The use of subjective measures for sensor assignment in a two-seat fighter aircraft

This thesis explores the use of subjective measures for determining sensor assignment in a two-seat fighter aircraft, the F-15E. The F-15E is the USAF's newest multi-role fighter aircraft, and it has a formidable air-to-air capability which is centered around its radar. The air-to-air mode of an infrared targeting pod (TGP) provides a complement to radar operations. The aircrew of this aircraft consists of a pilot and a weapons system officer (WSO). Sensor assignment is of critical importance to the success of the mission and the survival of the aircrew. Historically, the pilot primarily performed basic aircraft control functions until weapons employment, while the WSO performed targeting functions with the radar. But with the availability of two sensors, the assignment of radar and TGP responsibility was uncertain.

Direct mission success performance measures would not be adequate for sensor assignment conclusions because of the excessive number of combat related variables. Since both the ability for the pilot to effectively operate a sensor during critical piloting periods, and the WSO to operate two sensors simultaneously was in question due to potentially high workloads, workload assessment was considered crucial. Physiological workload measurement systems were not considered viable, so a subjective measurement system, a modified Bedford scale, was chosen. For relating aircrew preference comparisons between three tasking assignments, the analytical hierarchy process was used. Limited postflight availability and aircrew experience using subjective measures were important considerations leading to the selection of these methods. A questionnaire comments section, one-on-one interviews, and test team discussions were also accomplished.

The overall test methodology was successful in developing working considerations for sensor assignment for various critical tactical conditions. Neither workload or comparison ratings alone would have been successful in reaching the conclusions drawn from combining both methodologies. Interviews and test team meetings were the major source of data used in reaching conclusions. Because of the large number of variables in this test environment, workload and comparison ratings had reduced effectiveness and increased data reduction requirements. While this limited their usefulness in determining conclusions to a secondary role, their inclusion in the test raised aircrew awareness, and forced aircrews to make sensor assignment preference decisions. Overall, their inclusion in the test was helpful but not critical to reaching assignment conclusions.