Page 29 - Volume 17 Number 11

eventually to a point of neutrality. The system tricks us when we stimulate the semicircular canals to a point of neutrality, and then stop the acceleration. The illusion is a sensation of movement in the opposite direction and is often called the leans. If in IMC, a graveyard spiral can result from this auditory system illusion.Kinesthetic is our sense of gravity and the relationship we perceive between our body parts. This is what makes a turn feel like a climb. One illusion affecting us IFR folks is caused by executing a missed approach. As we put the coal to the motors and begin a climb, the combination of acceleration from the engines and the pitch change, from a few degrees nose-down to a few degrees nose-up, can feel like a steep climb or a turn. Both our kinesthetic and auditory systems are receiving data. Combine this with an actual turn during the procedure and the sensation can be disorienting, to say the least. The final straw in this scenario is this: very seldom do we accomplish IMC go-arounds or missed approaches. The lack of experience greatly diminishes the ability of both the comparator and learning components of our brain to recognize the illusions created by this maneuver.Minimal jarringLanding is one of purest seat-of- the-pants maneuvers. Unless we are flying Cat II and III approaches to an auto-landing, our senses are what garner us the great landing comments from fellow aviators and passengers. Our vision, especially our peripheral vision, as well as our sense of balance from the inner ear, provides the main references during a visual landing. We like great landings because they demonstrate the skill and finesse required when integrating our seat-of-the-pants senses---with minimal jarring. Our senses work just fine when flying an airplane and we should use them. We simply must recognize illusionswhen they occur and use alternate sources of data when appropriate and available.We’re required to have pitot-static checks performed on our systems to make sure those components are both correct and reliable. You may, however, catch these non- human systems with their electronic britches down. This is where the plural in “trust your instruments” comes in. The classic culprit in our training scenarios is a vacuum system or instrument failure. We have all been taught to verify what we are seeing in the instruments by cross checking with other sources: two artificial horizons, or one and a VSI / IVSI, altimeter or HSI, for example. Just as in the case of an engine failure, we don’t want to start making corrections until we verify that our data and assumptions are correct. It may take a few seconds to discover which instruments are lying, but it will be time well spent.We don’t need no stinkin’ instrumentsAs pilots, we have misused the information from our physical senses so routinely that we’re taught to all but ignore our senses and instincts. I suggest we don’t entirely throw away the sensations of flight by substituting electronics and mechanical things for seat-of-the-pants sensations. It’s the stimulation of our senses, after all, that makes flying, well, flying. And if they didn’t expect us to use our senses to fly airplanes, our flight physicals wouldn’t include a check of our vision, hearing and balance, right? We can learn to recognize and ignore illusions through experience. Here’s an example, once again at thetraffic light. When the car next to us, instead of moving backwards, starts to creep forward, we are not disoriented like we were before. We recognize this direction of movement as the person next to us anticipating that the light is about to turn green and we do not push on the brakes thinking that we are the one moving; we have learned to recognize the illusion.SeamlesslyNone of us are natural born pilots; we have to practice to become good at it. Once we have the experience, judgment and instinct to seamlessly fuse the flight instruments into our bio-mechanical interaction with the machine, seat-of-the-pants senses can be safely used to slip the surly bonds of earth. It’s a matter of recognizing illusions before they create spatial disorientation; that lands us in someone’sbarbeque grill. T&T •Kevin Dingman has been flying for 40 years. He’s an ATP typed in the B737 and DC9 with 19,000 hours. A retired Air Force Major, he flew the F-16 then performed as a USAF Civil Air Patrol Liaison Offi- cer. He flies volunteer missions for the Christian organization Wings of Mercy, is employed by a major airline, and owns and operates a Beechcraft Duke. Contact Kevin at Dinger10d@gmail.com.NOVEMBER 2013 TWIN & TURBINE • 27