0255 Comparing Performance, Fatigue and Sleepiness Between Short-Haul And Ultra Long-Haul Commercial Airline Operations

Abstract

Abstract Introduction Safety performance indicators (SPIs) are used in aviation to determine if a trip that is non-compliant with federal regulations is safe to fly. Exemptions to regulations can be granted if a safety case demonstrates that the SPIs for an alternative means of compliance (AMOC; i.e., a trip outside regulations) are non-inferior to SPIs for a safety standard operation (SSO; i.e. a trip compliant with regulations). Through this process, it has previously been suggested that ultra-long-range flights are non-inferior to long-range flights due to increased sleep opportunity. We determined whether SPIs for non-compliant ultra-long-range (ULR) trips are non-inferior to those for compliant short-haul (SH) trips. Methods Performance, fatigue, and sleepiness were assessed at the top of descent (TOD) of flight segments using the Psychomotor Vigilance Task (PVT), Samn-Perelli (SP) fatigue scale, and Karolinska Sleepiness Scale (KSS), respectively. Data were analyzed using non-inferiority testing. Two different ULR trips with different TOD times (ULR trip 1: n=81; ULR trip 2: n=22) were compared to two types of SH trips, including one trip that contained one or more all-night flights (SH trip 1: n=48) and one trip with zero all-night flights (SH trip 2: n=47). Results Non-inferiority was found for the SPIs at most comparison points. For example, comparing the SPIs for ULR trip 2 and SH trip 1 at final TOD, non-inferiority was found for all SPIs. In contrast, comparing the SPIs for ULR trip 1 and SH trip 1 at final TOD, non-inferiority was found for SP and KSS, while non-inferiority for PVT was only suggested. Conclusion The findings suggest that the AMOC trips are as safe as or safer than the compliant SH trips. This raises questions regarding the structure of SH trips and how differences in the structures play a role in performance, fatigue and sleepiness. Support United Airlines