I Will Be Your Escort

by Michael Puttré
May. 1, 2002

By the accounts of developers, integrators, and customers - not to mention supporters in the US Congress who write the checks - the Improved Capability III (ICAP III) upgrade for the EA-6B Prowler is a new lease on life for the venerable electronic-attack aircraft. While action in Afghanistan has underscored the US requirement for a carrier-borne, full-spectrum, electronic-attack capability; it was the 1999 NATO campaign in Kosovo that demonstrated both the necessity and pitfalls of the Prowler and its mission.

The good stuff first: Faced with a requirement of providing escort jamming for stealth strike aircraft - the F-117 and the B-2 - in addition to more conventional platforms, the US Air Force was chagrined on two counts. One, stealth is not a cloaking device. Although the more sober term "low observable" had been in the vernacular for some time, some Air Force officials clearly enjoyed the mystique of their exotic, expensive black planes.

The need to escort these ultra- modern aircraft with rickety old crates making beeps and squeaks brought more than a few grins from Long Island, home of the Prowler. Two, having retired their EF-111 Ravens, peaked hat in hand, the Air Force had to approach the Navy and Marine Corps to provide indispensable escort- jamming services. Of course, this could also be spun as an example of inter-service cooperation at its finest. In any event, the Prowler escorts had full dance cards.

The bad news was the Prowler demonstrated that it was not a particularly cooperative aircraft in what was supposed to be a coalition war. In an exclusive interview, Major Thomas Emig of the German Air Force Command and a Tornado electronic-warfare officer (EWO) said that German ECR Tornados on suppression-of-enemy-air-defense (SEAD) missions in the Kosovo conflict often were unable to identify enemy radar and SAM sites due to the effects of Prowler jamming. Thus, the HARM-armed Tornados were not able to fulfill their missions.

While many of the problems could be addressed with more cooperation between coalition air services during mission planning, the fact is that Prowler operations by their very nature impose limitations on who can fly other missions when and where. Currently, Prowler operators are capable of spot-jamming selective frequencies of known threat emitters. However, more mobile air-defense systems that use sophisticated, frequency-agile sensors are capable of staying ahead of operator-controlled spot jamming, leaving barrage jamming of the RF spectrum as the only viable alternative, and once again we are sharing a back seat with the frustrated Tornado EWOs of Kosovo.

Clearly, escort jamming is needed for air forces that seek to penetrate opposed airspace. Also needed is an alternative to indiscriminate, broadcast-based jamming, which, in addition to rendering many strike aircraft impotent bystanders, has the effect of telegraphing the intention and possibly even the direction of a raid. These are the sorts of issues that ICAP III is supposed to address. Escort jamming as a mission is alive and well, and it can be done better than it has been in the past.

A Feather in ICAP

According to Sam Abbate, ICAP III program director and integrated product team leader at Northrop Grumman (Bethpage, NY), ICAP III enables selective reactive jamming, in which the AN/ALQ-99 jammer hops around on different frequencies with the target radar. ICAP III's AN/ALQ-218 dual receiver (formerly designated the LR-700) has a broadband primary receiver that searches the entire RF spectrum and an auxiliary receiver that focuses in on specific frequencies. The ALQ-218's controller is extensively software driven, and software development is occupying most of the unfinished work in preparation for operational assessment of the first two ICAP III Prowlers later this year. In a separate activity, the ALQ-99 jammer's transmitters are being upgraded by BAE Systems (Nashua, NH). In addition, the Universal Exciter Upgrade being carried out by EDO Corp. (Deer Park, NY) is extending the frequency coverage of the ALQ-99 and incorporating advanced jamming techniques.

Coupled with advanced threat libraries and pre-mission data-load files tailored to the threat environment, the system is expected to automatically detect and track emitters and provide the correct jamming response. If the threat emitter is frequency agile and starts hopping around, the ICAP III is designed to hop with it. "This capability allows ICAP III to attack more emitters in the environment by applying power more selectively and also be more discrete about the way it operates in that environment," Abbate said.

The ICAP III retains the Prowler's primary mission as a radar-jamming platform, covering a more current threat environment. Furthermore, ICAP III is still an escort jammer, intended to penetrate with the strike force. Nevertheless, improved capabilities are suggesting other roles. The combination of the ALQ-99 transmitter pods and the Rockwell Collins (Cedar Rapids, IA) AN/USQ-113 comm jammer - first deployed just in time for the air war over Yugoslavia - was important over Afghanistan, where Prowlers reportedly did a fair amount of communications jamming. Increased frequency coverage and long-baseline interferometry also enable the ICAP III to target emitters by geolocation, which gives it a much greater targeting capability for its own HARM anti-radar missiles and for other strike assets. Geolocation, where the aircraft is receiving target-quality data from threat emitters without broadcasting its presence, represents something of a new mission for the Prowler, although its signals-intelligence capabilities are well known, if not widely reported. "ICAP-III has a 360-degree field of regard with respect to detection, and very good fore and aft long- baseline interferometry," said John Young, Northrop Grumman's vice president and integrated product team leader for EW systems.

Mission creep is increasing the Prowler's need to communicate more closely with other assets in the theater of operations, and possibly beyond. In terms of connectivity, Northrop Grumman is implementing provisions for Link-16/MIDS [Multifunction Information Distribution System], although there is a separate contract that puts Link-16 in place. The inclusion of Link-16, although programmatically outside of ICAP III, is important because it represents a broadband datalink that will allow the aircraft to cue other assets either to perform jamming or a strike mission, if a given Prowler chooses not to let one of its HARMs go. It will also vastly expand the universe of aircraft with which the EA-6B can share data.

Inside the four-place cockpit, ICAP III is integrating a number of capabilities that currently are handled by discreet systems and crew stations. The Multimission Advanced Tactical Terminal (MATT) and an improved data modem, first installed under the ICAP II Block 89 program beginning in 2000, added provisions for satellite communications (SATCOM) that enabled the Prowler to share HARM- targeting data with similarly equipped Prowlers, Rivet Joint aircraft, and ideally with F-16CJs. But this was not an integrated function. "Right now, Prowler crews use a ruggedized laptop computer to work the SATCOM data," said Abbate. "Somebody literally sits in the back cockpit with a computer in their lap. It is not tied into the system at all. The only tie-in is the intellectual capacity of the operator. And obviously, a Prowler cockpit is not a great environment to have a loose object."

On that note, ICAP III integrates the USQ-113 communications jammer, which today also requires a separate panel as a dedicated crew station - and the laptop. Integration of the MATT, the data modem, and the USQ-113 will enable all of these systems' functions to be accessible on new 8x10" color multifunction displays in each crew station, including the pilot's. Currently, the pilot just drives the bus. "The added pilot display will enable him to take on selective roles, which have not been determined yet," Abbate said. "But the concept is once the aircraft is launched and is on station, the pilot can contribute to the EW mission."

It is very interesting to note that the development of operational concepts for improved Prowlers does not appear to have kept pace with the technical developments, which, it must be said, have not been especially hurried to market. "The specific CONOPS [concept of operations] of how the Navy will function with ICAP III is still to be determined, because they haven't really wrung it out in a wargame environment," Young said. "The three significant attributes at the core of ICAP III: passive geolocation for accurately finding a spot on the geodetic world sphere; rapid response time for jamming, firing a HARM, or handoff to another asset on the network; and connectivity to enable the handoff will be the keys to its warfighting capability. We're not sure how they are going to use it yet from a CONOPS standpoint, but those attributes will certainly be employed."

Still a topic of debate in the fleet is how many Prowlers will be retrofitted to the ICAP III configuration. The lack of a firm CONOPS is probably contributing to some of the uncertainty. That, and the always-mercuric attitudes about EW-program funding. Estimates are that somewhere between 50 to 120 Prowlers will eventually be ICAP IIIs, both Navy and Marine. Given the Pentagon's penchant for treading water, particularly with the Analysis of Alternatives (AOA) review of a Prowler replacement underway, the lower end of that spectrum seems likely.

Growling For Dollars

The ICAP III program also plays a significant - if not the deciding - role in determining the fortunes of the EA-18 electronic-attack variant of the F/A-18F Super Hornet being proposed by Boeing Military Aircraft (St. Louis, MO) and partner Northrop Grumman. Boeing has led the development of an EA-18 (previously dubbed the F/A-18G "Growler") demonstrator with its own money and an aircraft leased from the US Navy. The aircraft would be capable of carrying the ALQ-99 jamming pods on its centerline and under-wing stores stations and the ALQ-218 receivers on specially designed wingtip pods. The Navy is clearly interested in the concept, and Boeing is banking on spinning that interest into contracts. To increase the appeal of its horse in the AOA race, the company is stressing the high-performance capabilities of the EA-18 and the more aggressive missions these suggest.

Late last year, Boeing completed its first flight-test program, where it got the demonstrator aircraft equipped with mock pods to 0.8 Mach and about 18,000 feet. "The data showed that we were well within the noise and vibration envelope of the ALQ-99 pods as loaded," said Paul Summers, Boeing's director of F/A-18 derivative programs. "We saw nothing to indicate that we shouldn't go further. Our plan this year is to get transonic with the pods. We'll go to about 0.9 Mach and up to 30,000 feet."

In addition, Boeing has started to do an analysis with BAE Systems that looks at whether or not the electronics would be able to operate in the aerodynamic environment under the Super Hornet. Summers reported that the analysis has shown very positive results. "So far, they don't predict a problem," he said. "As we get more data from our flight analysis, we are feeding them directly to BAE Systems so they can continue to matriculate their computer analysis."

In the conventional jamming mission, there really is no need to have transonic or supersonic capability. However, in Boeing's vision of the future, the EA-18 will have performance compatibility with the strike assets. Having an electronic- attack capability that can match the speed and endurance of the strikers is seen as essential because the escort aircraft will have to handle "pop-up" threats in time to do the strikers some good at ranges where Prowlers fear to tread. Such a capability would also be important if the Navy chooses to use this aircraft in the Wild Weasel role.

"You can envision a loadout where you will have one jamming pod on centerline -- maybe to suppress SA-6s, for example -- and weapons on all the other stations," Summers said. "We spend our weapons in the standard Wild Weasel role, and then we want to do a dash to get out of there quickly. We believe that you need transonic or Mach capability. Although this is not part of any formal CONOPS the Navy has shared with us yet, we believe that, when they get a hold of this airplane, they're going to want to use it like that."

In mid-April, at press time, Boeing was scheduled to hang a F/A-18E in the anechoic chamber at Patuxent River with ALQ-99 pods radiating on the airplane to do electromagnetic systems-compatibility testing. Summers said that Boeing is looking at ways to use the self-protection suite with the jamming suite, exploring techniques such as blanking. Such a capability would be essential in the aggressive posture that is the Growler's raison d'etre. "Although we don't anticipate flight testing that kind of demonstration on our own funding, as that's going to be a fairly substantial effort and would have to be done under contract during system development and demonstration," Summers said. "What we are doing is an analysis on a position that would support the use of those assets together."

Back Off

Of course, the United States today is just about the only country that can afford scores of dedicated electronic- attack aircraft and the cast of thousands of highly trained experts who support them. "The US has specialized EW aircraft that cover an area and so take some of the burden off the strike aircraft in terms of self- protection." said Dov Granot, business development manager for the Elisra Group (Bene Beraq, Israel). The Israeli Air Force favors a system where select aircraft in a strike package are equipped with escort- jamming pods. "Israel's philosophy is that an aircraft needs to be able to protect itself from start to finish, from take-off through landing."

Jean-Philippe Gourion, deputy director of strategic planning for Thales Airborne Systems (Paris, France), said Thales is working on an escort-jamming concept in which dedicated platforms and crews would be replaced by a combination of integrated systems featuring a solid-state, phased-array jammer with very high transmitted power and real-time multi-beam steering. This would be fitted in an automatic pod carried by a multirole fighter for the stand-in/escort jamming mission. Since 1993, Thales has been developing its Carbone offensive jammer demonstrator under contract to the French military procurement agency. According to Gourion, the Carbone is significantly more powerful than existing or upgraded offensive-jamming pods. Carbone also draws on Thales' digital receivers and real-time geolocation algorithms, such as those implemented in the Spectra EW system for the Rafale aircraft.

The Carbone demonstrator has been mounted on a Mystere 20 testbed aircraft and has flown extensively since 1998, including during the NATO MACE X field trials in August 2000. A preliminary study for a pod installation has been through cost-assessment and risk- reduction studies. "Operational trials have demonstrated Carbone's effectiveness, and particularly its capability to jam through scattered lobes." Gourion said. "This is a big change in the strategy of the use of such equipment."

A fighter aircraft carrying a pod-mounted phased-array jammer would have the ability to loiter at the periphery of the threat area, but not necessarily in line with the flight path of the strikers. Once the strike package is about to enter the threat area the electronic attack aircraft is alerted by datalink to commence jamming through the secondary or scattered lobes of the threat emitters. Thus, the enemy would remain unaware of the direction of the strike package's arrival. Gourion pointed out that there would be some burden during the mission-planning phase to ensure that timing, waypoints, and jamming duration are synchronized. "In fact, if your mission planning is excellent, then you are not obliged to use a datalink or otherwise transmit between the strikers and jammer aircraft," he said.

Another benefit of this approach to stand-in/escort jamming is that the electronic-attack aircraft does not have the same demands on its self-protection jammers, thus eliminating the potential for interference. In fact, Gourion questioned the wisdom of even attempting to operate electronic-attack and self- protection systems on the same aircraft at the same time. "Frankly speaking, I don't think that it would be a very good idea to use stand-in jamming tactics other than those that attack side or scattered lobes at some distance," he said. "If the electronic-attack aircraft is loitering at very low altitude somewhere in a relatively safe place quite close to the danger zone, then you can decide at a given instant to pop up and begin your jamming job."

But if you have to stay in the high- threat area, Gourion continued, it would be much more preferable to use a UAV as a stand-in platform, loitering at very high altitude -- say, over 50,000 feet. The very same selective-reactive technologies that automatically detect, track, and provide the correct jamming response to threats in ICAP III conceivably also make it possible for the EWO to be snug in a command shelter hundreds of miles away, monitoring the proceedings via SATCOM with a cup of coffee. Try that in a cockpit.