Traditionally, DOD’s combat aircraft have used on-board electronic warfare devices called jammers for self-protection against radar-controlled weapons, including missiles and anti-aircraft artillery. These jammers emit electronic signals from the aircraft to try to impede or deny the threat radar’s ability to locate the aircraft. DOD’s existing self-protection jamming systems for its tactical aircraft have limitations against certain threats, and these threats are expected to be improved. DOD has modified existing systems, such as the Air Force’s ALQ-131 used on the F-16 and the ALQ-135 on the F-15, and has developed a newer system, the Navy’s Airborne Self-Protection Jammer (ASPJ), which is being used on some F-14D and F/A-18C/D aircraft. As we have previously reported, however, testing after deployment has shown that the modified jammer systems have had problems, while operational testing of ASPJ and other jammers showed they were unable to meet effectiveness criteria against certain classified threats. In an attempt to overcome the limitations of the on-board jammers, the services are acquiring two new towed decoy systems, the ALE-50 and the RFCM, to enhance survivability against the radar-controlled threats. The ALE-50 towed decoy system is in production, while the future RFCM system is in development. The ALE-50’s towed decoy component generates and emits its own signals that are intended to lure an incoming radar-guided weapon away from the aircraft by presenting a more attractive target. To provide further improvement for selected Air Force and Navy aircraft, the RFCM is to provide more sophisticated techniques than the ALE-50. A jamming device called the techniques generator carried onboard the aircraft produces jamming signals that are transmitted by fiber optic cable to the RFCM decoy for transmission. Both decoys are single use systems. Once deployed from the aircraft, the decoy’s tow line is severed prior to return to base. Each aircraft is to carry multiple decoys, so if one is destroyed by enemy fire or malfunctions, another can be deployed. Therefore, substantial inventories of decoys are required to sustain potential combat operations. The services expect that these decoys will improve survivability of their aircraft against radar-controlled threats compared to the current technique of emitting the jamming signals directly from the aircraft. Classified test results show that the ALE-50 towed decoy offers improved effectiveness against radar-controlled threats, including some threat systems against which self-protection jammers have shown little to no effectiveness. Moreover, the future RFCM decoy system is expected to further improve survivability due to its more sophisticated jamming techniques. Recognizing the potential offered by these towed decoy systems to overcome the limitations of using just on-board jammers, such as the ASPJ, the Air Force is actively pursuing the use of towed decoys for its current aircraft. It has done the necessary modifications to add the ALE-50 to the F-16, an aircraft slightly smaller than the Navy’s F/A-18C/D, and to the B-1, a much larger aircraft. The Air Force is also considering use of the RFCM decoy system on the F-15, which will use its existing on-board jammer instead of the techniques generator, and on the B-1, as well as several other aircraft. The Navy plans to equip only its future F/A-18E/F aircraft with a decoy system. The ALE-50 decoy system is to be used by the Air Force on 437 F-16 and 95 B-1 aircraft. In addition to the ALE-50 components such as the launcher and controller installed on the aircraft, the Air Force plans to procure 17,306 ALE-50 decoys to meet operational requirements. The Navy plans to buy 466 ALE-50 decoys. These will be used for F/A-18E/F testing and contingencies after the aircraft’s deployment until the RFCM decoy is available. The ALE-50 program cost is estimated at about $1.2 billion. The Navy’s estimated RFCM cost for its F/A-18E/F aircraft is about $2.6 billion. The Navy’s plan is to procure enough RFCM systems and spares to equip and support 600 of its planned buy of 1,000 F/A-18E/F aircraft. For 600 F/A-18E/F aircraft, the number of decoys to be procured to meet operational needs is 18,000. (These estimates predate the May 1997 decision of the Quadrennial Defense Review (QDR) to recommend a reduction in the number of F/A-18E/Fs.) The future RFCM decoy system is also being considered by the Air Force for its B-1 aircraft, part of its F-15 fleet, and several other Air Force manned and unmanned aircraft. If the Air Force buys the RFCM system for the B-1 and the F-15, which would use its existing onboard jammer instead of the RFCM techniques generator, the estimated cost, including 9,107 decoys, is about $574 million. In contrast with the Air Force, which intends to use decoys to improve the survivability of its current aircraft, current Navy combat aircraft will be at a comparative survivability disadvantage since they will not be provided with a decoy system. In particular, because F/A-18E/Fs will not be replacing all of the C/D models in the Navy/Marine Corps inventory in the foreseeable future, adding a towed decoy system to the F/A-18C/D potentially offers the opportunity to save additional aircraft and aircrew’s lives in the event of hostilities. In the year 2010, more than 600 of the Navy’s tactical fighter inventory objective of 1,263 aircraft will still be current generation fighters such as the F/A-18C/D. This will be true even if F/A-18E/Fs are procured at the Navy’s desired rates of as high as 60 per year. At the post-QDR suggested rate of 48 per year, almost 50 percent of the current generation aircraft will still be in the fleet in the year 2012. DOD and the Navy have done studies to determine whether towed decoys could improve the survivability of the F/A-18C/D. DOD’s Joint Tactical Electronic Warfare Study and an analysis conducted by the Center for Naval Analyses concluded that the addition of a towed decoy system to the F/A-18C/D would provide a greater increase in survivability for that aircraft than any jammer, including the ASPJ. In limited flight testing on the F/A-18C/D, the Navy demonstrated the ALE-50 decoy could be deployed from either a wing station or the centerline station of the aircraft. While the Navy acknowledges that towed decoys can enhance aircraft survivability, it does not consider these flight tests to have been successful because of the following suitability concerns. According to the Navy (1) the tow line can come too close to the horizontal tail or the trailing edge flap when deployed from a wing station, making it unsafe or (2) the tow line can be burned off by the engine exhaust or separated by abrasion if deployed from the centerline station. The Navy’s report on the wing station testing stated that tow line oscillation led to lines breaking on several flights, but did not state that the decoy system was a flight safety risk nor that there was any contact with the horizontal tail or flaps. Concerning the centerline station tests, several tow lines were burned off or otherwise separated from the aircraft by abrasion during maneuvering flights. A reinforced tow line later solved these problems and the Navy is continuing testing on the F/A-18C/D from the centerline station. Based on these test results, the Navy now intends to deploy the ALE-50 decoy from the centerline of the fuselage of the F/A-18E/F. The Navy also maintains that even if the decoy could be successfully deployed from the F/A-18C/D wing or centerline station, for actual operations, it could not afford to trade a weapon or fuel tank on a wing or centerline station for a towed decoy system. Further, the Navy considers modification of the C/D model’s fuselage for internal carriage of the decoy to be unaffordable due to volume, weight, power, and cooling constraints that would have to be addressed. The Air Force has modified a wing pylon to successfully deploy towed decoys from the F-16’s wing while avoiding major aircraft modifications and without sacrificing a weapons station or a fuel tank. The Navy, however, has not done the technical engineering analyses to determine the specific modifications necessary to accommodate a towed decoy on the F/A-18C/D either from the wing or the centerline without affecting the carriage capability unacceptably. Congress has expressed concerns regarding F/A-18C/D survivability. The Report of the Senate Appropriations Committee on the National Defense Appropriations Act for Fiscal Year 1997 directed the Navy to report on the advantages and disadvantages of using various electronic warfare systems to improve F/A-18C/D survivability. In addition, Congress provided $47.9 million in fiscal year 1997 funding not requested by DOD to buy 36 additional ASPJs for 3 carrier-deployed squadrons to meet contingency needs.