On March 6, 1998, at 1530 mountain standard time, a Mooney M20C, N5653Q, sustained substantial damage during landing at Jefferson County Airport, Broomfield, Colorado. The private pilot and his two passengers were not injured. No flight plan was filed for this local area personal flight operating under Title 14 CFR Part 91. Visual meteorological conditions prevailed. The flight originated at 1440. According to the pilot, he was conducting touch-and-go landings and was on approach for runway 29L when his daughter got air sick. The pilot was trying to find her an air sickness bag and forgot to lower the landing gear. In a telephone interview with the investigator-in-charge (IIC), the pilot said he did not hear the landing gear warning horn and did not think that he could with his head set on. He became aware the landing gear was not down when the hull began to scrape on the runway. According to his written statement, when the aircraft came to a stop, he and his passengers exited the aircraft after he shut off the fuel and pulled the circuit breakers.