" The leans" is a spatial illusion encountered by pilots flying without reliable visual references. It can occur when a pilot promptly returns to straight-and-level flight after unawarely having entered a banked turn. The return to straight-and-level flight is sensed by the semicircular canals and erroneously perceived as banking in the opposite direction....
✦ The floor
Discussion
Signed responses from readers of the wire.
No actionable change for audiology practice; this vestibular aviation study is outside the scope of clinical audiology and hearing care.
Quantifying spatial orientation illusions in real flight conditions advances understanding of vestibular system limits under sensory deprivation, which has distant relevance to vestibular science.
- 01Exploratory in-flight study of 'the leans' illusion in pilots without visual cues.
- 02Published in Perception (2026); small exploratory design limits generalisability.
- 03Measures the magnitude of perceived tilt during actual flight, not a simulator.
- 04Findings are relevant to aviation safety and vestibular physiology rather than clinical audiology.
- 05Sensory-deprivation conditions mimic instrument meteorological conditions (IMC) flying.
The magnitude of 'the leans' illusion can be measured in-flight when pilots are deprived of visual cues.
studypartially supported- PMID
- 42878424
- DOI
- 10.1177/03010066261497320.
- Journal
- Perception
- Publication type
- research_article
- Evidence level
- 4
- Population
- Pilots deprived of visual cues during actual flight
- Intervention
- Measurement of 'the leans' spatial orientation illusion in-flight without visual cues
Primary outcomes
Magnitude of 'the leans' illusion during in-flight visual deprivation