What happened
A wheels-up landing occurred on runway 29 at Effingham County Memorial Airport in Effingham, Illinois. During the approach, the pilot reported completing a seven-item checklist, which included verifying the landing gear position. As the aircraft transitioned to the base leg, the pilot began extending the flaps.
The aircraft touched down on the runway centerline, at which point the pilot noted a low vibration. When the throttles were moved to the idle position, the gear warning horn activated; the pilot initially mistook this sound for the stall warning horn. During the subsequent recovery of the aircraft, the pilot set the master switch to the 'ON' position, which again triggered the landing gear warning horn. Upon moving the landing gear handle to the down position, the gear extended. The pilot noted that the flap control and the landing gear control were positioned approximately five inches apart.