The following all affect the airworthiness of your paraglider, and should be checked as follows:
The recommended inspection frequency is specified in the paraglider owner's manual.
Line lengths are crucial since they control the shape of the wing.
The "check length" of the lines is defined as the distance from the lower surface of the canopy to the inside edge of the maillons connecting the lines to the risers. It must be measured with 5kg line tension.
The measured lengths of individual lines should match those in the line-lengths table within a +/-10mm tolerance. The tables are specified in each glider manual. An offset of +/-50mm of the line-lengths table is acceptable. That is to say, the entire line set can be longer or shorter up to a maximum value of 50mm.
The risers should be measured as part of the overall line length. The measurements of each riser's branch under 5kg load should match the lengths specified in the manual with a tolerance of +/-5mm.
The line breaking strength should be measured by slowly increasing the tension of a single dismounted line until it breaks.
The minimum acceptable value is defined as follows:
The same calculation applies for mid and upper levels. Minimum value for upper lines is 30kg.
The tear strength is measured with a calibrated Bettsometer. The measurement should be made at the middle of a panel near the centre of the upper surface. At 600g load, the tear should not exceed 5mm, or break a ripstop thread.
Porosity is measured with a calibrated Porosimeter. It should be measured in at least 3 different places on the upper surface, at 20-30cm from the leading edge in the centre of a panel.
Minimum acceptable value is 10 seconds. Below, the glider must be flight tested for approval.
The different components of the wing should be visually checked: panels, ribs, structural diagonals and straps, plastic rod sleeves, tabs, lines, splices, risers, seams…
Any damaged part should be repaired or replaced according to the manufacturer's specifications and reported in the maintenance logbook.