What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
While in the pattern at S33, instrutor and student started practice for engine failure below 3000' while on the crosswind leg. Ran through all checklists for engine failure while at low altitude and simulated feather on the left engine with power. Performed a gumps/before landing check on downwind leg. Student deployed flaps to 40° on base and instructor retracted them to 25° for single engine procedures. Instructor performed final check but did not verify the gear handle was in the down position. Neither student or instructor remember hearing the gear warning horn during final approach. Lined up on final to land and did a stabilized approach check. Aircraft landed on centerline with gear retracted. Landing gear warning horn could be heard after engines were shutdown.
As the FAA filed it
WHILE IN THE PATTERN AT S33, INSTRUTOR AND STUDENT STARTED PRACTICE FOR ENGINE FAILURE BELOW 3000' WHILE ON THE CROSSWIND LEG. RAN THROUGH ALL CHECKLISTS FOR ENGINE FAILURE WHILE AT LOW ALTITUDE AND SIMULATED FEATHER ON THE LEFT ENGINE WITH POWER. PERFORMED A GUMPS/BEFORE LANDING CHECK ON DOWNWIND LEG. STUDENT DEPLOYED FLAPS TO 40° ON BASE AND INSTRUCTOR RETRACTED THEM TO 25° FOR SINGLE ENGINE PROCEDURES. INSTRUCTOR PERFORMED FINAL CHECK BUT DID NOT VERIFY THE GEAR HANDLE WAS IN THE DOWN POSITION. NEITHER STUDENT OR INSTRUCTOR REMEMBER HEARING THE GEAR WARNING HORN DURING FINAL APPROACH. LINED UP ON FINAL TO LAND AND DID A STABILIZED APPROACH CHECK. AIRCRAFT LANDED ON CENTERLINE WITH GEAR RETRACTED. LANDING GEAR WARNING HORN COULD BE HEARD AFTER ENGINES WERE SHUTDOWN.