For an aerotow of a glider with a certificated gross weight of 700 pounds, what is the minimum allowable towline strength?

• A. 400 pounds
• B. 560 pounds
• C. 700 pounds
• D. 840 pounds

Answer: (B)

The key idea is that towline strength must provide a safe margin over the glider’s weight to handle the peak loads during aerotow launch. For a glider with a maximum gross weight of 700 pounds, the minimum required towline strength is 0.8 times that weight, which is 560 pounds. This ensures the line can handle dynamic tension without failing, while not being needlessly strong. The other options are either too weak (400 pounds) or exceed the minimum (700 or 840 pounds), so 560 pounds is the correct minimum.