* Boeing may launch latest version of workhorse jet in June
* Engineers test two-part solution for crucial gear design
* Boeing says no decision taken, discussion of timing premature (Adds details, background)
By Tim Hepher
PARIS, April 25 (Reuters) - Boeing is nearing a decision to launch a larger version of its 737 workhorse jet within two months to counter strong sales of the Airbus A321neo, after a breakthrough on the design for one of its parts, industry sources said.
The 737 MAX 10 would narrow the gap between the 178-220 seat 737-9, which first flew this month, and the 185-240 seat A321neo, which dominates the top end of the market for narrowbody jets.
Boeing has been studying how to solve a tricky problem with the design of the plane’s landing gear, without adding cost or delaying a 2020 target for first deliveries.
The sources said a two-part technical solution is being tested and that Boeing is negotiating with airlines with the aim of launching the 737-10 at the Paris Airshow in June.
“Boeing is actively engaged in discussions with customers about the 737 MAX 10X,” a spokesman said.
“No decision has been made on the airplane and any discussion on timing of a possible launch would be speculative.”
Reuters reported last year that the 737-10 marks a quick tactical response to the A321neo, while Boeing works on pivotal plans for a 220-260-seat twin-aisle, mid-market jet.
But it has produced a puzzle so tricky that Boeing has asked for help from its combat jet experts to design a space-saving gear for the 737-10.
A solution is needed because the 737-10 will be longer than the 737-9 to make room for about 12 extra seats. The landing gear must become taller too or the tail could scrape the runway.
Anxious to avoid costly changes to the rest of the plane and stay on schedule, Boeing aims to make the gear longer only when needed, but small enough to fit in the 737’s existing wheel bay.
It has not made final decisions but is testing an advanced proposal to allow the 737 to effectively sit back on its heels as it leaves the runway.
This is what aerospace engineers call a “semi-levered” design and is a nod to two bigger jets: the 777 and 787-10.
In a further twist, the gear would lengthen telescopically for the 737-10 to charge down the runway. Afterwards, it would shrink again to retract into the same space.
Boeing is said to anticipate a market of 1,000 of the planes. (Editing by Sudip Kar-Gupta and Jason Neely)