 What if an aircraft could fly without the rear vertical stabilizer and rudder? What would be the advantages? Better yet, how could it be done? The X-31 international test team is helping explore these possibilities at NASA's Dryton Flight Research Center, Edwards, California. X-31 team members previously demonstrated supersonic quasi-tailess capabilities in March of 1994. Quasi-tailess is a state of simulated reduced tail, or tailess flight, through destabilizing feedback to the ship's rudder and ailerons. Close loop stability and control is then completely provided by the X-31's unique thrust vectoring system. This work has captured the interest of the Joint Advanced Strike Technology, or JAST, program group. Members from the U.S. Navy, Marine Corps, and Air Force have joined to gather technology for the next generation of fighter aircraft. The benefits are decreased weight and drag. This will increase range and make future aircraft smaller, resulting in less expensive, more affordable strike fighter aircraft. The X-31 team at NASA Dryton was chosen because the X-31 is capable of gathering this data now, not three to five years in the future. The X-31 test team and JAST will conduct a two-phase flight experiment to include simulated power approach and ground attack maneuvers at low altitude for multiple levels of destabilization. Phase 1 emphasis will be on validating the simulation model for tailless flight. Test maneuvers will be conducted at 20,000 feet and 8,000 feet and lower in both cruise and power approach configurations at Mach numbers 0.34, 0.6, and 0.8. The levels of de-augmented stability from the rudder and ailerons plan to be varied a minimum of between 100% tail off to full tail during this test phase of roughly 10 to 12 sorties. The power approach tailless flight was initiated by the ITO test team September 1. Phase 2 testing will demonstrate the operational viability of tailless flight through quasi-tailless testing. Simulated ground attack maneuvers and precision approaches will be flown. The objective will be to provide flight validated data supporting future tailless designs. 8 to 10 test flights under these conditions should meet those objectives. Upon completion, the X-31 test team will analyze the test data and provide a final report and briefing of their accomplishments in quasi-tailless research to the JAST program managers in Washington, D.C. The ITO test team at NASA Dryden continues to plan for a reduced-tail tailless X-31 flight program during calendar year 1995. The X-31 international test team demonstrated supersonic quasi-tailless capabilities in March 1994. Quasi-tailless is a state of simulated reduced-tail or tailless flight through destabilizing feedback to the ship's rudder and ailerons. At this point, the X-31's thrust vectoring system provides closed-loopsed ability and control. Tailless flight would decrease aircraft weight and drag, increasing their range. This would lead to smaller aircraft in the future, resulting in less expensive, more affordable strike fighter aircraft. The X-31 project at NASA Dryden was chosen because the aircraft can provide immediate test results. The X-31 test team and the Joint Advanced Strike Technology team from the U.S. Air Force, Navy and Marine Corps will conduct a two-phased flight experiment to gather this data. Phase 1 emphasis will be on validating the simulation model for tailless flight. Test maneuvers will be conducted at 20,000 and 8,000 feet and lower in both cruise and power approach configurations. This test phase began September 1, 1994. Phase 2 testing will demonstrate the operational viability of tailless flight through quasi-tailless testing. Simulated ground attack maneuvers and precision approaches will be flown. Upon completion, the X-31 test team will analyze the data and provide a final report to the jazzed program managers in Washington, D.C. From NASA's Dryden Flight Research Center, Edwards, California, I'm Roger Williams.