Summary: GAO discussed the Airborne Self-Protection Jammer (ASPJ) program, focusing on: (1) how the Department of Defense reported and used ASPJ test results in its low-rate initial production decision; and (2) the Department of Defense (DOD) Inspector General's (IG) conclusions from its ASPJ program audit. GAO noted that: (1) the purpose of the ASPJ test program is to determine whether the system is capable of effectively countering defensive threat systems by verifying and predicting operational effectiveness and suitability; (2) from 1986 through 1988, the Navy and the Air Force conducted separate developmental testing programs and presented the test results at briefings to cognizant boards and committees prior to the low-rate initial production review, but some of the briefings on test results might have been overly optimistic; (4) regardless of ASPJ test results, decisionmakers approved low-rate initial production knowing that ASPJ had not satisfactorily met exit criteria; (5) an Air Force test report indicated that it had assessed all critical operational issues and objectives in the test plan, but could not determine many ratings because the full-scale development version of ASPJ was not mature; (6) the IG audit confirmed that ASPJ program problems would probably be exacerbated by the Air Force's withdrawal from the program, particularly the increase in unit cost that resulted from the drop in planned buys; and (7) it agreed with the IG recommendation to stretch out deliveries and eliminate follow-on limited production decisions.