# Flight Physiology ## Brain's Spatial Orientation Stack ### Vision ### Vestibular System ### Kinesthetic Sense ## Why We Need to Trust the Instruments ### Visual // optical Illusions - **F – False horizon** Sloping cloud layers, terrain, or lights create an incorrect visual reference that leads to an improper pitch or bank. - **A – Autokinesis** A stationary light in darkness appears to move, tempting the pilot to maneuver to “track” it. - **N – Narrow / wide runway illusion** Narrow runways appear farther away (leading to a low approach); wide runways appear closer (leading to a high approach). - **B – Black hole approach** Featureless terrain and few ground lights create the illusion of being high on approach, encouraging an unsafe descent. - **A – Approach slope illusion** Visual cues make a normal glidepath appear too high or too low, leading to improper pitch adjustments. - **T – Terrain / runway slope illusion** Up-sloping terrain/runway makes you feel high (fly low); down-sloping makes you feel low (fly high). ### Vestibular Illusions (CLIPES) - **C – Coriolis** Rapid head movement during a sustained turn stimulates multiple semicircular canals at once, creating an overwhelming sensation of tumbling or rolling. - **L – Leans** A slow, unnoticed bank feels level; correcting to true level flight creates the false sensation of banking the opposite direction. - **I – Inversion** Abrupt acceleration after a climb can create the sensation of tumbling backward, prompting a dangerous nose-down input. - **P – (Graveyard) sPiral** A prolonged, unnoticed turn feels level; when altitude is lost and the pilot pulls back, the tightening spiral increases descent and load factor. - **E – Elevator Illusion** Sudden vertical acceleration (updraft or downdraft) creates the sensation of pitching up or down. - **S – Somatogravic** Rapid linear acceleration (like takeoff) feels like excessive nose-up pitch; deceleration feels like pitching down. ## Hypoxia - ### Hypoxic Low **oxygen pressure** in the lungs → not enough O₂ enters the blood - ### Hypemic: Blood can’t **carry oxygen** effectively (carbon monoxide, anemia, blood loss)_ - ### Stagnant: Blood isn’t **circulating fast enough** to deliver oxygen (excessive G, shock) - ### Histotoxic: Cells **can’t use** the oxygen that’s delivered (alcohol, drugs) ### Prevention - Supplemental Oxygen: - 12,500 MSL after 30 mins, pilots must use O2 - 14,000 MSL: pilots must use oxygen continuously - 15,000 MSL: pilots must use oxygen continuously, must be provided to each occupant. ## Ear and Sinus Blockage ## Scuba Diving - Up to 8000 MSL - 12 hours after da dive that did not require controlled ascent - 24 hours if controlled ascent was required or decompression stop - Above 8000 MSL - 24 hours ## Hyperventilation - develops when too much carbon dioxide is eliminated from the body. - symptoms: drowsiness, dizziness, shortness of breath, feelings of suffocation, pale calmy appearacnce, myscle spasm. - Fix: slow breathing rate, talking aloud and breathing into paper bag ## Hypothermia ## Fitness for Flight ### Stress ### Fatigue ### Dehydration ### Alcohol and Drugs - No drugs - Do not fly within 8 hours of using alcohol or when BAC is 0.04% or greater. But seriously - don't drink and fly and ideally wait at least a full day or more to recover.