Definition
A short-lived episode in which part of the nervous system stops working normally, producing symptoms such as fainting, loss of consciousness, seizure, paralysis, or sudden disturbance of vision, balance, or sensation, with full recovery afterward. In FAA medical certification, any such episode — even if it resolved completely and the cause is unknown — is a disqualifying medical history item that must be reported and reviewed.
Plain English
A brief episode where the brain or nerves suddenly fail to do their job — for example, you pass out, have a seizure, briefly can't move a limb, or lose vision — and then recover. The FAA treats any event like this as a serious red flag for medical certification, even if you feel completely fine now.
Context Anchor
Seen in medical certificate discussions, especially when the FAA or an aviation medical examiner reviews a history of fainting, seizures, sudden weakness, or other unexplained neurological events.
Derivation
Transient means short-lived or passing. The phrase describes any temporary failure of nervous system control — the nervous system being the brain, spinal cord, and nerves that run the body. Knowing 'transient' just means 'brief' helps clarify that the FAA is not only concerned with permanent conditions; even a one-time event counts.
Why Pilots Care
Any history of such an event must be disclosed on the medical application and may require additional evaluation before a certificate can be issued.
Grounding Statement
A pilot may recover completely after the episode, but the safety question is what happened during it and whether it could recur while flying.
Intuition Check
“Transient” does not mean harmless; it means temporary. A temporary loss of nervous system function can still be medically serious for flying.
Example Sentence 1
Because he had fainted once during a blood draw in college, his AME flagged it as a transient loss of control of nervous system function and required a neurology report before issuing the medical.
Example Sentence 2
The examiner asked follow-up questions about the transient loss of control of nervous system function noted in the medical records.