Human Systems Integration Division @ NASA Ames

This study used a human-in-the-loop simulation to examine the feasibility of mixed equipage operations in an automated separation assurance environ- ment under higher traffic densities. The study involved two aircraft equi- page alternatives�with and without data link�and four traffic conditions. In all traffic conditions, the unequipped traffic count was increased linearly throughout the scenario from approximately 5�20 aircraft. The first condi- tion consisted solely of this unequipped traffic, while the remaining three conditions included a constant number of equipped aircraft operating with- in the same airspace: 15 equipped aircraft in the second condition, 30 in the third condition, and 45 in the fourth condition. If traffic load became exces- sive during any run, participants were instructed to refuse sector entry to inbound unequipped aircraft until sector load became manageable. Results showed a progressively higher number of unequipped aircraft turned away under the second, third, and fourth scenario conditions. Controller self- reported workload also increased progressively with the increasing level of equipped aircraft. Participants rated the mixed operations concept as ac- ceptable, with some qualifications about procedures and information dis- plays. These results showed that mixed operations might be feasible in the same airspace if unequipped aircraft count is held to a workable level. This level will decrease with increasing complexity. The results imply that an integrated airspace configuration is feasible to a limit. The results also indicate that the conflict detection and resolution automation, equipage, and traffic density are important factors that must be considered in air- space configuration.