What is the maximum permissible gross weight of the test aircraft during takeoff and landing specified in?

The maximum permissible gross weight of an aircraft during takeoff and landing is typically specified in the Pilot's Operating Handbook (POH). The POH contains critical information about the aircraft, including performance data, operating limitations, and various weight and balance specifications. This document is essential for pilots to refer to before flight, ensuring they adhere to safety regulations and aircraft limitations.

The weight limits outlined in the POH are crucial because exceeding them can significantly affect the aircraft's performance, stability, and control, especially during critical phases of flight like takeoff and landing. This document serves as an authoritative source for the pilot to ensure safe and legal operation of the aircraft under various conditions.

While the other documents mentioned may contain relevant information regarding the aircraft or operations, the POH is the primary source specifically detailing the operational limitations, including gross weight for takeoff and landing.