How many stages is the low pressure turbine?

• A. 2
• B. 4
• C. 6
• D. 8

Answer: (B)

The number of stages in a low pressure turbine is about how many rotor stages are needed to extract enough energy from the hot exhaust to drive the low‑pressure shaft (the fan/low‑pressure compressor). For this engine family, four stages are used in the low pressure turbine. This gives a good balance: enough energy extraction to turn the low‑pressure spool efficiently across operating conditions, without adding unnecessary weight or complexity. Too few stages would leave the shaft underpowered and could limit thrust or performance, while too many stages would add mass and mechanical complexity with little to no benefit. Four stages provide the design’s required energy extraction and operability for the engine.