The modern airliner is a sophisticated and robust machine, with incredible rates of reliability. This reliability is not lost on the pilots who fly them, and while emergency training generally takes place around four days a year, ubiquitous aircraft reliability engenders a mindset of normalcy, with little expectation of actual emergencies. This conditioned expectation of normalcy can create a heightened stress response when some unexpected, novel, or emergency event does occur. Pilot reactions vary widely in such circumstances with instances of startle, freezing (dissociation) and denial evident in some cases. An analysis of various aircraft incidents and accidents is made where evidence of stress induced inaction has resulted in undesired aircraft states. Previous experience of novel and emergency events has a moderating effect on arousal levels and is therefore likely to create less likelihood of inaction type behaviours due to stress. Implications for further research and future training are discussed.