This article relates the construction and findings of an intervention at an airport following a safety incident that uncovered a deviation of communication practice between two air traffic controllers for handling small aircraft traffic on a secondary runway. The intervention was carried out by coaching and empowering a local team so that they would work with the air traffic controllers to understand the reasons for the deviation, involving the training of controllers to observe normal work practices in the control tower and its effects on local safety management practices. The results in terms of adapting scientific observation methods to a local issue and subsequent behavioural changes in attitudes towards the deviation of formal procedure are discussed.