PLT496: Towrope Strength And Safety Links
What code PLT496 covers, why the FAA tests it, and how to study Towrope Strength And Safety Links before your checkride.
Recall towrope - strength / safety links / positioning
What this means for your checkride
Tow line strength must fall within 80 to 200 percent of the maximum certificated operating weight of the glider. A stronger line may be used only if two safety, or weak, links are installed. The link near the glider must meet the same 80 to 200 percent range, and the link near the towplane must be stronger, but not more than 25 percent greater than the glider-end link and not more than twice the glider's maximum certificated operating weight. Tow ropes are inspected before every flight because a knot in the line can reduce its strength by up to 50 percent and create a high-wear spot.
Weak link and tow line strength limits are regulatory requirements that appear directly on the knowledge test.
The two weak links are not identical. The towplane-end link is intentionally slightly stronger so that under excess tension the glider-end link fails first.
Where to study it
A code on your test report is an area of deficiency. An authorized instructor must review it with you and endorse that review before you take the practical test, and the examiner may revisit it during the oral. Study it until you can explain it out loud, not just recognize the answer.