In 2020, Azul Linhas Aéreas Brasileiras embarked on record-setting humanitarian relief flights from Brazil to China for which there was no prior precedence.

​

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.