In an effort to further evaluate the effects of Ecological Interface Design on acquiring expertise, this paper presents the results of an investigation into how Ecological Interface Design could possibly promote discovery learning processes in the Air Traffic Control domain through the application of an instructional design model, and how it could thereby support novices in picking up an implicit rule of thumb. A between participants experiment (N = 28) was performed through which participants, divided over two groups, were guided by means of a training script developed according to the Four-Component Instructional Design model. Participants from both groups had to perform a simplified Conflict Detection & Resolution task in which the rule of thumb was implicitly integrated. In addition, one group received additional support from an ecologically designed cognitive tool that was unexpectedly removed after a transfer manipulation. Results show that applying an instructional design method to the experiment design indeed leads to a more structured learning process and participants making significantly more use of optimal strategies, corresponding to the execution of the rule of thumb. Additionally, being trained with the cognitive tool leads to an increased awareness of the implicit rule of thumb but does not lead to an increased use of this rule. It was furthermore found that participants, who were trained with the tool, showed increased dependency on this tool. It is therefore recommended to further extend the experiment design and investigate whether including additional instructional design elements, such as phased visual elimination of the elements of the cognitive tool, could reduce participants’ dependency.