C-17 Tow Supervisor and Brake Operator Pre-Test Practice

When towing a C-17, the tow supervisor relies on the tension link scale indicators on the tow bar to measure the actual load being transmitted to each main landing gear. These indicators give a live readout of the force the tow tug is applying through the gear, taking into account vehicle weight, ground resistance, and any steering or braking actions. Keeping that readout at or below the specified maximum protects the MLG structure and tires from overstress during movement, especially on varying surfaces or with dynamic towing conditions.

For this aircraft, the permissible load on each main landing gear during tow is 65,000 pounds. So the supervisor ensures the tension readings stay at or below that value; if the readout nears or exceeds 65,000 pounds, actions are taken to reduce the load, such as adjusting speed or reconfiguring the tow.

The other numbers would either be below the published limit or exceed it, which is why they are not the correct maximum.