Short Haul Sleep Restriction

Sleep Restriction against Heightened Emotional Activity Results

This article provides a meta-analysis done on the original results researched by D. Arthur Drury, Sally A. Ferguson and Matthew J.W. Thomas from Centre for Sleep Research University of South Australia. These three researchers carried out a research about negative affective states; confusion, disagreement, unease, frustration and stress (Heightened Emotional Activity (HEM)) during short haul operations when pilot’s sleep has been restricted.

As you can see on Table 1, it shows that the captain and the first officer were likely to have at least 1 HEM problems (by calculating the probability of having at least 1 HEM) during their flight. Also, the more time they slept and prepared before their short haul flights, the likelihood of HEM decreased as well (Prior Wake more than 12 hours did not have any affect in the data).

Table 1: showing data results from the original article.

Research Methods

Research Approach
Quantitative Exploratory research about pilots (captain and first pilot) HEM during restricted sleep hours.

Observers collected data from pilots in 2009 during 302 normal flight sectors of commercial airline operations. This research was completely hidden from public and was only taken part if crews that were scheduled in this sector volunteers for it.

The researchers have divided the pilots as Captains who had flying experience of 15.8 years (SD=8.3) and First Officers who had flying experience of 8.3 years (SD=6.8). When Heightened Emotional Activity (HEM);
Confusion (A crew-member expresses some confusion with respect to the nature of the threat or its potential impact on the operation, such as not understanding the exact nature of a technical problem),
Disagreement (crew-members fail to agree with each other as to the nature or the potential consequence of the threat),
Unease (A crew-member expresses unease as a result of a threat, such as not being comfortable with continuation of an approach),
Frustration (A crew-member expresses anger or frustration as a result of a threat, such as becoming observably frustrated with a ground delay) and
Stress (A crew-member becomes noticeably stressed as a result of a threat, such as difficulty responding to and managing a gusty crosswind handling).
Occurs to captain or First Officer, the observers will take a note and record how many pilots had HEM during their short haul flight.

Data Analysis
This article has the mean value and the probability of pilots getting HEM as a whole other as just probability of getting each of the HEMS. The mean value will tell us the average Hem pilot felt during their flight. As there were two big extremes in most of the flights. The probability of having a disagreement was very low <0.005 most of the time and the probability of receiving a stress was very high as it is more likely to occur. Therefore, it is essential to know what the overall expected value is in order to find the average number of pilot’s feeling fatigue due to certain HEM.


1. D.Arthur Drury., Sally A. Ferguson & Matthew J.W. Thomas (2011). Restricted sleep and negative affective states in commercial pilots during short haul operations. Journal of Accident Analysis and Preventation (445), 2012, pages 80-84

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