What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) On June 20, 2004, about 1748 pacific daylight time, a test TST-10M glider, N410JP, impacted the terrain and was destroyed while maneuvering for landing at the bergseth field airport near Enumclaw, Washington. The self-launching single-seat sailplane was registered to the pilot and was being operated as a visual flight rules (VFR) flight under the provisions of 14 CFR, part 91 when the accident occurred. The pilot was fatally injured in the accident. The witness reported that the pilot's downwind leg appeared normal, however, the base leg to final turn was close to the runway end, resulting in a higher than normal glidepath to final. Shortly after crossing the landing threshold the glider pitched up, in conjunction with the speed brakes retracting, and the pilot initiating a turn to the right (south). The pilot rolled to wings level attitude momentarily before entering a left turn. As the aircraft turned to the left it pitched to a nose-low attitude and impacted the terrain.
As the FAA filed it
(-23) ON JUNE 20, 2004, ABOUT 1748 PACIFIC DAYLIGHT TIME, A TEST TST-10M GLIDER, N410JP, IMPACTED THE TERRAIN AND WAS DESTROYED WHILE MANEUVERING FOR LANDING AT THE BERGSETH FIELD AIRPORT NEAR ENUMCLAW, WASHINGTON. THE SELF-LAUNCHING SINGLE-SEAT SAILPLANE WAS REGISTERED TO THE PILOT AND WAS BEING OPERATED AS A VISUAL FLIGHT RULES (VFR) FLIGHT UNDER THE PROVISIONS OF 14 CFR, PART 91 WHEN THE ACCIDENT OCCURRED. THE PILOT WAS FATALLY INJURED IN THE ACCIDENT. THE WITNESS REPORTED THAT THE PILOT'S DOWNWIND LEG APPEARED NORMAL, HOWEVER, THE BASE LEG TO FINAL TURN WAS CLOSE TO THE RUNWAY END, RESULTING IN A HIGHER THAN NORMAL GLIDEPATH TO FINAL. SHORTLY AFTER CROSSING THE LANDING THRESHOLD THE GLIDER PITCHED UP, IN CONJUNCTION WITH THE SPEED BRAKES RETRACTING, AND THE PILOT INITIATING A TURN TO THE RIGHT (SOUTH). THE PILOT ROLLED TO WINGS LEVEL ATTITUDE MOMENTARILY BEFORE ENTERING A LEFT TURN. AS THE AIRCRAFT TURNED TO THE LEFT IT PITCHED TO A NOSE-LOW ATTITUDE AND IMPACTED THE TERRAIN.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.