The proposed Phase 1 program will fabricate and demonstrate a small diameter single fiber endoscope that can perform high temperature thermal imaging in a jet engine turbine and combustor. Task work will design, fabricate, calibrate, and test the single fiber thermal imaging system in a 1000 C environment. Equipment needs will be documented in detail and system characteristics such as spatial and temporal resolution will be established. Feasibility will be established by demonstrating that a good thermal image of an illuminated high temperature target can be obtained. Imaging access to turbomachinery and combustors in during normal operation or even simple installation in a test rig would be an important advance in aircraft engine diagnosis. A prototype endoscope will be designed, fabricated, and tested in Phase 2.