The nuts on the engine mount must be tightened to the torque recommended by?

The nuts on the engine mount must be tightened to the torque recommended by the engine manufacturer because the engine's design and mounting specifications are critical to its safe and efficient operation. Each engine has specific torque values that ensure the engine is securely mounted to the airframe, thus preventing vibrations and misalignment that could lead to mechanical failure.

Following the recommendations from the engine manufacturer ensures compliance with engineering standards that take into account the engine's weight, stress during operation, and the materials used in both the engine and the mounts. This adherence to manufacturer specifications is vital for maintaining airworthiness and ensuring that all components perform as intended under various operational conditions.

In comparison, while the aircraft manufacturer may include information about the engine and its installation, they typically rely on the engine manufacturer for the detailed torque specifications. State regulations may provide general guidelines for safety and maintenance practices but do not usually dictate specific torque values. The assembly technician's recommendations are based on training and experience but should align with the manufacturer's specifications to ensure proper assembly and safety.