Safety Tip: Surviving Spatial Disorientation

In dealing with Spatial Disorientation there is said to be two categories of pilots: the ones that have experienced it and the ones that will.

The Stonecipher study indicated that the average life expectancy of a non-instrument rated pilot in IMC was 178 seconds from the onset to loss of control due to Spatial Disorientation. Of the 20 subjects tested, 19 entered graveyard spirals and the 20th whip stalled. None of them lasted over 8 minutes and all had the same skills training. Being a good pilot requires a blend of knowledge, skill and judgment. Dealing with disorientation involves a high level of all 3 competencies.

Most pilots during ground school are instructed about the drift of the inner ear, the tendency to believe that we are flying straight when we are actually turning. What most pilots are not taught, however, is if your hands are gripping the yoke during this time you'll unconsciously make inputs to roll the aircraft into an increasingly steep turn. The tighter you grip the yoke the greater the tendency to make unintended inputs. Your conscious motor reflexes will roll the airplane to what feels level -- but isn't. One misconception is that a disoriented pilot is unaware of the real attitude of the airplane, this is not necessarily true. Then, you might ask, why not simply roll out to level flight? During disorientation your conscious mind can't break the hold of unconscious reflexes with an extremely tight grip on the yoke. In other words, your muscles freeze in position. Thus, if you find yourself in this situation the first and most important thing you can do is let go of the yoke. (Of course, letting go of the yoke will not seem like a good idea if you are used to flying out of trim) Also remove your feet from the rudder pedals. This will break the stigma between the conscious and the unconscious reflexes. Now that your hands are off the yoke, look at the turn coordinator, step on the high wing with firm rudder pressure until you zero the rate of turn. Once the turn has stopped if left alone the aircraft will execute a series of climbs and dives called a Phugoid oscillation, which you can stop by gently but firmly pitching to the horizon on the AI, or oppose the VSI needle to return the pitch to level and stop oscillations. Remember, control the yoke with an open hand, otherwise gripping the yoke could start the whole process over again.

To reduce the vulnerability to Spatial Disorientation:

• develop the habit of flying in perfect trim
• try flying with your forefingers and thumb
• learn to fly without moving your head
• don't fly with a cold or any condition that would disturb the inner ear
• get as much actual IMC with a CFII as you feel necessary

Better yet, get an instrument rating and remain proficient!

After acquiring your private license if you are not planning on getting your instrument rating,. we strongly recommend getting at least 10 to 15 hours of instrument training in case you accidentally end up in IMC.

Reference: WCFC Ground School; WCFC CFII input; Plane and Pilot Magazine, May 2003

These safety tips are provided by the WCFC Safety Committee. They are intended to stimulate thought and discussion about flight safety and do not necessarily represent club policy nor are they intended to replace instruction from a qualified instructor.