A three-year rebuilding effort has emerged after the costly collapse of the US Army-led Aerial Common Sensor (ACS) programme. The need for a common sensor package spanning multiple intelligence disciplines remains unchanged, but the search for a suitable airborne platform starts anew.

ERJ 145

Lessons from the failure of Lockheed Martin’s ACS system – based on the overwhelmed Embraer ERJ-145 regional jet – have at least narrowed the options for selecting the aircraft type that is to succeed the army’s de Havilland Canada RC-7 Aerial Reconnaissance Low and Beech RC-12 Guardrail, plus the navy’s Lockheed EP-3 Aries II.

Lockheed’s contract has been terminated for convenience after an army expenditure of $200 million. The contractor is allowed to recoup additional expenses under the contract terms, but these are expected to be in the tens of millions of dollars.

A six-month analysis now under way is charged with reviewing all potential alternatives, but army officials have identified two main themes of any feasible replacement strategy. Under one option, the programme can continue to depend on the common sensor approach, but that will probably require an aircraft much larger than the ERJ-145. Alternatively, a similar regional jet – or business jet – could be used, but only if some sensor requirements are performed by a secondary fleet of unmanned aircraft.

Introducing unmanned aircraft into the study effort is perhaps the most critical difference from all previous analyses of suitable aircraft for the ACS mission. At the same time, it raises new questions. The US Army and US Navy, with the US Air Force’s participation, must consider whether the ACS mission deserves a new fleet of dedicated unmanned aircraft.

“The question becomes, does it require a dedicated mission of UAVs or can you do the mission using part of an existing UAV fleet?” says Edward Bair, the army’s programme executive officer for intelligence, electronic warfare and sensor acquisition programmes.

The six-month study also will encompass an analysis of other options. The services will investigate upgrading the ACS platform to a larger size or merging the requirement with an existing programme. The navy’s plan to buy 108 Boeing P-8A Multi-mission Maritime Aircraft and the air force’s intent to buy a small fleet of Northrop Grumman E-10A Multi-sensor Command and Control Aircraft (MC2A) are among the primary candidates, says Bair.

Acquisition strategy

The results of the study will trigger a roughly two-year process of defining the terms of the new acquisition strategy and organising funds and the schedule for a new development programme. The army’s plans call for launching a new system development and demonstration (SDD) phase in late 2008 or early 2009, with fielding of the first ACS unit in fiscal year 2016, says Bair.

Terminating Lockheed’s contract leaves the army six years behind schedule in its plan to modernise the heart of its airborne intelligence capability. The army’s vision for ACS was to field a new aircraft that is able to simultaneously collect signals, imagery and measurement and signature intelligence. The ACS mission involves supporting forward deployed forces in the first stages of a conflict, providing real-time geolocation of enemy forces to the battlefield commander.

In August 2004, Lockheed was awarded an $870 million contract to conduct the SDD phase. The army selected the Lockheed proposal over a bid by Northrop Grumman based on the Gulfstream G450 business jet. The G450 is slightly larger than the ERJ-145, but probably would have proven similarly insufficient to meet the ACS requirements. The army signed the Lockheed contract with plans to buy 38 aircraft after the development phase. The navy also planned to join the development phase by the end of 2004, with proposals to buy 14-19 aircraft to be fielded after FY2012. But the navy never formalised its participation, as signs quickly began to appear that the programme faced major difficulties.

Three months after contract signing, Lt Col Steve Drake, ACS programme manager, declared that the “honeymoon” was over for the ACS programme and real progress needed to be achieved. By December 2004, programme officials say, it had become apparent that the ERJ-145 was undersized to support the cooling, power and weight requirements of a sophisticated common sensor package.

The discovery appeared to come as a surprise despite a competitive phase that required the army to scrutinise Lockheed’s plans. An army review panel had looked at Lockheed’s proposal based on the ERJ-145 before contract award, but found no shortfalls.

At least part of the surprise is now blamed on faulty models used for calculating aircraft weight. Progress in miniaturisation in the electronics industry allows designers to insert more processing capability into every mission system “black box” on the aircraft, Bair explains. This trend also dramatically increases the requirements for cooling and power needs, but aircraft weight models have failed to keep pace, he says.

Fundamental differences in how the army and navy intend to perform the ACS mission also contributed to the programme failure. The army plans to fly multi-ship ACS missions at altitudes between 27,000ft (8,230m) and 40,000ft. The navy and air force prefer to perform intelligence missions at stand-off ranges and lower altitude. Flying lower leads to a requirement for self-protection equipment that would not be necessary for the army’s needs alone, says Bair.

By the second quarter of 2005 programme officials had concluded the ERJ-145’s shortfalls could not be overcome without radical changes to the programme, either by scaling back the services’ requirements or switching to a larger aircraft. A few months later, users from both services upheld the original requirements. In September 2005, the army issued a stop-work order to Lockheed, requiring the manufacturer to propose a range of options for the army to consider within 60 days.

After a one-month extension, the army decided that Lockheed’s proposals were still inadequate. The decision was made to terminate the contract and start over with a new competition.

This time, serious attention will be given to the potential contribution of unmanned aircraft. The idea, says Bair, is that the army could leverage the electro-optical sensors and low- to- medium-altitude mission profiles of most unmanned aircraft systems (UAS) to shave some of the requirements off the ACS mission package.

Unmanned aircraft

The army is buying 132 Extended Range Multipurpose (ERMP) un­manned aircraft, based on the General Atomics Warrior UAV, a variant of the Predator family. Another candidate is the army’s AAI RQ-7 Shadow 200 UAV. The US Air Force also is involved in the study, and may recommend the General Atomics RQ-1 Predator A, the MQ-9 Predator B or the Northrop Grumman RQ-4 Global Hawk.


Bair bristles at the suggestion that including UAV in the study was an indicator that the army wanted to offload part of the ACS requirement. “The question isn’t per se what you can offload to them,” he says. “The question is how you integrate them into an airborne [intelligence, surveillance and reconnaissance] capability so you don’t have to invest in redundant functionalities.”


Source: Flight International