What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) The last ATC contact with the airplane was by spirit of saint Louis tower, which cleared the pilot to transition their class d airspace enroute to 1H0. The airplane landed gear up at 1H0 at approximately 2145Z. The pilot stated he did not have any mechanical problems with the airplane and that the cause of the gear up landing was purely pilot error. The pilot stated he did not lean over the yoke to check the gear indicator lights and that was his big mistake. The gear selector switch was between the up and the down position. The gear selector switch is designed with only two positions, up and down. To move from either position it is necessary to pull the handle and then move it to the opposite position. The switch was found in a middle position. Apparently the pilot moved the gear handle, but did not move it fully into the down position. By failing to check the lights, the stage was set for the incident. Then, by the pilot's own admission, he failed to recognize the other clues that should have alereted him to something being amiss (aircraft floated a long way and seemed too close to the ground). Whether the gear warning horn activated or not could not be determined with certainty.
As the FAA filed it
(-23) THE LAST ATC CONTACT WITH THE AIRPLANE WAS BY SPIRIT OF SAINT LOUIS TOWER, WHICH CLEARED THE PILOT TO TRANSITION THEIR CLASS D AIRSPACE ENROUTE TO 1H0. THE AIRPLANE LANDED GEAR UP AT 1H0 AT APPROXIMATELY 2145Z. THE PILOT STATED HE DID NOT HAVE ANY MECHANICAL PROBLEMS WITH THE AIRPLANE AND THAT THE CAUSE OF THE GEAR UP LANDING WAS PURELY PILOT ERROR. THE PILOT STATED HE DID NOT LEAN OVER THE YOKE TO CHECK THE GEAR INDICATOR LIGHTS AND THAT WAS HIS BIG MISTAKE. THE GEAR SELECTOR SWITCH WAS BETWEEN THE UP AND THE DOWN POSITION. THE GEAR SELECTOR SWITCH IS DESIGNED WITH ONLY TWO POSITIONS, UP AND DOWN. TO MOVE FROM EITHER POSITION IT IS NECESSARY TO PULL THE HANDLE AND THEN MOVE IT TO THE OPPOSITE POSITION. THE SWITCH WAS FOUND IN A MIDDLE POSITION. APPARENTLY THE PILOT MOVED THE GEAR HANDLE, BUT DID NOT MOVE IT FULLY INTO THE DOWN POSITION. BY FAILING TO CHECK THE LIGHTS, THE STAGE WAS SET FOR THE INCIDENT. THEN, BY THE PILOT'S OWN ADMISSION, HE FAILED TO RECOGNIZE THE OTHER CLUES THAT SHOULD HAVE ALERETED HIM TO SOMETHING BEING AMISS (AIRCRAFT FLOATED A LONG WAY AND SEEMED TOO CLOSE TO THE GROUND). WHETHER THE GEAR WARNING HORN ACTIVATED OR NOT COULD NOT BE DETERMINED WITH CERTAINTY.