The aircraft was on a regular freight run which the pilot had flown numerous times. An area of turbulence was encountered which led the pilot to reduce to turbulence penetration speed. When the throttles were closed, the landing gear warning horn sounded. After a short time, the pilot felt that the horn was affecting his concentration so he pulled the warning horn circuit breaker. As the pilot was conducting the pre-landing checks, but before he selected the landing gear down, the Control Tower requested him to reduce to minimum approach speed because of departing traffic ahead. The aircraft subsequently landed with the wheels in the fully retracted position. No fault was found with the landing gear system. The landing gear warning horn circuit breaker was in the OUT position when the aircraft was inspected. There is some evidence that the pilot was fatigued.
