This story is made in partnership with AOPA Pilot Protection Services. Ensure your certificates are safeguarded before your next flight. Find out more and get started here.
If you fly at night or in instrument conditions, it’s crucial to understand somatogravic illusion and how to conquer it.
What Is Somatogravic Illusion?
Somatogravic illusions occur during rapid acceleration and deceleration in flight. This illusion typically arises when exterior visibility is limited, and you rely on body sensations rather than actual flight instrument readings.
As you accelerate, your body perceives a pitch-up motion, so your natural reaction is to pitch down. The opposite occurs during deceleration, where deceleration is felt as a pitch-down motion, and your reaction is to pull back on the yoke to pitch up.
Although the illusion can happen during deceleration, one of the most common examples is during a go-around while flying in reduced visibility or at night. Imagine you’re conducting an instrument approach. When you reach decision altitude and the runway is out of sight, you add power for a go-around. You rapidly transition from a slow approach to an accelerating climb-out. You look down in the cockpit to adjust power, flaps, and landing gear settings. Unconsciously, you sense that you’re pitching up more than necessary, so you correct by pitching down, all without actually checking your attitude indicator. Seconds later, you find yourself with the nose pointing low and descending towards the ground.
So how can your body deceive you into making such a serious mistake so easily? It all boils down to how your inner ear functions.
Inner-Ear Sensations
Sensory information about motion, equilibrium, and spatial orientation is provided by the vestibular system and its associated parts in and around the ears.
Inside the utricle of the inner ear, there are tiny hairs that, as your body moves, detect motion by bending forward and backward. As you can see in the diagram below, the tilting motions of these hairs during acceleration and deceleration are the same as when you tilt your head forward or backward. That’s why when you accelerate and decelerate in the plane, your vestibular system tells your brain that you’ve entered a false flight attitude.
The Solution
To counteract the effects of somatogravic illusions, remember to check your instruments before reacting to a perceived flight attitude, especially during high workload and reduced visibility. Use your instrument scan pattern to keep your plane in a safe flight attitude and avoid making large, quick movements with your head.
What your body tells you isn’t always accurate, and the sensation of somatogravic illusion can be overwhelming at times. The phrase ‘trust your instruments’ may seem cliché, but it’s the best tool you have to overcome this in-flight illusion.
Have you ever experienced spatial disorientation in your own flying? Share your experience in the comments below.
Protect your certificate with AOPA Pilot Protection Services. Learn more and get started here.
Subscribe to the email and receive real-world flying tips and information directly in your inbox every week.
