Platform May Be the Key to Aerial Common Sensor Decision

Sea Power, Apr 2004 by Burgess, Richard R

In an age of sophisticated warfare systems, the platform - a ship, aircraft or vehicle - is considered merely a "bus" that moves its mission sensors or weapons to the area of operations.

However, in the competition to develop and build the nextgeneration airborne intelligence, surveillance and reconnaissance (ISR) system for the Army and Navy, the performance qualities of the "bus" may be as influential as those of the sophisticated sensors within. Competitor teams for the contract, headed by Lockheed Martin and Northrop Grumman, propose aircraft with fundamental differences in speed, range, payload and national origin.

The ISR plane, called the Aerial Common Sensor (ACS), is being designed to replace several existing aircraft, including the Army's RC-12/RU-21 Guardrail planes and the Navy's EP-3E long-range, land-based electronic reconnaissance aircraft. The Army's Program Executive Officer for Intelligence, Electronic Warfare and Sensors will select one industry team to proceed with a 66-month system development and demonstration phase to cost $680 million through fiscal year 2009. The selection may come as early as this month. Initial operational capability of the ACS is scheduled for 2009.

The ACS concept is to incorporate a broad spectrum of sensors into one platform, including electro-optical and infrared sensors, synthetic aperture radar, electronic intelligence and communications intercept receivers, and a moving target indicator. The data collected could be processed on board the aircraft by the mission crew or linked to other platforms or the Distributed Common Ground Station, a deployable processing station for sensor data downlinked from airborne ISR platforms.

The aircraft will operate at altitudes above 37,000 feet, fly at speeds in excess of 400 miles per hour and conduct mission profiles of eight or more hours with an internal mission/crew payload of about 14,000 pounds. The ACS must be deployable anywhere in the world within 72 hours and sustain operations for 30 days with minimal support.

The Army plans to field 38 ACS aircraft between fiscal 2008 and 2017 at a cost yet to be determined by the Department of Defense, according to Army spokesman Tim Rider. In addition to the aging Guardrails, the ACS is to replace the service's RC-7 Airborne Reconnaissance-Low aircraft fleet.

The Navy's concept of operations indicates a requirement for 14 to 19 ACS aircraft. Initial deployment for the Navy is planned for fiscal 2012. The first two aircraft will be acquired in 2008, followed by two more in 2009.

The Navy has not yet released an estimate of the cost of its participation in the program, but has requested $24.9 million in research, development, testing and evaluation funds for fiscal 2005.

The service has been involved in the ACS program since last year as an interested partner and will formally join it after an Interim Program Review scheduled for October or November.

Navy Capt. Steve Eastburg, program manager for the ACS at the Naval Air Systems Command, said the service conducted a "requirements reconciliation" and "found very little difference" between the operational requirements of the Army and Navy. The only significant change needed by the Navy was to increase the mission crew stations in the aircraft from four to six. This was done to ensure that enough crewmen were available to provide direct threat warnings while monitoring enemy air-defense and antishipping environments likely to be encountered in air and naval operations.

The Navy currently flies 11 overworked EP-3Es and is in the process of converting five more P-3C patrol aircraft to the EP-3E configuration to allow for a fleet of 16, including 12 operational aircraft and four for maintenance or modification. Replacement of the EP-3E fleet by the ACS would be completed by fiscal 2014.

With a crew of only two pilots and six sensor operators, the ACS will operate under a different concept of operations than the EP-3E, which carries a crew of 24. A higher degree of automation in digital signal processing in the ACS will allow the crew to handle the on-board sensor analysis workload. In addition, the ACS will be able to transfer data during the mission to ground and ship stations for analysis and fusion, allowing more thorough analysis by intelligence centers and therefore requiring fewer analysts on the aircraft. This data transfer would be accomplished through satellites and a variety of data links.

Wes Colburn, Lockheed Martin's deputy vice president for ISR systems, envisions the ACS as an independent, "robust" system that does not have to be reconfigured for each mission, and can rapidly deploy ahead of ground forces and operate with minimal or no outside support.

Northrop Grumman is leveraging its experience with the Guardrail and Airborne Reconnaissance-Low programs, as well as the E-2C and E-3 radar warning aircraft, the E-8 Joint Strategic Attack Radar System and the company's Global Hawk unmanned reconnaissance plane. The company's proposed ACS mission suite includes, for example, the I-band electronic sensor installed in the Global Hawk.