Motion sickness arises from a conflict between visual, vestibular, and proprioceptive inputs that the brain cannot resolve.
Symptoms
- Nausea, vomiting
- Pallor, cold sweat
- Dizziness, headache
- Apathy, reduced performance
- In severe cases: inability to fly
Common triggers in flight
| Situation | Mechanism |
|---|---|
| Turbulence | irregular vertical / lateral accelerations |
| Steep turns, aerobatic | strong g changes |
| Reading / chart work without outside reference | visual-vestibular conflict |
| Heat, poor ventilation | promotes nausea |
| Heavy meal before flight | raises susceptibility |
| Hunger | equally unfavourable |
| Fatigue / stress | raises susceptibility |
| Fear, lack of motivation | increases probability of airsickness (for pilot AND passengers) |
Pilot countermeasures
| Measure | Effect |
|---|---|
| Look at the horizon | Sync visual with vestibular inputs |
| Smooth control inputs | Reduce accelerations |
| Fresh air / ventilation | Reduce nausea |
| Meal 1–2 h pre-flight | Eat modestly, easy to digest, no fatty/spicy food |
| Hydration | Water, no alcohol, little coffee |
| Keep head still | Avoid Coriolis |
Flicker vertigo
Flicker vertigo is a special form of vestibular-visual irritation from regular light flashes typically at 4–20 Hz.
Cockpit triggers
- Anti-collision strobe lights on entering cloud or fog: the aircraft's own strobe reflects from the cloud wall → fast repetitive flicker in cockpit.
- Propeller at low sun angle: sun is "chopped" by the propeller.
- Rotor blades on helicopters.
Symptoms
- Dizziness, nausea.
- Very rarely a photo-convulsive reaction in predisposed individuals.
Countermeasures
- Switch off strobe lights when entering IMC / dense cloud.
- Look away from the flickering area (e.g. sun through propeller).
- Change heading away from the sun.
Passengers with motion sickness — pilot responsibility
As PPL PIC:
- Ask before the flight whether the passenger is prone to motion sickness; if at risk: preventive medication (by passenger, not pilot).
- Provide sick bags in case.
- Smooth approach, smooth turns, allow horizon view — avoid steep bank angles and rapid direction changes.
- Adjust cabin temperature — not too warm; good ventilation is decisive.
- Passenger should watch the horizon, not stare into cockpit / at chart.
- On acute nausea: fresh air, descend to smoother altitude, land if necessary.
Medication — caution!
| Substance | Pilot compatibility |
|---|---|
| Dimenhydrinate (e.g. travel pills) | Not for active pilots — sedates, drowsy |
| Scopolamine (patch) | Not for active pilots — visual / attention disturbances |
| Ginger (natural, tea / tablets) | Often helpful, no sedating effect — fine before flight |
| Acupressure bands | Established natural method, no risks |
Important: most anti-motion-sickness drugs are classified under Part-MED as "incompatible with flying". For self-medication with OTC travel pills: at least 24 h pause before flying, or consult an aeromedical examiner.
Habituation
With increasing flight experience the system adapts — most pilots have significantly fewer problems after 20–50 flight hours.