The flight instructor and the student were conducting a simulated single engine approach to landing when the accident occurred. During the landing approach, the flight instructor was monitoring other aircraft traffic in the area, and the student asked the instructor a question, which distracted the instructor from performing his normal prelanding checks and verifying that the airplane’s retractable landing gear was extended. As the approach continued, neither the student nor flight instructor noticed that the landing gear was not extended. The airplane landed with the landing gear in the retracted position. The airplane received substantial damage to the structural external longerons on the bottom of the fuselage. As a result of the accident, the flight school implemented additional training for instructors and students regarding checklist usage and additional crew procedures have been implemented to verify landing gear extension prior to landing. Additionally, the review of the accident will be included in future safety meetings.