Negative transfer is defined in the context of this paper as the transfer from one cockpit to another--of different design or configuration--of habits or responses which were appropriate in the former but are inappropriate in the latter, thereby posing a threat to flying safety. This danger has been demonstrated not only experimentally but also in a number of aircraft accident investigation reports. As new aircraft become available to the commercial, military, and private sectors and pilots consequently must transition from older to newer models, the phenomenon of negative transfer becomes increasingly significant. To illustrate the concept of negative transfer and aviation, the author compares the cockpits of two USAF aircraft and how their differences could adversely affect pilot performance. Recommendations are then made on ways organizational flight surgeons can minimize the negative transfer threat to aviation.