2.1. OBJECTIVE MEASUREMENT CAMPAIGNS
2.1.1. ALERTNESS LEVELS AND DECREMENTS IN LONG-HAUL TECHNICAL CREWS
PERIODS CHARACTERIZED BY ALERTNESS DECREMENTS OCCUR FREQUENTLY: UP TO 15 % OF ACTIVE DUTY TIME SPENT IN COCKPIT
These periods are predominantly observed:
– during transatlantic (Europe-North America) and north-south flights with non-augmented crews, somewhat less frequently on transcontinental flights (Europe-Asia),
– during quiet cruise phases, when the crew is not engaged in any specific activity (monitoring),
– immediately after meals or snacks,
– during periods favouring sleep (11pm – 1am and 1pm – 3pm).
They often occur:
– simultaneously for both pilots, even for basic non-augmented crews,
– during critical phases (e.g. descent) or when the crew is performing tasks related to flight management (i.e. radar control, etc.).
These are reduced under certain circumstances:
– verbal communications,
– motor activities associated with mental tasks, for example, navigation management (i.e. FMS).
Observing the crew’s activity reveals a spontaneous tendency to synchronize periods of activity and rest which can explain the occurrence of simultaneous alertness decrements. In addition, the mutual knowledge that the pilots may have of the aircraft and the sector may contribute towards reducing the alertness levels.
2.1.2. LAYOVER SLEEP DURATION AND QUALITY
SLEEPING DURATION AND QUALITY ARE REDUCED BY JET-LAG AND NIGHT FLIGHTS
The following is observed:
– extensive sleep loss related to night flights,
– layover sleep, timing, duration and quality are not significantly affected on transatlantic rotations when the outbound flights are made during daytime,
– rebound effects on layover sleep for rotations comprising night-time outbound flights eastwards-westwards. An increase in the duration and a reduction in the quality of sleep leading to very frequent awakenings typically characterize a rebound effect.
2.1.3. DURATION AND QUALITY OF IN-FLIGHT SLEEP WITH AUGMENTED CREWS
THE DURATION AND QUALITY OF IN-FLIGHT SLEEP DEPEND ON THE PREVIOUS PERIOD SLEEP AND ON THE REST TIME SCHEDULING IN FLIGHT 中國航空網 www.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：Getting to grips with Fatigue & Alertness Management(9)
