Boeing 767-400ER E-10A

Boeing 767 400ER E-10A

For many years now the USAF has operated a variety of Boeing 707 variants in a number of significant ISR roles, as the AWACS, J-STARS and RC-135. All these aircraft platforms incorporate old airframe, engine and avionics technologies that are already becoming increasingly expensive to maintain. Furthermore, given the post-cold war environment and the rise in international terrorist activity, these aircraft are among the most heavily utilised all over the world.

In 2001 the problem how most to most effectively replace these aircraft was one that the then USAF chief of staff, General John Jumper, addressed when he, or most likely someone on his staff, came up with the idea of a Multi-sensor Command and Control Aircraft (MC2A) – a single type of aircraft that ‘could’ undertake all the roles of the current AWACS, J-STARS and RC-135 single-role aircraft. In addition, it was envisaged that the MC2A would also become a flying command post, allowing the US to both plan and execute short-notice air operations without having to rely on ground based operations centres. However, when Jumper first unveiled his idea it was unclear whether he proposed that the USAF spend billions replacing all the 33 AWACS, 17 J-STARS and the 8 RC-135 River Joint aircraft, or whether this was just an example of ‘blue-sky thinking’ intended to galvanise industry to investigate the possibilities of fusing current sensor and C2 technologies.

As this proposal was debated, it was further suggested that the planned aircraft might also be equipped to replace the C-130 Compass Call, RC-135 Combat Sent and RC-135 Cobra Ball aircraft, as well as incorporating some equipment to allow it to assume some of the roles of the U-2S. At around the same time, the US Navy’s requirement of a Multi Mission Aircraft (MMA) was also being considered and there were clearly many advantages in considering the option of using the same aircraft.

Boeing 767 400ER E-10A

In Sep 01, the House Intelligence Committee suggested the development of a single manned reconnaissance aircraft, owned by a joint agency, but operated by both the USAF and USN. The precedent for this type of operation had already been set by the USN, US Marines and USAF use of the EA-6B Prowler, delivering obvious benefits in operational costs and inter-service co-operation. The proposed aircraft would replace the RC-135 and EP-3 fleets with a Boeing 767 sized aircraft, designated the E-10A.

In Oct 02 a study entitled ‘Alternatives for Joint Multi-Mission Aircraft’ identified four possible solutions:

    1. A single aircraft for all missions. This option was judged both too risky and costly and would probably take longer to mature than the timescales allowed in the current USAF / USN plans. This option would probably cost around $189 billion for 176 aircraft.

    2. A single aircraft without a SIGINT capability. This would still cost around $132 billion for 144 aircraft and would still be unlikely to enter service in the timescales necessary.

    3. A joint SIGINT programme to produce a dedicated aircraft. However the 32 planes would still cost $23 billion, a 737 sized aircraft preferred by the USN would be too small to carry all the Rivet Joint systems and would require the USAF to commit to an aircraft a decade earlier than expected.

    4. A common airframe. This would provide 191 aircraft for around $111 billion. However this proposal would probably require the USN to buy a 767 sized aircraft, considerably larger than the 737 sized aircraft they would prefer.

However, neither the USAF or the USN were prepared to compromise their own plans by agreeing to the use of a common airframe and the likelihood of a combined MC2A / MMA appears at best very remote, despite the obvious operation advantages and financial benefits.

After considerable study, a consortium of Boeing, Northrop, Grumman and Raytheon, in consultation with the USAF, proposed the incremental development of the E-10A in a series of ‘spirals’. The first development, known as Spiral One, proposed a Ground Moving Target Indicator (GMTI) equipped aircraft with a ground surveillance, targeting, C2 and battle management capability similar to the J-STARS. The primary sensor proposed for this version would be the Northrop Grumman / Raytheon MP-RTIP high-resolution synthetic-aperture ground surveillance radar, a development of the radar currently used by the Global Hawk UAV, mounted under the fuselage in a long fairing similar to the current 707 J-STARS. The USAF initially received $4.5 billion funding for Spiral One development.

Spiral Two development proposed adding a Air Moving Target Indicator (AMTI) capability, to either the GMTI equipped aircraft or a separate aircraft, providing a greatly enhanced battle management, surveillance, targeting and C2 capability. The primary sensor for this version would be the Northrop Grumman ESSD Multi-role Electronically Scanned Array (MESA), mounted above the rear fuselage similar to the 737 ‘Wedgetail’ AEW&C. Further studies would determine how to develop Spiral 3, a SIGINT E-10A that would replace the Rivet Joint and possibly other RC-135s.

Boeing 767 400ER E-10A AMTI/GMTI

Nevertheless, over the last 3 years as industry began to fully address this proposal, it became apparent that, even allowing for some significant technological developments, it would be impossible to incorporate a combined AMTI and GMTI capability in one airframe within the planned timescale – never mind trying to also include an intelligence gathering capability as well. Such a complex aircraft, with so many systems attempting to transmit energy at the same time, would without extremely clever electronics almost certainly end up simply jamming itself. In addition, it was soon realised that trying to add the Rivet Joint capability, an essentially passively role listening and identifying enemy transmissions, in an aircraft that was itself pumping out huge amounts of radar energy, was to all intents and purposes completely incompatible, given current technology.

Eventually in Nov 02 the USAF dropped the goal of a combined GMTI/AMTI E-10A and instead announced the planned acquisition of two separate fleets of firstly GMTI aircraft followed later by another buy of AMTI equipped aircraft. This decision has puzzled a number of observers who wondered whether it made sense, as the current J-STARS fleet use much newer 707 airframes than the older AWACS and Rivet Joint fleets. However, a USAF representative explained this decision by explaining that the current state of the technology and funding already committed to the MP-RTIP led the service to decide that Spiral 1 would be a GMTI aircraft. It was also felt that the majority of current conflicts do not involve a significant air threat, but require a system that can identify targets on or close to the ground.

Boeing 767 400ER E-10A - interior

Given the problems involved in attempting to combine a GMTI, AMTI and SIGINT capability in one airframe, other options are already under consideration. Northrop Grumman is already attempting to develop a smaller version of the MP-RTIP for their Global Hawk and a SIGINT package has already been flown in this successful UAV. This work could eventually result in two Global Hawks, one equipped as a GMTI platform and the other as a SIGINT platform, operating in conjunction with an AMTI E-10A that could fuse and disseminate the data from all three platforms. As these systems would be linked by data or satellite links, allowing the data to be transmitted back to a ground base anywhere in the world in virtual real-time, known as ‘reach-back’, the next option is whether to station the battle management staff in a secure ground base, rather than actually in the aircraft. Currently the USAF would prefer to have the majority of the staff actually on the aircraft, although I believe that is it only a matter of time before advances in technology, together with the sheer quantity of the data that needs to be fused and filtered from complementary systems, will prove overwhealming. Eventually it may be necessary, as well as more efficient and cost-effective, to have a much larger number of battle management staff interpreting the data than can easily be accommodated within an airborne platform, even an aircraft the size of a 767 E-10A.

Just as the RC-135 has been the USAF’s pivotal ISR platform over the last 40 years, it was planned that the 767 E-10A, in one form or another, would eventually take over the many roles that the RC-135 has performed with such distinction. The technological advances over the last four decades have been enormous and these could allow capabilities considered unthinkable only a few years ago, to be incorporated into one wide bodied twin-engined jet aircraft. Finally, it is possible that, given sufficient research time, technological innovation and resources and, it might even be possible one day to eventually combine a comprehensive GMTI, AMTI and SIGINT platform in a single airframe. Whether the resulting aircraft will be fully crewed with pilots and battle management staff, or simply 3 or 4 pilots and some technicians with very high capacity satellite data links providing the necessary 'reach back', is another question that will need to be addressed at some date in the future

Despite the clear need to plan a replacement for the RC-135 and J-STAR fleets, as each year passed and operational commitments in the Middle East grew, greater pressure was placed on the Defence Budget. In late 2003 Boeing also became embroiled in a scandal regarding an aborted deal to lease 100 KC-767 tankers to the USAF in an attempt to secure the 767 production line. After various cut-backs and restructuring, it was eventually announced in the USAF spending plans for FY2008-13 that the E-10A programme would be killed off completely. However, in the years leading up to this date contracts were awarded to various companies to continue work on developing the Battle Management Command and Control (BM2C) technology, particularly the software, as this system could eventually be migrated across to the existing E-8 J-STARS platform. In addition, a larger version of the wide-area sensor currently being developed under the Multi-Platform Radar Technology Insertion Programme (MP-RTIP) for the E-10A and the Northrop RQ-4B Global Hawk may well eventually replace the SAR/GMTI radar in the E-8 J-STARS.

Prototype E-10A N526BA at Paine Field

Boeing have yet to decide what to do with the 767-4FSER (N526BA) that would have been the prototype E-10A. The aircraft is still based at Paine Field, Everett, Washington and makes the occasional test flight. The aircraft might possibly be converted into a business jet at some date in the future. The E-10A was always going to be a costly programme and perhaps it was a little over-ambitious to hope that advances in technology would enable a single aircraft to replace a variety of single-role aircraft. However, the need to eventually replace the RC-135 and E-8 J-STARS fleets has not gone away, particularly as these aircraft are still amongst the most heavily tasked aircraft in the USAF fleet. Eventually re-engineering old airframes with new engines and life extension programmes just isn’t cost-effective any more and sooner or later this replacement problem will have to be re-visited. However, by the time this happens I suspect the Boeing 767 line will have long shut down and the replacement platform will be based on the Boeing 787 Dreamliner. Nevertheless, before this can happen, the ‘fighter Mafia’ at the top end of the USAF will first have to accept that the F-22 Raptor and F-35 Lightning II are not the highest priority and that in the new environment of the 21st century ISTAR aircraft probably have an even more important role to play than traditional fighter aircraft.

Updated June 2008