The design of the aircraft engine-maintainer interface directly impacts propulsion system performance. The safety and reliability of the aircraft engine is heavily dependent on the human performance of maintenance tasks. Maintainers are challenged to maintain engines of the aging fleet along with advanced engines which utilize emerging technologies. Domestic demographic indicators suggest that significant changes in the aircraft maintenance work force will occur in this decade. Interdependent global economic conditions have led to increased foreign sales and logistics support. Understanding the capabilities and limitations of these worldwide maintainers during preliminary engine design permits Human Factors Engineering (HFE) to specify HFE design criteria for incorporation into the system design. General Electric Aircraft Engines (GEAE) employs several techniques to conduct HFE analysis. The broad spectrum of HFE methodologies applied range from computational intensive Computer Aided Deign (CAD) systems with advanced HFE software, to controlled dynamic simulations conducted with mock-ups, tooling, and subjects in ergonomic laboratories. Incorporating HFE and maintainability by design is necessary to offset rising maintenance costs, and to ensure maintainer compatibility with the advanced propulsion and aircraft systems of today and tomorrow.