The commander was conducting a revalidation of the handling pilot’s SEP class rating. As part of this training flight, a flapless circuit to Runway 24 was flown and the handling pilot raised the landing gear on the crosswind leg, just prior to turning downwind. The commander reported that raising the landing gear was not standard procedure in the aircraft when flying circuits, and that she intended to tell the handing pilot to lower it once the gear had finished travelling.
A protracted period of radio communication from two aircraft ahead of G-TOTO in the circuit distracted the handling pilot from lowering the landing gear, and the commander from noticing that it had not been lowered. Further distraction was caused by an aircraft joining the circuit overhead, and consequently the landing gear was not lowered as part of the downwind checks. The commander reported that the low sun angle and attention to trees on the flapless approach demanded greater attention than normal, and the landing was completed without selecting the landing gear DOWN.
After the aircraft was recovered, a maintenance inspection revealed that the landing gear warning horn was not working.