FLUG REVUE March 2003: Prowler successor sought

PROWLER REPLACEMENT SOUGHT

By Karl Schwarz

Suppression of enemy air defences (SEAD) has been one of the standard tasks of the US armed forces since the Vietnam War. To minimise losses, as the public demands, offensive missions are no longer launched today without the support of jamming aircraft and an anti-radar capability. This requirement imposed limitations on the flexibility of the planners in the Kosovo war in 1999, as Northrop Grumman EA-6B's were not available in the numbers needed.

EA-6B Prowler

In Afghanistan the threat may have been significantly lower, but since the retirement of the US Air Force's last EF-111's in 1998, it has fallen to the Prowlers to bear the main burden of escorting attack aircraft. No mean task for the elderly planes, whose average age has risen to 20.5 years. The large number of missions they have been required to fly has also taken its toll. Out of a pool of 122 aircraft, only 65 were still fully available last summer – far too few to satisfy operating and training requirements.

Some members of Congress' Electronic Warfare Working Group therefore fought doggedly for more money to rectify rapidly a whole series of serious shortcomings:

Fatigue problems in the wing centre section mean that 40% of all Prowlers are limited to manoeuvres entailing no more than 3g, and eight have already been grounded. Although Northrop Grumman has been awarded contracts to upgrade 35 aircraft so far, the work is proceeding relatively slowly.
New jamming transmitters are needed for the frequency bands 9/11. 236 is the target number, but so far only 220 have been ordered, which complicates training. Continued use of the old Band 9 transmitters is creating extra work for maintenance crews.
J52 engine: damaged bearings in the turbine section caused two crashes in November 1991. 88 of the 360 existing Pratt & Whitney J52's were therefore deemed not airworthy last September. The repair programme (replacing the roller bearings for more durable components) has advanced more slowly than the target number of 20 engines per month, due to lack of finance.
Oxygen system: the EA-6B is still not fitted with an On-board Oxygen Generation System (OBOGS). On the significantly longer missions that are customary today, the liquid oxygen tanks have therefore frequently been exhausted prior to landing.
USQ-113(V3) jamming transmitters: hostile forces have recently been making increased use of mobile phones and other non-military communications systems to co-ordinate air defence, but only 35 of the USQ-113's developed by Rockwell-Collins are available to disable these networks, far fewer than are necessary.

However, rectification of these vulnerabilities would bring only short-term relief, as the Prowlers are up against ever more powerful air defence systems. According to the US Air Force, Russian exports of equipment such as the S-300 and S-400, with their extremely long-range missiles, constitute an increasing threat. Again, radar and missile launchers are becoming more mobile. If the various radars and other sensors can be networked, the result is a better situational display. This in turn means that individual radars do not need to be switched on for so long, making them harder to detect.

According to the Defence Intelligence Agency, during the entire operation Allied Force in 1999 the US forces did not succeed in ever entirely closing down the skilfully deployed Yugoslav air defences. Despite thousands of missions to protect the fighter bombers, one supposedly "invisible” F-117 was even lost.

To equip the EA-6B for the new challenges, Northrop Grumman has been developing the "Improved Capabilities (ICAP) III” system since March 1998. This programme, originally launched with a budget of $144 million, had to be restructured in May 2000 due to problems with the software and the new receiver, and will now cost around $200 million.

At the heart of ICAP III is an upgrade of the jamming system, in particular installation of the digital LR-700 receiver. This will make it possible to evaluate enemy signals far more accurately and to provide "reactive” jamming, i.e. no longer will energy simply be radiated over a broad spectrum, but only the relevant frequencies will be prosecuted. It is especially important here that the system is in position to keep up with the frequency hopping employed on many radars.

Other elements of the modernisation programme are:

A new central mission computer.
New displays. Liquid crystal screens with a Windows-like user interface are to replace the antiquated monochrome displays.
A mission re-programming unit with digital storage of mission data is to replace the old cassette recorder.
Integration of the USQ-113 countermeasures system.
A powerful datalink for the effective exchange of information with other aircraft, especially the F-18 Hornet.

The first ICAP III equipped Prowler had its maiden flight on 16 November 2001 in St. Augustine, Florida and began an intensive test programme on 21 November in Patuxent River, Maryland. The second aircraft followed in June 2002 after some delay, as it had to first be fitted with a new wing centre section.

Upgrading of the EA-6B to the ICAP III standard will now commence in 2005. By 2010, all the Prowlers should have been fitted with the new systems. But by that time they will not be far off from retirement, which is planned to be complete by 2015.

Already by 2008/2009 it is likely that there will no longer be enough Prowlers to keep all the squadrons operational. It would seem that development of a successor is essential, yet the Pentagon appears to be having trouble getting its act together.

Under the auspices of Congress's General Accounting Office (GAO) the American Department of Defense carried out a $16 million study that was completed in December 2001. However, the 2,000-page thick "Airborne Electronic Attack Analysis of Alternatives” contained performance and cost details on no less than 27 alternatives and avoided coming out with any specific recommendation.

"The analysis does not provide any basis for a balanced, comprehensive strategy for covering all the requirements of the Department of Defense with regard to the suppression of enemy air defences. For example, it does not cover improvements in electronic self-protection systems or in air-launched decoys,” complained even the GAO in a new report published in November 2002.

In any case, the study enabled the Services to back off from a uniform solution and to continue to stick with their preferred projects. On 4 June 2002 they presented their proposals to Edward "Pete” Aldridge, Pentagon Undersecretary of Defense for Acquisition. He seemed not entirely convinced, but evidently did not intervene decisively.

As a result, the US Navy apparently applied further pressure for funds to develop the Boeing EA-18 "Growler” in the next budget, receiving strong backing from some members of Congress. Up to $4 billion is likely to be required between 2004 and 2008.

Boeing and its partner Northrop Grumman have still not signed a contract, but according to a spokeswoman at the St. Louis, Missouri factory, preliminary work is currently under way as part of a Pre Systems Development and Demonstration contract, which has a budget of $5 million. The actual development phase could begin in October 2003.

In the view of the manufacturer, the technical risk is low, so deliveries could start in 2008. Meanwhile a number of privately funded trials have already been carried out in the last few years, including wind tunnel tests and a review of the electromagnetic compatibility of the jamming transmitter with the avionics of the F/A-18F Super Hornet.

A first flight test took place on 15 November 2001, and four further flights were carried out last year. Flights were carried out up to an altitude of 9,150m and velocity of Mach 0.9 with a payload of three ALQ-99 jammers and two auxiliary tanks. According to programme manager Paul Summers, the results were extremely promising.

The EA-18G is to be fitted with the Prowler's ICAP-III electronics. The used jammer pods are not a problem, but, for example, the digital receiver needs to be repackaged so that it can be accommodated in front of the cockpit (where the cannon ammunition is presently located). Operation of the system, which is to be manned by a crew of two instead of four as on the EA-6B, will require further automation. 450 crew members have already been filtered through a simulator in St. Louis and consulted as to their preferences.

As Summers concedes, integration of the jammer systems may not be child's play, but "there is no more mature concept”. As far as the Navy is concerned, the EA-18's have the additional advantage that one more maintenance-intensive type will disappear from the carrier deck. Whereas the EA-6B costs $19,000 an hour to operate, the equivalent figure for the EA-18G will be only $7,400.

This business will be especially welcome to Boeing after its defeat in the JSF competition. If the US Navy goes it alone, 90 aircraft will be built, at a unit price of around $57 million.

Whereas the US Navy has a conventional, but clear picture of its future EW aircraft in mind with the EA-18, the US Marine Corps evidently wants to keep its Prowlers in service as long as possible and then convert to an Electronic Attack version of the F-35. This would not be available until the next decade and might also not be a vertical takeoff aircraft.

The ideas of the US Air Force, which can still equip some 220 of its F-16 Fighting Falcons with HARM targeting pods to knock out hostile radars, are even more diffuse. General John Jumper, Chief of Staff, said last year that the top priority was not the jamming system platforms but the necessary effects. Ideas range from equipping the B-52 with jamming transmitters through to deploying drones and improved electronic self-protection for fighter bombers. But until these ideas have been fully fleshed out, funding is unlikely to be forthcoming. In any event, the USAF will continue to be dependent on its over 30 year-old Prowlers for many years to come.

From page 42 of FLUG REVUE 3/2003

Last updated 15 February 2003

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