← All explained questions · Supplemental · XI — Night Operations

A pilot enters a SOMATOGRAVIC ILLUSION on a night takeoff. Symptoms typically include

Choices

✓ perceived nose-up sensation during forward acceleration on rotation.correct
The somatogravic illusion feels like a nose-up pitch during forward acceleration on rotation, leading to instinctive nose-down input that risks impact with terrain. Somatogravic illusion: linear acceleration (e.g., night takeoff) tilts the otolith organs in the inner ear, producing a false PITCH-UP sensation. The pilot, lacking outside reference, instinctively pushes forward — descending into terrain. Trust the attitude indicator. This illusion is responsible for many night takeoff accidents.
perceived bank when straight and level.
That's the leans (vestibular).
loss of color perception.
Color loss is normal night vision (rod cells are colorblind).
ears popping painfully.
Ear pressure is barotrauma, not somatogravic.

Why

The somatogravic illusion feels like a nose-up pitch during forward acceleration on rotation, leading to instinctive nose-down input that risks impact with terrain. Somatogravic illusion: linear acceleration (e.g., night takeoff) tilts the otolith organs in the inner ear, producing a false PITCH-UP sensation. The pilot, lacking outside reference, instinctively pushes forward — descending into terrain. Trust the attitude indicator. This illusion is responsible for many night takeoff accidents.

FAA source: PHAK Ch 17, AIM 8-1-5browse the reference library →

Covered in Supplemental · XI — Night Operations — study the lessons free, then practice with grading and mastery tracking.

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Original study question written for this course — representative of FAA knowledge-test topics, not an actual current FAA exam question. Reviewed by a panel of three CFIs + AI review.