What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Returning to Trenton Mercer Airport (kttn) the certificated flight instructor took controls to demonstrate a crosswind landing. Approximately 4 miles from the airport the CFI began the before landing checklist and skipped the landing gear item due to distance from the airport.
While in the pattern the gear horn sounded and was silenced. The before landing checklist was never completed. Both the CFI and the commercial pilot receiving training did not realize the gear was up.
The aircraft touched-down with the gear up and slid off the runway into the grass where it came to rest. The aircraft sustained belly scrapes and a small wrinkle in one flap. In addition, the propellers were curled.
As the FAA filed it
RETURNING TO TRENTON MERCER AIRPORT (KTTN) THE CERTIFICATED FLIGHT INSTRUCTOR TOOK CONTROLS TO DEMONSTRATE A CROSSWIND LANDING. APPROXIMATELY 4 MILES FROM THE AIRPORT THE CFI BEGAN THE BEFORE LANDING CHECKLIST AND SKIPPED THE LANDING GEAR ITEM DUE TO DISTANCE FROM THE AIRPORT.
WHILE IN THE PATTERN THE GEAR HORN SOUNDED AND WAS SILENCED. THE BEFORE LANDING CHECKLIST WAS NEVER COMPLETED. BOTH THE CFI AND THE COMMERCIAL PILOT RECEIVING TRAINING DID NOT REALIZE THE GEAR WAS UP.
THE AIRCRAFT TOUCHED-DOWN WITH THE GEAR UP AND SLID OFF THE RUNWAY INTO THE GRASS WHERE IT CAME TO REST. THE AIRCRAFT SUSTAINED BELLY SCRAPES AND A SMALL WRINKLE IN ONE FLAP. IN ADDITION, THE PROPELLERS WERE CURLED.