Airbus has identified its first potential customer for the A319neo after Frontier Airlines's parent, Republic Airways Holdings, tentatively signed to take 40 of the type in a deal that would also include 40 A320neos.
While the deal is still in the form of a memorandum of understanding, it raises questions about Republic's agreement for 40 Bombardier CSeries jets that were timed to arrive at Frontier as older A319s were being withdrawn.
All the A320neo-family aircraft would be powered by CFM International's Leap engine, rather than the Pratt & Whitney geared turbofan - the engine that would be fitted on the CSeries.
Republic's agreement is the first to identify the A319neo variant specifically since the re-engined A320 family was launched.
Latin America's Avianca-TACA also bolstered the potential A320neo backlog with a memorandum of understanding for 33, part of a broader deal for 51 A320 jets.
Airbus, which had indicated in April that it was expecting a Latin American deal for the A320neo, said the agreement would amount to the largest order for the type in the region once firmed. Avianca-TACA has not made an engine selection.
India's IndiGo firmed its agreement for 150 A320neos, part of a deal which also includes 30 firm A320s. The airline previously selected the PW1100G engine for the batch of re-engined twinjets.
Kuwaiti lessor ALAFCO added another six A350-900s to its previous firm order, taking its backlog for the Rolls-Royce Trent XWB-powered type to 18.
Rival Boeing did not unveil any similar surge of orders but secured a deal with Russian operator UTAir to provide 33 737-800s and seven 737-900ER aircraft. The aircraft come with CFM International CFM56 powerplants as standard.