Boeing is on track to release design drawings to the supply chain for the 787-10 later this year, with a goal of achieving commonality with the 787-9, a top executive at the airframer confirms.
The double-stretch of the 787-10 will share the maximum take-off weight of the -9 despite a 5.5m (nearly 14ft) increase in fuselage length to accommodate 43 extra passengers in standard configuration.
Sharing the same certification weight opened an opportunity to maximise production efficiency, but only if Boeing could overcome several complications.
One problem involved inventing a way to preserve the size of the 787-9 horizontal stabilisers despite the increased length of the -10.
"Even though the weight is the same, the distribution of forces can be different," says Scott Fancher, general manager of airplane development.
The 777-9X, for example, represents an even larger fuselage stretch and requires a new pair of stabilisers longer by about 127cm.
However, Boeing engineer Vedad Mahmulyin discovered a way to use software to balance the aerodynamic forces for the 787-10 using the same stabilisers as the 787-9.
"This one was a great example of where an engineer was able to think of a different way to achieving commonality and develop a simple solution for enabling that," Fancher says.
Boeing named Mahmulyin as the company's "engineer of the year" for discovering the solution.
The overall software lines of code remains "highly common" between the -9 and -10, he says.
"You may see subtle differences in the gains between control laws, for example, to account for the fact that the loads are distributed differently even though the gross loads are the same," Fancher says.
Other known structural differences between the two aircraft are limited to a semi-levered landing gear and a tail skid on the -10.
Source: Cirium Dashboard
