The US Army is considering shifting to turboprop aircraft for its next-generation aerial common sensor (ACS) fleet, potentially reversing a key focus of its acquisition strategy after a star-crossed, six-year pursuit of jets, according to industry sources.
The potential change has been disclosed during the last three weeks in private notices and informal discussions to several potential ACS suppliers, according to multiple industry sources.
Specifically, the army in late April issued a request for information seeking basic knowledge about how turboprop aircraft could support a changed vision for the ACS mission, with potential payload sizes ranging from 2,265kg (5,000lb) to 9,075kg.
On 15 May, Alenia confirmed it responded to the army's notice by proposing two aircraft: the ATR 42 and the C-27. The army has already ordered the latter, although its C-27Js are proposed to be transferred to the US Air Force next year. A special mission variant of the ATR 42, meanwhile, is also in service as a maritime patrol aircraft with the Italian coast guard and customs and border patrol agencies.
Kevin Hopkins, Raytheon's lead executive for the ACS competition, says that military variants of the Beechcraft King Air 350, the Bombardier Q400 Dash 8 and EADS Casa turboprops also could qualify for the same role.
As a systems integrator, Raytheon believes the potential switch to turboprop aircraft would significantly improve its competitive chances.
"Turboprop-based [intelligence, surveillance and reconnaissance] is known very well to us," Hopkins says. "We look at ourselves as very viable in that market space. We are very supportive of this direction that the programme manager is going in."
Such a shift would shake up the teams of bidders that have been pursuing the contract for most of the last decade. Until recently, the army had decided to pursue a business jet-sized platform, with the Gulfstream G550 and Bombardier Global Express XRS as the leading contenders.
Last year, systems integrators formed their teams, with Northrop Grumman partnering L-3 Communications and Boeing signing a non-exclusive agreement with Gulfstream. Northrop confirms it remains interested in the ACS competition.
Boeing EPX manager Paul Summers says the army has already decided to shift to turboprops, adding that the change would finally separate the ACS requirement from the US Navy's need to replace the EP-3 Aries II with a jet-powered EPX.
However, Raytheon's Hopkins says the army's plans have not been finalised.
"We're not really sure what's going to happen," Hopkins says. "There's been an indication of what they're thinking about, but there has been nothing official."
The army's ACS programme office did not immediately reply to requests for comment.
The ACS contract was originally awarded in 2004 to a Lockheed Martin/Embraer team, but the deal was cancelled in January 2006 after the sensor payload outgrew the capacity of the ERJ-145 regional jet.
A few years earlier, Lockheed had publicly marketed the C-27J platform with its then-partner, Alenia, for ACS, suggesting that the Italian-made spin-off of C-130J propulsion and avionics technology would enter the US inventory as a signals intelligence aircraft.