The seatback tray table

The tray table drops in a single practiced motion when its clip is thumbed open, catching itself just before full extension on a hinge that has done this several thousand times without much ceremony. The latch gives one soft click, definitive sounding, and yet the table wobbles regardless: a rock along its long axis, sometimes half an inch, sometimes barely perceptible, present on tables that are three years old and tables that are three months old alike, suggesting the wobble is not wear but design, an inherent slack built into the hinge to keep it from binding. Passengers respond to the wobble by bracing a hand at the corner while writing, or by abandoning writing altogether in favor of the tray's more reliable function as a shelf for a cup, a phone, a half eaten pretzel bag folded shut. Folded back up, the table disappears almost completely into the seatback, a feat of packaging that belies the wobble it produces when deployed, and the folding motion itself, tray meeting seatback with a soft double thud, has become one of the more recognizable sounds of a flight beginning its descent, right alongside the chime and the flight attendant's instructions. Some models fold from the armrest instead, a design decision that solves nothing and simply relocates the wobble to a different joint.

R. Quist