Equipment expertise and technical control in paragliding are the foundations of pilot safety. An instructor is not just a "user"; they must be a technical diagnostician capable of reading the "health" of the equipment before a defect ever manifests in the air.
Here is an in-depth overview of these critical areas in English:
1. Wing Fabric Expertise: Porosimeter and Bettsometer
Wing fabric loses its structural properties over time due to ultraviolet (UV) radiation, humidity, and mechanical friction.
Porosity Test: This is the most accurate method for determining fabric wear. A specialized device called a porosimeter measures the time it takes for a specific volume of air to pass through the fabric.
Why it matters: If the fabric becomes too permeable, the wing loses internal pressure. Such a wing is prone to Deep Stall (parachutage), becomes difficult to launch, and its handling becomes dangerous.
The Instructor's Role: They must know how to conduct tests at various points on the wing, especially the Leading Edge, where internal pressure and wear are highest.
Bettsometer Test: This device checks the mechanical tear strength of the fabric. A specialized needle applies a specific load (e.g., 600–1000 grams) to the fabric.
If the needle punctures the fabric or snaps a thread, the wing is considered unairworthy and its operation must cease immediately.
2. Line Geometry and Trim Check
Paraglider lines are not static; they behave like a living organism that is constantly changing.
Shrinkage and Stretching: Rear lines (C and D rows) carry less load and often shrink, while front lines (A and B rows) tend to stretch. This causes an increase in the wing's Angle of Attack.
The Risks: A wing with incorrect geometry becomes "slow," struggles to recover from negative flight regimes, and has a significantly higher risk of stalling.
Trim Check: An instructor must be able to use a laser rangefinder to measure line lengths and compare them to the manufacturer's technical specifications. Even a small deviation (10–15 mm) requires correction (trimming).
3. Reserve Parachute Installation Control
Many incidents occur not because the parachute failed to open, but because the pilot was unable to extract it.
Closure Pins: Before every flight, the instructor must check that the pins are not inserted too deeply or corroded.
Compatibility: They must verify that the parachute volume is appropriate for the specific harness container.
Repack Interval: The instructor is responsible for ensuring the student's reserve has been repacked within the last 6–12 months.
4. Certification Mastery (Equipment Suitability)
This acts as both an ethical and technical filter.
EN Classification: An instructor must thoroughly understand the differences between EN-A (school) and EN-C/D (sport/competition) wings.
Responsibility: It is unacceptable to place a student on a high-class wing, even if the student is "talented." In critical situations, high-class wings require reactions that a student does not yet have in their muscle memory.
Weight Range: The instructor must verify that the student's Total Take-Off Weight (TTOW) falls within the certified weight range of the wing.
Summary
Technical expertise is what defines a professional instructor. When you hold a porosimeter or verify line geometry, you are managing risks that are invisible to the naked eye. This is "invisible safety" that preserves human life.