Porosity and misalignment — frame F-310

Defect found during first-article inspection of Frame F-310. The J-groove weld showed misalignment with porosity along the root; joint gap measured at 1.7 mm against a 1.5 mm maximum.

Root cause: the two-point locating scheme allowed the upper flange to rotate under clamping load, opening the gap on the far side of the groove.

Corrective action: Fixture redesign; wire lot quarantined.

Disposition: rework and re-inspect. Lesson recorded for drawings using the same locating pattern.