Which vertical flight path mode reduces airframe structural loading during rough weather?

The vertical flight path mode that reduces airframe structural loading during rough weather is turbulence mode. This mode is specifically designed to automatically adjust the aircraft's altitude to counteract the effects of turbulence. By continuously monitoring and adapting to changes in vertical speed, the turbulence mode can help minimize sudden and severe movements that would otherwise impose additional stress on the airframe. This helps in enhancing passenger comfort and ensuring the structural integrity of the aircraft.

In contrast, vertical speed, altitude hold, and altitude select modes do not inherently focus on mitigating the effects of rough weather in the same manner. Vertical speed mode allows for the pilot to control the ascent or descent at a constant rate, but does not react dynamically to turbulence. Altitude hold maintains the aircraft's current altitude without compensating for vertical motion due to turbulence. Altitude select allows the pilot to set a desired altitude, but again, it does not provide adjustments for abrupt weather changes. Hence, turbulence mode stands out as the optimal choice for managing structural loads during challenging weather conditions.