Armavia and Sukhoi are locked in a dispute over the delivery of Superjet 100s after the Armenian flag-carrier stopped operating its first aircraft, having already postponed acceptance of a second.
While the airline is indicating that the technical performance of the twinjet lies at the centre of the tussle, the airframer suggests the real problem is financial arrangements.
Sukhoi's civil aircraft division says that it "hasn't had" any formal notification that Armavia - the first operator to take the type, in April last year - wants to "reject the aircraft and stop the contract".
But the airframer insists that there is a debt attached to the first jet which complicates the matter. "Even if [Armavia] rejects the contract, it can't give back the [aircraft]," it adds
The airframer says the carrier acquired its first aircraft directly but the second has not been delivered, and claims that part of the hold-up is due to the carrier's trying to rearrange the financing to place both Superjets under a lease agreement.
Both Armavia aircraft, fully painted in the airline's livery, are parked at Moscow's Zhukovsky airfield while talks are taking place over their future.
Armavia explains the situation, however, as being related to the operational performance of the Superjet, claiming it has not met the Yerevan-based carrier's expectations.
"Although it's a brand new aircraft it needed to be repaired within the first year after entering service," says the operator.
"This raises a question about the advisability of that purchase. We're a small carrier and cannot afford to make experiments."
Armavia had previously been broadly upbeat about the type, indicating that the aircraft met its network requirements, but had hinted at a need to refine its operations.
Earlier this year Russian authorities briefly suspended Armavia's route rights over unpaid air traffic control debts.