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 strategically located to view the combustor and the first stage turbine nozzle. The 14th stage compressor blades are located further forward in the compressor section and cannot be accessed through these specific rear frame ports, requiring different inspection access points.