The six borescope ports located in the compressor rear frame casing of the marine propulsion gas turbine shown, can be used to inspect all EXCEPT which of the following components? Illustration GT-0006

Correct Answer: Option A — 14th stage compressor blades.

Borescope ports in the compressor rear frame are positioned to view the combustor and turbine sections. The 14th stage compressor blades are located too far forward in the compressor section to be inspected through these specific rear-frame ports, which are designed for high-pressure turbine and combustor access.