Scientific evidence
To expect flight and cabin crew to have the same attendance as Jo Blog who delivers the post Mon-Fri 9-5 is completely unrealistic and possibly dangerous.There is a high level of alertness required on either side of the flight deck door to operate safely.The consequences of not being "with it" when operating as a crew member could be far more serious than Jo Blog giving back incorrect change at the till...Not sure if many on here are aware of the Moebus report commissioned by the EASA to evaluate fatigue/stress/alertness in both flight and cabin crew.
"Tasks of Flight attendants (FAs) require a sufficiently high level of alertness and
cognitive performance to ensure safety and adequate response especially in nonroutine
situations. From the viewpoint of general health and physiological needs, the same
requirements for cockpit and cabin crew should be applied. It has been shown [Vejvoda M
et al. 2000] that the fatigue levels of cabin crew towards the end of flight duty period
tend to be much higher than those of cockpit crew. In addition, flight attendants have
reported increased perceived stress and workload due to changes in duties and
responsibilities since “9/11” [Nesthus T et al. 2007]. This result from a study among US
cabin crew appears equally applicable to European cabin crew and may further contribute
to higher fatigue levels.
It can be assumed that during onboard service periods, hypoxia is more severe in cabin
crew than in cockpit crew. Although the resting SaO2 is well preserved up to ~2400 m
(max. cabin altitude), the drop in PaO2 decreases the diffusion of oxygen from the lungs to
the blood and then from the blood to the cells. This decrease in oxygen diffusion rate
becomes apparent during physical activities as an arterial oxygen desaturation at altitudes
as low as 1000 m [Muza SR et al, 2004; Mollard P et al, 2006]. FAs’ duties include
considerably more physical activities than those of pilots. The high heart rate values that
are recorded from cabin crew are usually associated with hard physical workloads [Vejvoda
M et al, 2000]. This may be an additional cause of fatigue in cabin crew.
The task of cabin crew contains safety aspects such as identification and management of
non regular in-flight situations. These comprise e.g. insidious hypoxia (loss of cabin
pressure), fire on board, weather conditions, handling of medical events, and unruly
passengers etc. Furthermore, it is generally accepted that the performance of cabin crew is
of crucial importance to safety in emergency situations. Fatigue and lowered alertness in
cabin crew may have negative effects on safety, although the degree of these effects is a
matter of ongoing discussions. However, normal pre- and in-flight duties and passenger
services also require adequate performance of cabin crew (an extensive description of flight
attendant duties is given by Nesthus et al.2007).
Although the hazards of impaired functioning of cabin crew may differ from those of
dysfunctioning cockpit crew, the maintenance of optimal alertness and performance of
cabin crew is of crucial importance. Therefore, the same duty and rest requirements should
be applied for both cockpit crew and cabin crew (e.g. see answers to questions 11 and 12)."