Boeing chief executive Jim McNerney is favouring the replacement of the 737 with a cleansheet design rather than with an upgraded, re-engined derivative, unless airline demand fails to mature before 2025.
"The number one thing I want to know is...during what timeframe we can get an all-new airplane done that our customers will pay for," McNerney told delegates at the Sanford Bernstein Strategic Decisions Conference on 3 June.
While no final decision has been made on the future of Boeing's narrowbody workhorse and cash cow, McNerney's preference is to move directly to a cleansheet aircraft: "I'd rather not put the backlog at risk twice unless we have to."
McNerney says delivery positions for the 737 are sold out for "several years" beyond 2012.
However, he balances his position and underlines the fact that if customer-driven timing for a new narrowbody offering is pushed until 2025, then "the case for re-engining strengthens. If the answer is 2020, no matter what Airbus does, I think customers will wait for us."
McNerney says studies are looking at "how fast we can flow some technology from the 787 into a new narrowbody".
Boeing's more-electric architecture designed for the 787 is intended to serve as a significant product differentiator and is likely to find its way into the airframer's next cleansheet design.
With scaled-down 787 systems and a future engine offering, Boeing aims to offer between 15-20% direct operating cost savings over today's narrowbody aircraft.
Airbus appears closer to a decision to re-engine its A320 family, remaining resolute in its view that the technologies needed to gain the 30% cost and performance gains required for an all-new single-aisle are at least a decade away. It is planning to decide by year-end whether to re-engine the A320 for a 2015 introduction. Additionally, a 2013 service entry for market newcomer Bombardier's 110- to 149-seat CSeries is weighing heavily on Boeing's decisions to re-engine or replace the 737.
A decision from Boeing on any upgraded narrowbody move is expected by year-end as well. If the airframer opts to re-engine the 737 with powerplants from CFM International and/or Pratt & Whitney, a 2016 entry into service likely to be the target.