Engineering Brief 105 is the document that turned urban air mobility from a render into a dimensioned drawing. It specifies the deck: a 12-inch solid white line around the touchdown area, a 12-inch dashed line around the final approach area, a broken-wheel identification symbol, a black-on-white weight-limitation box.

This system builds an interface out of those figures. Grey concrete is the page. White paint is the structure. Aviation green — the chromaticity mandated for every perimeter light — is the only saturated colour, and orange belongs to the wind cone. Nothing here is decoration; every mark is a line with a specified width.