What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On 04/02/2011, a rebuilt engine was installed in the left hand position. On 04/03/2011, a test flight was performed that involved three takeoffs and landings. A test flight was again performed on 04/06/2011; however, during landing the pilot was unable to confirm a landing gear safe condition. After manual gear extention, a fly by was performed and the gear was reported down but a locked condition could not be confirmed. During landing, the aircraft rolled out; however, when the pilot initiated a 180 degree turn to back taxi, the right main gear collapsed.
As the FAA filed it
ON 04/02/2011, A REBUILT ENGINE WAS INSTALLED IN THE LEFT HAND POSITION. ON 04/03/2011, A TEST FLIGHT WAS PERFORMED THAT INVOLVED THREE TAKEOFFS AND LANDINGS. A TEST FLIGHT WAS AGAIN PERFORMED ON 04/06/2011; HOWEVER, DURING LANDING THE PILOT WAS UNABLE TO CONFIRM A LANDING GEAR SAFE CONDITION. AFTER MANUAL GEAR EXTENTION, A FLY BY WAS PERFORMED AND THE GEAR WAS REPORTED DOWN BUT A LOCKED CONDITION COULD NOT BE CONFIRMED. DURING LANDING, THE AIRCRAFT ROLLED OUT; HOWEVER, WHEN THE PILOT INITIATED A 180 DEGREE TURN TO BACK TAXI, THE RIGHT MAIN GEAR COLLAPSED.