🔍 Key Concepts

• Location of the compressor rear frame in the engine flow path relative to the compressor, combustor, and turbine • What a borescope can see along the gas path when inserted through ports at the compressor rear frame • Which components are located upstream vs. downstream of the compressor rear frame ports in Illustration GT-0006

💭 Think About

• Trace the gas path on the drawing from the 14th stage compressor through the combustor to the 1st stage turbine nozzle and note where the compressor rear frame ports (13A–13F) are located • For each answer choice, ask yourself: would inserting a borescope at the compressor rear frame give a clear line-of-sight to that component without other major structures blocking the view? • Compare what is labeled around the compressor rear frame circle (13A–13F) to the typical inspection views shown for the turbine mid frame and the compression stages

✅ Before You Answer

• Verify exactly where ports 13A–13F are on the main engine drawing and what section of the engine they open into • Check which of the listed components lies furthest away or is shielded by other hardware from the compressor rear frame position • Confirm which components are normally inspected from other borescope port groups (turbine mid frame ports 10A–10R or typical compression stage ports 14–29), rather than from the compressor rear frame