The US Air Force's KC-X tanker contest is likely to remain a face-off between the Boeing KC-767 NewGen Tanker and EADS North America KC-45, with surprise late bidder US Aerospace acknowledging that it faces long odds to secure a deal.
The air force's evaluation team may decide that Antonov is an "unacceptable" subcontractor for a KC-X bid, says California-based US Aerospace, which signed a security co-operation pact with the Ukrainian company on 1 July.
Submitted eight days later, its offer carried a price tag of $29.5 billion, undercutting the estimated $35-40 billion previously described for the 179-aircraft deal.
But in a new regulatory filing to the US Securities and Exchange Commission, US Aerospace says other possible shortcomings include an inability to handle classified information and a failure to have entered into "required teaming agreements" before the 9 July deadline.
USAF officials are expected to award the KC-X contract in mid-November.