1.1 This International Standard specifies the geometry and the partial dimensions of rails and studs used for securing passenger equipment and for cargo restraint, necessary to ensure interchangeability of these items.
1.2 Individual strength requirements will determine the complete rail shape, such as incorporating the standard section integrally into an I-beam extrusion.
1.3 The overall shape of the studs above the top of the rail will depend upon the application. The upper portion may be cylindrical to fit into the tubular structure of a seat or galley unit. Alternatively, it may have a ring attached to serve as a tiedown point for a rope or strap.
1.4 The rail imparts loads in the upward, downward, sideward, forward and aft directions. Forward and aft loads are applied to the track by means of a “shear plug??, a part of the pin assembly (or structure to which the stud is joined) which engages in the rail notches [20,8 mm (0.800 in) in diameter], but this is not included in this International Standard.
In the case of seat attachment or similar application, the downward load is applied to the upper face of the rail by a fitting which is also part of the seat, but this is not included in this International Standard.