White Papers
SAFTE-FAST Combined Capacity Metric
The SAFTE-FAST model estimates fatigue based on prior sleep duration and circadian rhythms or time of day. However, fatigue can also result from workload. In SAFTE-FAST, workload associated with a duty or series of duties is conceptualized as a collection of operational factors that influence the cognitive demands on the pilot.
This white paper explores the SAFTE-FAST Combined Capacity Metric for evaluating fatigue risk in operational settings. This metric represents cases in which work demands exceed cognitive capacity. Combined Capacity is an average of Effectiveness, Sleep Reservoir, and Workload. Low Combined Capacity scores indicate cases of high compound fatigue risk.
SAFTE-FAST as a Supporting Tool for Fatigue Investigation
Looking at work schedule data, time of day, and sleep history, SAFTE-FAST can provide a picture of the fatigue risk during a work-related incident.
This white paper describes, in general terms, how to use SAFTE-FAST to estimate fatigue risk to determine whether fatigue should be considered a contributing factor during a safety investigation.
Sleep and Fatigue During Covid-19 Humanitarian Missions
In 2020, Azul Linhas Aéreas Brasileiras embarked on record-setting humanitarian relief flights from Brazil to China for which there was no prior precedence.
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Modeling in SAFTE-FAST was used to determine optimal departure times considering high levels of alertness, high sleep reservoir, and alignment with circadian interactions. SAFTE-FAST was also used to predict in-flight rest opportunities from best to worst-case scenarios. During the flights, the volunteer crew kept personal sleep diaries and wore IBR’s Zulu Watch to collect actual sleep data.
Workload Calculator
Our workload calculator was defined to be validated with subjective rating tools like the NASA TLX scale. Download our Workload White Paper to learn more.
Zulu Watch Validation
Read how our Zulu Watch compared to polysomnography and see why airlines have adopted the Zulu Watch as a means to collect actual sleep data.