← All explained questions · Supplemental · VIII — Basic Instrument Maneuvers
The 'leans' is a vestibular illusion that occurs when
Choices
the airplane is low on fuel on one side.
Fuel imbalance is a different problem.
✓ after an unrecognized slow roll into a bank, the pilot returns to wings-level via instruments but the inner ear.correct
which adapted to the bank) feels they are now banked the OPPOSITE direction. The pilot wants to bank back into the original direction, which is wrong. The leans: most common spatial disorientation illusion. A slow, unrecognized bank entry adapts the vestibular system to feeling level. Returning to true wings-level via instruments then feels like banking the OPPOSITE direction — the body wants to lean back into the (false) wings-level. Cure: trust the AI, hold wings level until vestibular adaptation passes (~30 sec to several minutes).
the engine is running rough.
Engine roughness isn't a vestibular illusion.
the cabin is depressurized.
Depressurization issues are physical, not vestibular illusions.
Why
which adapted to the bank) feels they are now banked the OPPOSITE direction. The pilot wants to bank back into the original direction, which is wrong. The leans: most common spatial disorientation illusion. A slow, unrecognized bank entry adapts the vestibular system to feeling level. Returning to true wings-level via instruments then feels like banking the OPPOSITE direction — the body wants to lean back into the (false) wings-level. Cure: trust the AI, hold wings level until vestibular adaptation passes (~30 sec to several minutes).
FAA source: PHAK Ch 17, AIM 8-1-5; PHAK Chapter 17 — Aeromedical Factorsbrowse the reference library →
Original study question written for this course — representative of FAA knowledge-test topics, not an actual current FAA exam question.