This paper examines the role of the exchange engineer in international technology transfer. It takes as example the transfer of aircraft carrier technology from Great Britain to the United States during World War I, and describes how that individual interpreted the design knowledge from the drawings, allowing the U.S. engineers to grasp the underlying principles of the new technology and adapt it to their own needs. The exchange engineer, a British constructor named Stanley V. Goodall, was brought to the United States to help lead the nascent effort in battlecruiser design. Within months of his arrival, he was assisting in the design of the then-novel aircraft carrier. The United States had plans and drawings of similar British ships, but this on its own would not allow a new design based on U.S. military needs. Using Goodall's designs and interpretation of the strategic and tactical requirements that led to the technical characteristics of the British carriers, the U.S. designers developed their own version of this new ship. The 1922 Washington Treaty stopped the construction of the battlecruisers (which were based on Goodall's designs), and instead the U.S. Navy built on their half-finished hulls, a pair of aircraft carriers Lexington and Saratoga, that also came from Goodall's designs. The first U.S. fleet aircraft carriers were therefore designed by a British constructor, demonstrating the utility of the exchange engineer as a vector in technology transfer. The conclusions argue that such exchanges bear the greatest fruit when the technologies address novel concepts of operation, rather than simply improving upon well-understood doctrine.