Where would you find the code letter indicating the moment weight of the turbine blade?

• A. The blade tip
• B. The fir tree section of the blade
• C. The blade root
• D. The blade shank

Answer: (B)

Weight or moment information is attached where the blade seats to the disk—the fir-tree root. This area is the reference point for the rotor’s balance, so the code letter identifying the blade’s moment weight is placed on the root portion that stays with the hub during operation and maintenance. Marking the tip or shank wouldn’t be reliable for balancing—the root is the fixed, critical location that determines how the blade’s mass affects the rotor, and it remains with the blade throughout installation. By stamping the code on the fir-tree root, technicians can correctly match and balance blades during assembly.