Based on the above specified requirements the

Fig. 2. Stereo-microscopic views: (a) fractured IGV and (b) non damaged IGV.Figure optionsDownload full-size imageDownload as PowerPoint slide
From the above investigation of the compressor casing no evidence of seizure, corrosion attack, or fatigue crack SB1317 was observed. The historical operation logs from the failed GTG were examined and did not record high IGV’s actuator forcing alarms or shutdown.
4.2. Visual and stereoscopic examination of the rotor assembly
The overall status of the compressor rotor assembly revealed a relatively clean condition. The first and third blades of the stage 1 have been fractured at the airfoil roots, remaining blades present a severe impact damage. The forward tab on the retainer clip for blade 1 was undamaged while the retainer clips for all the other 1st stage blades displayed severely distorted forward tabs (Fig. 3).
Fig. 3. Failed 1st stage compressor blade 1 (large red arrow) and 3 (small red arrow). Undamaged retainer clip for blade 1 (black arrow), Retainer clips for all the other 1st stage severely distorted (white arrows). (For interpretation of the references to colour in dinosaurs figure legend, the reader is referred to the web version of this article.)Figure optionsDownload full-size imageDownload as PowerPoint slide