Circadian Rhythm
Definition
The body natural 24-hour biological clock that regulates sleep-wake cycles. Disruption from jet lag, night flying, or irregular schedules increases fatigue risk and degrades cognitive performance.
Why Circadian Rhythm Matters for Pilots
Understanding Circadian Rhythm is important for pilot certification exams and safe flight operations. This concept appears on FAA and EASA knowledge tests, and examiners may ask about it during oral checkrides. A thorough understanding of Circadian Rhythm helps you make better decisions in the cockpit.
Exam Tip
This concept is commonly tested in human-factors-related questions on FAA and EASA exams. Make sure you can explain Circadian Rhythm in your own words for the oral exam. Practice applying this concept to real-world scenarios, not just memorizing the definition.
Related Terms
Share this with a fellow pilot
Related Content
Taxiway Markings
Aviation glossary definition and exam tips.
Minimum Fuel
Aviation glossary definition and exam tips.
Noise Abatement
Aviation glossary definition and exam tips.
ATPL Theory Complete Guide
Master every subject covered in airline pilot exams.
Free Practice Exam
Test your aviation knowledge with real exam questions.
Built by a commercial pilot
Pass your written for $39 — every track, 60 days
Circadian Rhythm is one of 5,500+ exam topics in the All-5 Bundle: PPL / IR / CPL / ATPL / Part 107 / TAE. One-time payment, no subscription. Free 30-day extension if you fail your real exam.
Test your knowledge
Think you understand Circadian Rhythm? Challenge yourself with practice questions covering human-factors and all other exam subjects.
Try Free Practice QuestionsMore Human-factors Terms
Situational Awareness(SA)
A pilot mental model of what is happening around the aircraft, including positio...
Spatial Disorientation
The inability to correctly determine aircraft attitude or motion relative to the...
Hypoxia
A condition of insufficient oxygen reaching body tissues, causing impaired judgm...
Time of Useful Consciousness(TUC)
The time from loss of oxygen supply until a person can no longer take corrective...
Would you pass the real exam right now?
Take a free practice quiz — real FAA-style questions, instant score. No signup to start.
Take the free quiz →