If possible, restart
If the engine has failed or flamed out, and there is no indication of engine damage, it is always possible to attempt to restart the engine.
Engine damage can be suspected if some of the following symptoms are observed: • Rapid increase of EGT above the red line • Important mismatch of rotor speeds (N1 vs N2 or N3) or absence of rotation.
• Abnormal oil pressure/temperature
• Loud noise • Fumes or burning smell in the cabin. If a visual check is possible, the crew should look for damage to the engine cowling or aircraft structure, or missing engine parts.
Reproduced from:
Flight Operations Briefing Notes. Supplementary Techniques.
Handling Engine Malfunctions.