The hangar end wall, with two sliding leaves on a head rail that part to open the full 12 metre arch. Each leaf is its own node with a signed travel along the rail. Dimensions 19.40 x 6.40 x 0.66 m (X x Y x Z). Origin on the wall centre at floor level, which is the port plane, so it sits exactly on a bay end port; metres, +Y up, nose toward +Z, wing span and wheel axles along X. Named pivots: hangar-door-right at (2.22, 0, -0.17); hangar-door-left at (-2.22, 0, -0.17). Connectors: bay hangar at (0, 0, 0) facing +Z. Rigid node-transform clips open, close drive named nodes on their own pivots. No skinning and no skeleton, so the retraction linkage, rotor flapping and lead-lag, propeller pitch change, the swashplate and wing flex are all deliberately static. Sixteen material palette of airframe white, deep blue, warm red, airfield yellow, bare aluminium, steel grey, charcoal, near black tarmac, light grey concrete, olive and tinted glazing, plus five emissive lighting materials for navigation, strobe, taxiway, threshold and interior lights. Flat colours, no texture maps. Original generic design with no manufacturer, type designation, livery, registration or operator marking. Free 3D model for Unity, Godot, Unreal, three.js and Blender. No collision or navigation data.