Comparative Evaluation of Butterfly and 4-Post Tails on a 5th-Generation Fighter Configuration

摘要

The Fifth Generation Target Study (5GTS) was a conceptual design task for a large target drone aircraft capable of representing key 5th generation fighter signature and performance attributes. The target drone's intended uses are to test air-to-air and surface-to-air missiles, and to ensure that modern tracking systems are capable of identifying and targeting 5th generation fighters. Previous wind tunnel testing of a candidate 5GTS configuration with a 4-post empennage revealed poor lateral-directional stability characteristics at moderate angles of attack. Testing described in this report examined the effects of replacing the 4-post tails with butterfly tails on six different candidate 5GTS configurations. Results showed that butterfly tails consistently displayed superior lateral-directional stability characteristics when compared with equivalent 4-post tails. However, all butterfly-tail configurations exhibited pitchup, that is loss of pitch stability at moderate angles of attack. This makes them unattractive for use on a target drone, which must have an inexpensive flight control system.