What follows is extracted from “Airborne Electronic Warfare: Issues for the 107th Congress,” a 26-page paper released Feb. 9 by the Congressional Research Service of the Library of Congress. The principal author is Christopher Bolkcom, a CRS national defense analyst.
Electronic Warfare has been an important component of military air operations since the earliest days of radar. Radar, EW, and stealth techniques have evolved over time as engineers, scientists, and tacticians have struggled to create the most survivable and effective air forces possible. …
The downing of an F-117 Nighthawk in the 1999 conflict in Yugoslavia by a Serbian surface-to-air missile illustrates that the struggle for control of the electromagnetic spectrum is an ongoing endeavor for US air forces.
Operation Allied Force may be an important watershed in the debate over current and future US airborne EW. It appears that every air strike on Serbian targets was protected by radar jamming and/or SEAD [Suppression of Enemy Air Defenses] aircraft. ECM [Electronic Countermeasures] self-protection systems such as towed radar decoys were credited with saving numerous US aircraft that had been targeted by Serbian SAMs.
Gen. Wesley Clark, the operation’s military leader, described how critical a role EW played in the allies’ success. He testified that “we couldn’t have fought this war successfully without the EA-6B contribution. We really need the Electronic Warfare capacity that we have there.” The value of the F-16CJ SEAD aircraft was also widely touted.
[The 1970s-vintage Navy/Marine Corps EA-6B Prowler is currently the US military’s sole tactical radar-jamming aircraft. USAF assigns crews (pilots and EW officers) to serve in five joint Navy/Air Force Prowler squadrons. USAF has equipped F-16C aircraft with High-speed Anti-Radiation Missiles for the SEAD mission-designating them F-16CJs.]
Table 1 suggests the impact of EW and SEAD on NATO aircraft survivability during the Kosovo campaign. By using this metric, one can assert that DOD’s EW and SEAD efforts effectively protected US aircraft from Serbia’s integrated air defenses. Yet, despite the low number of NATO aircraft destroyed during Allied Force, concerns have been raised over a number of EW and SEAD issues.
Few and Overworked
In the area of Electronic Attack, the main concern raised by the Kosovo conflict is that DOD currently has too few jamming aircraft in its inventory to support more than one conflict simultaneously. Although Allied Force was considered by many to be a small-scale contingency, [an Oct. 14, 1999, Pentagon statement said that] “US systems such as RC-135 Rivet Joint electronic intelligence aircraft and EA-6B tactical airborne Electronic Warfare aircraft were employed in numbers roughly equivalent to those anticipated for a major theater war, and even then were heavily tasked.” Further, the number of aircraft that could be fielded at any one time may have been unnecessarily decreased by several operations and maintenance shortfalls-such as a shortage of spare parts and too few aircraft trainers. Also, the effectiveness of jamming aircraft may have been degraded by their lack of key technologies such as night vision devices and advanced communications. Finally, experience in Allied Force suggests that the Electronic Attack community would benefit from additional training and experience in supporting Low Observable aircraft.
There are 235 F-16CJs in the total active inventory, and this number appears to have been sufficient to adequately pursue the SEAD mission in Kosovo. However, Allied Force did suggest some numerical shortfalls that may have hindered SEAD operations. According to the commander [Col. Daniel J. Darnell] of the Air Force’s 20th Fighter Wing, the lack of HARM Targeting System (HTS) pods (a key system on the F-16CJ) in Kosovo may have reduced the Air Force’s ability to generate SEAD sorties. “In Allied Force, there were more F-16 aircraft capable of carrying the pod than there were pods to go around.” He also said that a lack of personnel also limited SEAD operations.
Perhaps a greater SEAD concern [in] Kosovo was the great difficulty US forces had detecting, tracking, and destroying Serbian SAMs that minimized their radar emissions or used “shoot and scoot” tactics. Part of the challenge is that the primary SEAD weapon, the HARM, quickly loses its guidance once an adversary turns off his radar, even for a short period of time. A compounding problem is that the targeting cycle for mobile SAM sites takes too long. …
Secretary of Defense [William S.] Cohen and Chairman of the Joint Chiefs of Staff [Gen. Henry H.] Shelton stated in their Kosovo after-action report that the United States must reduce the time between detecting targets and attacking them. The difficulty of destroying Serbia’s SAM launchers can be derived by looking at a different set of Allied Force numbers [as arrayed in Table 2].
This inability to destroy Serbia’s SAM launchers is particularly worrisome because, according to Cohen and Shelton, “the FRY (Federal Republic of Yugoslavia) air defense systems did not represent the state of the art. Much more capable systems are available for sale in the international arms market. In the years ahead, we may face an adversary armed with state-of-the-art systems, and we need to prepare for that possibility now.”
Despite these perceived shortcomings, forces involved in Allied Force employed their aircraft and refined tactics in ways that may hint at future solutions to the problem of destroying elusive SAMs. For example, the Air Force paired different variants of the F-16 aircraft together to exploit their various strengths. Like the HARM, the F-16CJ’s sensors are optimized to find and attack radiating radars. Also like the HARM, the CJ has difficulty finding and targeting the radar if the adversary is careful to limit its emissions. The F-16C/D Block 40, however, has an all-weather precision strike capability and carries laser-guided bombs. By using their data link capability, F-16CJ pilots in Kosovo passed bearing information on SAM radar sites from their HTS to Block 40 F-16s. The Block 40 aircraft were then able to launch precision guided munitions at the fleeting and nonemitting targets. …
This experience suggests to many observers that rapid target detection, identification, and geo-location will be important to the success of future SEAD missions.
The primary topic of ECM-related conversation following Allied Force was widespread praise of towed radar decoys. Although they did not debut in Kosovo, towed decoys were used more pervasively in this conflict than in the past. These ECM were credited with saving several aircraft, such as the B-1B bomber, from Serbian SAMs. Some have described towed decoys as “one of the key enablers of [the Allied Force] bombing campaign.”
However, there were ECM deficiencies as well as successes. The ALE-39 countermeasures dispenser, for instance, was not sufficiently reliable. The ALE-39–which is found on [US Navy and US Marine Corps] EA-6B, F-14, F/A-18, and AV-8B aircraft–at times did not dispense countermeasures (flares or chaff) when it was supposed to. Conversely the dispenser also ejected countermeasures without prompting, leaving the pilot with none available when they were needed.
The ALQ-126 self-protection jammer’s performance was also found unsatisfactory during Kosovo. Navy and Marine Corps aircraft that used this jammer–F-14s and F/A-18s–were not allowed to fly over land where the most hostile threats were located. Only those Navy and Marine Corps aircraft protected by more modern jammers were allowed to fly these missions.
Allied Force flight operations also suggest that passively guided SAMs are a self-protection concern that may merit close scrutiny. Shorter range SAMs can exploit infrared or electro-optical guidance to target low-flying aircraft. Because these missiles do not emanate radar signals, they are difficult to detect. When asked which surface-to-air threat concerned him most, one Marine Corps officer replied, “The unobserved missile.”
Air forces that must fly at low altitudes-such as Army helicopters and special operations forces-have been forced to focus on this threat and are seeking to develop effective countermeasures. Aircraft that don’t have to fly low, often reduce this threat by flying high. Allied air forces in Kosovo were able to reduce much of the threat posed by shorter range surface-to-air systems by flying at altitudes above 15,000 feet. But large transport aircraft that need to deliver men and material to the theater are vulnerable to short-range SAMs. It was reported that “during Operation Allied Force, … Yugoslav anti-aircraft threats forced AMC [Air Mobility Command] planners to sometimes choose less efficient air routes for AMC aircraft to ensure crews’ safety.”
In the aftermath of Kosovo–where EA assets played an important role–the decision to retire the Air Force’s EF-111 Raven and to give responsibility for airborne radar jamming to the Navy and Marine Corps has been questioned in the press, defense academia, and government. The Air Force has also questioned its current footing in Electronic Attack and has revamped its overall policy, doctrine, and budgetary positions on EW. On July 7, 2000, for instance, the Air Force’s highest ranking officers held an “EW Summit.”
Many of the Air Force’s recent activities have been organizational changes that may greatly affect the service’s Electronic Attack capabilities in the mid- and long term. For example, the Air Force has created a new organization on the Air Staff–called XOIE–to more effectively develop and coordinate operational EW requirements. This office, in turn, has developed an EW roadmap and action plan that will address the balance between current systems and future technologies. The Air Force has also established EW offices in its major commands … to better rationalize EW resources and priorities across all programs.
In November 2000, Chief of Staff of the Air Force Gen. Michael E. Ryan announced his new position on EW: “USAF is committed to a support jamming capability adequate to sustain the AEF [Aerospace Expeditionary Force] and joint air, ground, sea, and space operations across the spectrum of conflict. To fulfill AEF CONOPs [Concepts of Operations], the Air Force will define adequate AF EW force structure required to meet projected AEF deployments.”
In addition to these organizational changes, the Air Force has also embarked on activities designed to improve, more immediately, their EA capabilities. For instance, the Air Force continues to maintain its only EA asset, the EC-130H Compass Call. The Air Force has an inventory of 14 of these communications jamming aircraft. According to the Air Force, the Compass Call “has achieved some significant performance advances as part of several classified upgrade programs” over the past several years.
The Air Force is also working on improving its ability to combine LO [Low Observable] and EW operations. According to XOIE officials, at least two combat training exercises have been conducted at Nellis AFB [Nev.] in the post-Kosovo time frame which were designed to improve the integration of EA and LO platforms. Also, general officer-level coordination meetings have been initiated in the Pentagon to address EA and LO training and infrastructure needs. General Ryan has stated that “USAF believes that a combination of EW and Low Observables are required to assure air superiority in the 21st century battlespace.”
Air Force planners have taken a fresh look at SEAD capabilities in the post-Kosovo era. As directed by the aforementioned EW Summit, Air Combat Command has developed a Concept of Operations called “Countering Air Defenses,” or CAD. This document is intended to serve as the foundation for improving the Air Force’s SEAD capabilities. Air Force personnel describe CAD as the most comprehensive document of its type ever written by the Air Force.
The Air Force has also led training activities designed to improve SEAD capabilities. For instance, USAF hosted a joint SEAD test and evaluation at Nellis Air Force Base in August and September 2000, designed to update and test SEAD tactics. The Air Force also annually runs Joint Expeditionary Force Exercises. The one held Sept. 11-14, 2000, at Nellis focused on improving time critical targeting capabilities, such as destroying SAMs that employ shoot-and-scoot tactics.
The Air Force is engaged in a variety of programs to improve its SEAD capabilities. Perhaps the most prominent are upgrades to the HARM Targeting System, the Advanced Targeting Pod, and the Miniature Air Launched Decoy.