Three competitors have submitted bids to the US Air Force to win a $15 billion combat search and rescue (CSAR-X) helicopter contract in the third attempt to successfully settle the deal.

The Boeing HH-47 Chinook (below) won the original competition on 9 November 2006, but the contract was overturned by the US Government Accountability Office.

The two losing teams – Lockheed Martin/AgustaWestland and Sikorsky, respectively offering the US101 and HH-92 – also successfully protested the USAF’s second CSAR-X competition, forcing the service to solicit for a third round of bids.

© Boeing

All three bidders confirmed submitting bids by the 20 January deadline for the USAF’s extended solicitation process. USAF officials will evaluate the proposals and still plan to select a contractor in the second quarter. However, Barack Obama's incoming administration could change the timeline.

Boeing says in a statement to that its “proposal continues to focus on the proven strengths of the HH-47 platform, an active production line and the exceptional performance of the aircraft in combat and in humanitarian operations”.

Lockheed and Sikorsky confirm that they have also submitted updated proposals.

The terms of the new competition were developed over a roughly two-year period. The USAF had hoped to award a contract last month, but acquisition officials detected a potential fall in the wording of the service’s terms for the evaluation criteria. The delay pushed the final decision for the CSAR-X selection to the new administration.