After failed attempts to replace the president's fleet of transportation helicopters in the past decade, the U.S. Navy has rebooted the acquisition project and expects to have new aircraft aloft by 2020.

Sikorsky Aircraft Corp., who has supplied the helicopters that act as Marine One for the president for more than 50 years, has teamed up with Lockheed Martin Corp. for the project.

"We look forward to competing to build and support the next Presidential helicopter fleet," said Frans Jurgens, a Sikorsky spokesman, who said the company will offer its S-92 aircraft for the replacement model.

Late last week, the Navy issued a draft request for proposals, taking a new tack on aircraft acquisition by preferring off-the-shelf helicopter models rather than building them from the ground up. A final request for proposals could be issued as early as March 2013 and a contract issued by 2014.

If Sikorsky wins the contract, Jurgens said, most of the work would be done in the company's Coatesville, Pa.-location, with advanced systems and finishing touches being done by Lockheed in New York and Sikorsky in Stratford.

"The current fleet is reaching the end of their useful service life," said Kelly Burdick, a Navy spokeswoman. The current helicopters used by the president, vice president and visiting heads of state are Sikorsky helicopters, eight of which went into service in 1989 and the other 11 in 1979.

The fleet is operated by the Marines, though the Navy handles the acquisition process.

Over their lifetime, the fleet has been maintained and overhauled through replacement parts. Eventually, though, the service and maintenance of existing helicopters reaches a point of diminishing returns. "There becomes a point when it costs the taxpayer more to operate the older helicopters" than to replace them, Burdick said.

The draft proposal released last week set its "affordability profile" for the program costs at $1.4 billion to be spent from 2014-2020.

It's common for companies to team for projects like these so that one will handle the main helicopter build, with the other integrating specialized systems like radar and communications systems.

Northrop Grumman and Agusta Westland, a Finmeccanica SpA unit, plan to develop a version of Augusta Westland's AW-101 for the presidential replacement. Boeing said that it will determine whether its H-47 Chinook or V-22 Osprey will fit the project's specifications.

Though relatively small in contract size compared to normal defense projects, the contract to build the U.S. president's helicopter carries weight in other areas. "It's the biggest little acquisition," said Bettina Chavanne, a Lockheed spokeswoman. "But what it means for the country and companies involved is much more."

The companies plan to participate in a conference during the week of Dec. 10, where a U.S. Navy official will answer questions about the project.

Sikorsky lost the presidential helicopter program to Lockheed in 2005. But the program went grossly over-budget — growing from an expected $6.5 billion in 2005 to $13.0 billion by the end of 2008 — and was cancelled in 2010 at the request of President Obama and then-Defense Secretary Robert Gates.

The U.S. Department of Defense spent $3 billion by the time the program was cancelled, and, unused by the United States, the helicopters, equipment and parts were sold to Canada and Denmark. The federal Government Accountability Office wrote numerous reports on the program, concluding that it lacked both planning and flexibility as the project advanced.

Douglas Royce, an aerospace analyst with Forecast International in Newtown, said that the shift of preference to existing model aircraft is, in part, thanks to the losses from the Lockheed contract.

"After spending close to $3 billion with nothing to show for it, it would be understandable if the Navy is more risk averse now than they were the first time around," Royce said.

Buying a company's existing helicopter model and modifying it to suit particular needs still has risks, Royce said. But "the less new tech is used in the aircraft, the more likely the aircraft will be delivered on time and on budget."