Airbus intends to pressure-test the assembly line for the A320neo with several preliminary airframes to ensure it can support production ramp-up demand.
Customers have ordered 1,425 A320neos - a total which does not include the American Airlines deal for 130 - and the airframer is keen to capitalise on a two-year window before the rival Boeing 737 Max arrives.
The pre-series aircraft, built after the eight test airframes, will enable Airbus to examine any possible weak points in the component supply chain and assembly line.
"We're aware how sensitive this product is," says A320neo senior vice-president Klaus Roewe, estimating a need for a "single-digit" number of pre-series airframes - but a higher level of components - depending on what the manufacturer needs to prove.
"We will really stress-test the industrial system to make sure [it can handle the strain] when the ramp-up is coming."
A320neo production will begin in the fourth quarter of 2015 with a "reasonable amount" of aircraft, adds Roewe.
Airbus, which is taking A320 production to 42 per month this year, intends to maintain this rate during the transition to the re-engined variant. "We do not foresee a drop [in the overall rate]," says Roewe. However, he adds that the airframer needs an initial low production run to check integrity.
"If there's any difficulty we'll get to know them far in advance before production starts," he says, adding that production of the A320neo will initially start on European final assembly lines.
Airbus will retire its MSN1 A320 test aircraft once the first Pratt & Whitney-powered A320neo flies. In the meantime, Germany's DLR aerospace agency is assisting with development testing with its A320 testbed, MSN659, in addition to MSN1.