Airbus's maximum take-off weight increase for the A220 is effectively a paperwork change, rather than a structural adaptation.
The MTOW hike of nearly 2.3t is due to become available from 2020, and Delta Air Lines has emerged as a customer for the upgrade.
"The level of modification is very limited," A220 programme chief Florent Massou tells FlightGlobal, mainly a matter of small reinforcements, combined with "paperwork and software".
This means the "marginal" changes can be retrofitted, he adds.
Massou indicates that Bombardier's original specification for the aircraft was probably a little conservative, and that Airbus is keen to exploit the type's full potential.
"We were answering a market request," he says. "We knew the platform was capable of doing that.
"We see it as a very dynamic programme with lots of potential."
Delta Air Lines increased its A220 order to 95 aircraft during the Paris air show, by adding a further five A220-100s, and disclosed that it would take the higher-weight version.
The MTOW increase extends the range of both variants by 450nm.
Delta's agreement was one of several deals for the A220 during the show comprising 85 firm and committed aircraft.
Aside from Delta's five, these agreements included 50 for Air Lease, 20 for Nordic Aviation Capital, and 10 for an unidentified customer – which is another airline, not a lessor, says Airbus.
Airbus is aiming to deliver 45 aircraft this year, up from last year's 33. It had achieved 15 deliveries by the end of May.
The airframer has completed the transfer of procurement, supply-chain arrangements, and sales and marketing integration following its acquisition of the former Bombardier CSeries programme, and is aiming to finalise, over the next year, the support network.
Airbus is focusing on increasing the despatch reliability, and Massou says the figure is "close to" 99%, following upgrades to installations such as the cabin-management system which have provided a "tangible improvement".