Borescope
A device that enables the inspector to see inside areas that could not otherwise be inspected without disassembly.
Also defined in 1 more source
An inspection tool for viewing the inside of a turbine engine without disassembling it. The instrument consists of a light, mirror, and magnifying lens mounted inside a small-diameter tube that is inserted into a turbine engine through borescope inspection ports.
Aviation Maintenance Technician Handbook — Powerplant, p. G-4
Taught in GEN-K Procedures, PP-B Procedures, PP-B Quick reference, PP-L Procedures.