🔍 Key Concepts

• Trace the labeled cooling-air flow lines in the GT-0020 diagram specifically around the HP turbine 2nd stage nozzle vanes area. • Notice which compressor bleed (9th, 13th, or 16th stage) is routed toward the high‑temperature turbine section versus being sent to customer bleed or frame vent. • Distinguish between air used for frame venting / sump pressurization and air used for nozzle and blade cooling.

💭 Think About

• Starting at the HP turbine 2nd stage nozzle region, which color‑coded line and label feed directly into that part of the turbine? • Compare where the 9th, 13th, and 16th stage bleed lines terminate— which one actually enters the turbine nozzle area rather than leaving the engine as customer bleed or going to frame vents? • Is any of the air first used for another purpose (such as thrust balance or customer bleed) before it reaches the 2nd stage nozzles, or does one bleed supply them directly?

✅ Before You Answer

• Verify the exact label printed next to the line that enters the 2nd stage nozzle vane region—match that wording to one of the answer choices. • Confirm that the line you are following does not end at a label such as Frame Vent or Customer Bleed, which would rule out that option. • Double‑check that you are looking at the HP turbine 2nd stage, not the 1st stage or LP turbine, to avoid mixing up cooling sources.