Lockheed Martin has activated several trade studies to support a US Navy version of the Aerial Common Sensor (ACS) aircraft, despite continuing paperwork delays dragging out the service's official commitment to the project.

A notable configuration change for the navy version could involve installing an in-flight refuelling probe on the Embraer ERJ-145 airframe. Jerry Lindfelt, deputy vice-president for Lockheed Martin Integrated Systems and Solutions, says the USN requirement may seek a longer-range capability than the US Army version, which could be enabled by the addition of a refuelling probe.

Embraer has already drafted design concepts for an in-flight refuelling probe for the ERJ-145, and those are being explored to address the potential USN need, says Lindfelt. The army launched the ACS development programme last August by awarding an $879 million contract to the Lockheed team. The navy is planning to join the programme with an order for 19 aircraft, but has been delayed by an unexpectedly long process to clear the plan through the Defense Acquistion Board. Lindfelt says the approval process has been slowed simply through administrative inertia, but the delays continue to spark questions about the extent of the USN's support. Joining the army's ACS programme was not the USN's first choice for replacing an ageing Lockheed EP-3 Aries fleet. That role was originally assigned to the Multi-mission Maritime Aircraft (MMA) programme, which is now designated the Boeing P-8A.

But a departmental directive to assign joint roles for at least one of the three surveillance aircraft programmes – ACS, MMA and the US Air Force's Multi-Sensor Command and Control Aircraft (MC2A) – led the USN to join the army programme. The addition of the in-flight refuelling probe, which is still deemed as merely an option, could soften the USN's transition from the EP-3 to the smaller ACS design. The ERJ-145 cabin provides room for six workstations, or about 13 fewer than found aboard the EP-3.

STEPHEN TRIMBLE/DENVER

Source: Flight International