This paper reports the development of a practical tool that provides expert feedback to students following an extended simulation exercise in cross-country flight planning. In contrast to development for laboratory settings, the development of an expert instructional product for everyday use posed some interesting challenges, including dealing with a larger content scope, less ideal and controllable content structure, greater emphasis on the completeness and continuity of the student experience, and more stringent limits on time and money. Moreover, the transition from laboratory to real world caused the developers to think more critically of the principles of instruction embodied in the product and to place less emphasis on computer tool and technique questions. The product, which will be used in the context of routine ab initio pilot training, is described in terms of how these problems were solved and what lessons were learned that can be applied to the development of future instructional systems involving expertise. [This paper was first published in "Interactive Learning International," Vol. 6, no. 2, 1990, 63-72, by John Wiley & Sons Ltd.]