Weight on Wheels: XB-1 holds its own

Weight on Wheels. For the XB-1 team, the moment for weight on wheels came on a recent Saturday in the hangar. After close to a year of housing the aircraft in a “cradle” structure, the team released XB-1’s supports and gradually lowered its full weight onto the wheels. Slowly, XB-1’s landing gear took more and more of the load until the team removed each of the supportive jack points and it stood on its own for the first time.

Balance. In the words of shop techs, no aircraft should ever pop a wheelie. At the same moment that the landing gear took the full load, XB-1 maintained balance. By correctly identifying the aircraft’s center of gravity beforehand, and balancing weight, the team mitigated any risk during the milestone.

Manufacturing Engineer Casey Fischer shared that weight and balance were not the only potential issues the team anticipated: “We continually examined XB-1’s jack points as we released weight onto the landing gear. During this operation, the jack points can slip if not lowered evenly or consistently. This could put loads where they don’t belong, causing damage to the airframe. By progressively adding weight to the landing gear, and doing it slowly, we preemptively minimized the issue and didn’t experience any problems with the jack points.”

Ride Height. The team also scrutinized XB-1’s ride height (or height off the ground) to guarantee that it’s exactly as anticipated during the design phase — and it was.

“Our teams built the landing gear in-house, so this was a professional milestone for all involved,” continued Fischer. “Thanks to extensive testing beforehand, we had a very good confidence level going in and that continued through the final minutes.”

Multi-team milestone. Achieving a successful weight on wheels milestone drew on the expertise of several teams, including manufacturing, structures, landing gear and flight testing. It was the culmination of a year’s work.

The teams shared in the excitement of weight on wheels by putting XB-1 onto “skates,” which allow the team to easily move it in any direction around the hangar, rather than only forward and backward. As Fischer remarked, “It was the fastest and farthest XB-1 has traveled to date — a huge day for the team and a major milestone in the build.”