Aero-engine compressor blade and disc assemblies are subjected to high thermo-mechanical loads due to high-speed rotation and gas loads. Compressors are one of the critical components in the engine as their catastrophic failure could cause the engine casing to fracture completely This could result in the destruction of the engine and in loss of human life. Hence, failure analysis of these critical components is of great importance. In this study, static analysis is done initially to find the critical crack orientation at the root of the blade. With simulated initial cracks, the cracks are allowed to grow in low cycle fatigue (LCF) and isochromatics are captured at selected intervals. Using digital photoelasticity, isochromatic images are used along with an over-deterministic least-squares approach to find the fracture parameters. As the stress fields are very complex, a multi-parameter solution with a higher number of parameters were needed to model the stress field. Crack growth angles are evaluated using MTS, SED and GMTS criteria. It is observed that the GMTS criterion predicted closer results to that of experimental values, which implied the significance of T-stress in predicting the crack growth angle.