Abstract: Aircraft electrical wiring is exposed to frequent thermal cycling during service, which can induce thermomechanical degradation of the insulation. the insulation of aircraft feeder cables was subjected to thermal cycles between −50 °C and 200 °C (180 total cycles), with specimens sampled every 60 cycles for thermogravimetric analysis (TGA) and Fourier-transform infrared (FTIR) spectroscopy. The isoconversional Kissinger–Akahira–Sunose (KAS) method was used to determine the apparent activation energy (Ea) as a kinetic descriptor of aging-induced changes in pyrolysis. Ea decreased monotonically with cycle count: 296.99 kJ·mol⁻¹ for the unaged sample, falling to 284.23, 262.45, and 253.47 kJ·mol⁻¹ after 60, 120, and 180 cycles, respectively, indicating a lowered energetic barrier for thermal decomposition and diminished thermal stability. Consistently, FTIR spectra show attenuation of –CF₂– bands with aging, consistent with C–F bond scission along backbone and associated chemical degradation. These results demonstrate that thermal cycling under the present conditions significantly compromises the thermal stability of insulation, providing an experimental basis for aging assessment and protective strategies for aircraft wiring.