Why this answer
The verdict comes from all three measured axes.
Tumi Voyageur Celina Backpack is over the published personal-item dimensions, but the soft construction may make it a borderline option if lightly packed. Treat this as a fee-risk result.
The selected rule is 17 x 10 x 9 in and the bag record is 15.9 x 10.6 x 6.5 in.