TO ARREST THE HIGH RATE OF DESCENT. ON IMPACT WITH THE GRASS RUNWAY, THE MAIN LANDING GEAR COLLAPSED AND THE AIRCRAFT NOSED-OVER AND CAME TO REST UPSIDE DOWN. THE PILOT WAS ABLE TO EXTRICATE HIMSELF IMMEDIATELY, WITH NO INJURIES AND THERE WAS NO POST-CRASH FIRE.
POST ACCIDENT INVESTIGATION SHOWED THAT THE PROPELLER WAS SHATTERED DUE TO IMPACT AND HAD BEEN ROTATING. DUE TO THE TYPE OF ENGINE (WW1 ERA ROTARY) IT IS NOT POSSIBLE TO DETERMINE IF THE ROTATION WAS EVIDENCE OF PRODUCING POWER AS THE ENGINE AND PROPELLER KEEP ROTATING EVEN IF ADEQUATE COMBUSTION IS NOT OCCURRING. FLIGHT CONTROL CONTINUITY WAS OBSERVED, AND NO VISIBLE DEFECTS WERE FOUND WITH THE AIRFRAME, ENGINE OR PROPELLER. REMAINING FUEL IN THE AIRCRAFT WAS OBSERVED TO BE OF ADEQUATE QUANTITY, AND NO CONTAMINANTS WERE INDICATED. IMPACT DAMAGE WAS OBSERVED IN THE FORWARD COCKPIT, LANDING GEAR, ENGINE MOUNT AND WINGS. THE PILOT WAS INTERVIEWED, ALONG WITH SEVERAL EYEWITNESSES AND INDUSTRY EXPERTS IN WW 1 ERA ENGINES. VIDEO EVIDENCE APPEARS TO SHOW THAT THE AIRCRAFT LOST POWER, POSSIBLY DUE TO A TRANSIENT OVER-RICH CONDITION. AS THIS ENGINE HAS VERY RUDIMENTARY FUEL AND LUBRICATION SYSTEMS, A MINOR CHANGE IN ALTITUDE AND ATMOSPHERIC CONDITIONS AFTER ENGINE RUN-UP CAN CREATE SIGNIFICANT POWER FLUCTUATIONS. LACK OF EVIDENCE OF ANY MECHANICAL MALFUNCTION, AND ANALYSIS OF VIDEO EVIDENCE INDICATES THAT THE ENGINE BECAME OVERLY-RICH WHILE CLIMBING. THE LACK OF A MIXTURE CONTROL OR THROTTLE COMBINE TO CREATE A SITUATION WHERE THE ONLY ACTION AVAILABLE TO THE PILOT IS TO ALLOW THE ENGINE TO WINDMILL FOR A PERIOD OF TIME TO CLEAR THE EXCESS FUEL. IN THE CASE, THE AIRCRAFT DID NOT HAVE SUFFICIENT ALTITUDE TO ADEQUATELY RESTORE POWER. THE PILOT WAS ABLE TO MANEUVER THE AIRCRAFT WITH A HIGH LEVEL OF SKILL TO BRING THE AIRCRAFT ONTO THE SAFEST POSSIBLE LANDING SITE WHILE AVOIDING AN ACCELERATED STALL.