Spatial Disorientation
Following a chat amongst us today about helicopter crashes and spatial problems I thought I would post this article as a thought provoker to all of us who fly and maybe have not considered the problem enough since our PPL days or who have been flying so long we think we are too experienced to get into trouble.
How long can a pilot who has little or no instrument training expect to live after he flies into bad weather and loses visual contact? Researchers at the University of Illinois did some tests and came up with some very interesting data. Twenty student "guinea pigs" flew into simulated instrument weather, and all went into graveyard spirals or rollercoasters. The outcome differed in only one respect - the time required till control was lost. The interval ranged from 480 seconds to 20 seconds. The average time was 178 seconds -- two seconds short of three minutes.
Here's the fatal scenario. . . . . . .
The sky is overcast and the visibility is poor. That reported five mile visibility looks more like two, and you can't judge the height of the overcast. Your altimeter tells you that you are at 1500 feet but your map tells you that there's local terrain as high as 1200 feet. There might be a tower nearby because you're not sure how far off course you are. But you've flown into worse weather than this, so press on.
You find yourself unconsciously easing back just a bit on the controls to clear those towers. With no warning, you're in the soup. You peer so hard into the milky white mist that your eyes hurt. You fight the feeling in your stomach. You try to swallow, only to find your mouth dry. Now you realize you should have waited for better weather. The appointment was important, but not all that important. Somewhere a voice is saying, "You've had it -- it's all over!"
You now have 178 seconds to live.
Your aircraft feels on even keel but your compass turns slowly. You push a little rudder and add a little pressure on the controls to stop the turn but this feels unnatural and you return the controls to their original position. This feels better but now your compass is turning a little faster and your airspeed is increasing slightly. You scan your instruments for help but what you see looks somewhat unfamiliar. You're sure that this is just a bad spot. You'll break out in a few minutes. (But you don't have a few minutes left. . .)
You now have 100 seconds to live.
You glance at your altimeter and you are shocked to see it unwinding. You're already down to 1200 feet. Instinctively, you pull back on the controls but the altimeter still unwinds. The engine is into the red and the airspeed, nearly so.
You have 45 seconds to live.
Now you're sweating and shaking. There must be something wrong with the controls; pulling back only moves the airspeed indicator further into the red. You can hear the wind tearing at the aircraft.
You are about to meet your Maker; you have 10 seconds to live.
Suddenly you see the ground. The trees rush up at you. You can see the horizon if you turn your head far enough but it's at a weird angle -- you're almost inverted. You open your mouth to scream but. . . . . .
. . . .You just ran out of seconds.
Think about it before you press on into marginal weather
This Test was carried out with a Fixed wing, I have been told that for a rotary the average time is reduced to just THIRTY seconds.