Slightly longer wings and less-distinctive engines will be two new features of Boeing’s evolving 777X, according to a story this week in Aviation Week and Space Technology.
The wing span has grown to 235.5 feet, by adding one foot to the outboard end of the folding wing tips. The tips will now be 12 feet long, up from the prior 11, which means that when folded up the plane will still be able to fit in the 213-foot “Code E” gates now used by the current 777 300ER models.
Partly because the wings will be slightly longer, Boeing is dividing the wing flaps into three sections rather than two, to prevent any “flutter,” as the wings move through the air.
“To make it stiff enough to avoid flutter risk, it became apparent that we needed to split the outboard flap,” said Terry Beezhold, 777X chief engineer, in the story.
To carry the wings, Boeing has decided to use aluminum for the “center wing box,” which is the section that ties the wings to the fuselage. This will simplify the wing-body join, keeping the center wing box connections similar to those on the current 777.
Another change is that the engines will look more like engines on other aircraft, shedding the distinctive noise-dampening jagged rear edges, called “chevrons,” that are a feature of the 787 Dreamliner. Instead, the company has found a new way to mix air flowing by the nacelles for the 777X, a step that may reduce drag.
Those engines are to be slightly larger in diameter, 133.5 inches, to provide slightly more powerful thrust of 105,000 pounds.