What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The instructor and student pilot arrived at the Petaluma muni airport to practice landings. The student pilot is working toward her private license. They completed two landings successfully and on the third they were on a right downwind for runway 29. The instructor called for gear undercarriage mixture propeller (gump) and the student reached for the landing gear lever, another pilot reported final on runway 29 and they diverted my attention to look for the traffic and assumed the gear was down. She flared the aircraft at approximately 20 feet above the runway for a normal landing. The student reported she got distracted looking for the traffic on her side and did not ensure the gear was down. The aircraft settled on the undercarriage and skidded to a stop approximately 685 feet on centerline.
As the FAA filed it
THE INSTRUCTOR AND STUDENT PILOT ARRIVED AT THE PETALUMA MUNI AIRPORT TO PRACTICE LANDINGS. THE STUDENT PILOT IS WORKING TOWARD HER PRIVATE LICENSE. THEY COMPLETED TWO LANDINGS SUCCESSFULLY AND ON THE THIRD THEY WERE ON A RIGHT DOWNWIND FOR RUNWAY 29. THE INSTRUCTOR CALLED FOR GEAR UNDERCARRIAGE MIXTURE PROPELLER (GUMP) AND THE STUDENT REACHED FOR THE LANDING GEAR LEVER, ANOTHER PILOT REPORTED FINAL ON RUNWAY 29 AND THEY DIVERTED MY ATTENTION TO LOOK FOR THE TRAFFIC AND ASSUMED THE GEAR WAS DOWN. SHE FLARED THE AIRCRAFT AT APPROXIMATELY 20 FEET ABOVE THE RUNWAY FOR A NORMAL LANDING. THE STUDENT REPORTED SHE GOT DISTRACTED LOOKING FOR THE TRAFFIC ON HER SIDE AND DID NOT ENSURE THE GEAR WAS DOWN. THE AIRCRAFT SETTLED ON THE UNDERCARRIAGE AND SKIDDED TO A STOP APPROXIMATELY 685 FEET ON CENTERLINE.