What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The pilot was performing a series of "fast taxi" on the runway while troubleshooting carburetor issues during phase one certification for experimental aircraft. The pilot unintentionally allowed the aircraft to lift off the runway. He decided to continue flying the aircraft around the traffic pattern due to not having adequate length to stop the aircraft back on the runway. At 400 feet AGL, the engine lost power. The pilot tried different power settings to regain power but was unsuccessful. He turned the aircraft to return to the airport. He landed in a field short of the runway. The aircraft hit train tracks, flipped over, and received minor damage.
As the FAA filed it
THE PILOT WAS PERFORMING A SERIES OF "FAST TAXI" ON THE RUNWAY WHILE TROUBLESHOOTING CARBURETOR ISSUES DURING PHASE ONE CERTIFICATION FOR EXPERIMENTAL AIRCRAFT. THE PILOT UNINTENTIONALLY ALLOWED THE AIRCRAFT TO LIFT OFF THE RUNWAY. HE DECIDED TO CONTINUE FLYING THE AIRCRAFT AROUND THE TRAFFIC PATTERN DUE TO NOT HAVING ADEQUATE LENGTH TO STOP THE AIRCRAFT BACK ON THE RUNWAY. AT 400 FEET AGL, THE ENGINE LOST POWER. THE PILOT TRIED DIFFERENT POWER SETTINGS TO REGAIN POWER BUT WAS UNSUCCESSFUL. HE TURNED THE AIRCRAFT TO RETURN TO THE AIRPORT. HE LANDED IN A FIELD SHORT OF THE RUNWAY. THE AIRCRAFT HIT TRAIN TRACKS, FLIPPED OVER, AND RECEIVED MINOR DAMAGE.