Mixed Fleet Flying between Two Commercial Aircraft Types: an Empirical Evaluation of the Role of Negative Transfer

We examined the potential vulnerabilities of pilots flying a mixed fleet of two different aircraft types. A “worst case” scenario was evaluated in which a pilot, flying one type exclusively, would need to fly the different type, after 6 months without any recurrency training on the latter. These circumstances invite negative transfer of habits in the “old” aircraft, to performance in the “new” aircraft”. Documents of both aircraft were evaluated to establish those aspects of design and procedures differences that invite such negative transfer; a list of 36 such “vulnerabilities” were identified. Then 40 active commercial airline pilots from a US carrier participated in an evaluation of such negative transfer between two different types within the fleet. The sample was divided into 2 groups each of which normally flew one of the types and not the other. After training on the “new” type, each pilot returned to either 3 or 6 months of flying exclusively with their “old” type, and then returned for simulator evaluations on the “new” type that were targeted to reveal the 36 vulnerabilities. Even with power-sensitive statistical analyses, only slight evidence for negative transfer was found. Those areas where such transfer did emerge were targeted for recommendations of either procedural harmonization or minor design changes.