Private Pilot Licence · Practice

At what altitude does hypoxia typically become a concern for an unpressurised VFR aircraft, and what are the early symptoms?

• A.Hypoxia symptoms can begin above 10 000 ft (3 000 m) AMSL
• B.Hypoxia only affects pilots above FL350 (35 000 ft) — well above VFR limits
• C.Hypoxia only affects pilots who are unfit
• D.The symptom threshold is 25 000 ft for day VFR