Spatial Disorientation (SD) and Resignation in the cockpit


“Spatial Disorientation is an individual’s inaccurate perception of position, attitude, and motion relative to the center of the earth. When it occurs, pilots are unable to see, believe, interpret, or process the information on the flight instruments. Instead, they rely on the false information their senses provide.”

I believe SD is one of GA’s least understood hazards to safe flight.

The USAF believes we all are susceptible to these illusions that “are the result of innate physiological and perceptual process and training as such would not be expected to eliminate their occurrence. Dealing with the illusions once they occur is an issue that can be improved by increased training whether in ground-based devices or in an airborne environment.”

According to the National Transportation Safety Board online accident database

U.S. Air Force web site for SD

Sporty’s Safety Quiz on SD is at … s&QuizId=5

Wikipedia excellant discussion and links

Pilot and Plane discussion of SD … ation.html


Takeoff over unlit ground or water can be particularly dangerous, even to high time pilots, if there are few visual ground references. There are many accidents on record where the departing pilot crashed on takeoff by descending into the ground, usually within the first mile of departing the airport. How could a pilot, much less an experienced one, crash like this?

The answer is in the somatogravic illusion, which is discussed in most instrument training classes but is rarely mentioned in night training for private pilots. According to the FAA Instrument Flying Handbook, “… a rapid acceleration, such as experienced during takeoff, stimulates the otolith organs in the same way as tilting the head backwards. This action creates the somatogravic illusion of being in a nose-up attitude, especially in situations without good visual references. The disoriented pilot may push the aircraft into a nose-low or dive attitude. A rapid deceleration by quick reduction of the throttle(s) can have the opposite effect, with the disoriented pilot pulling the aircraft into a nose-up or stall attitude.”

So what happens? A pilot taking off at night will experience the acceleration as a climb and release yoke pressure, allowing the airplane to descend into terrain. The same thing occurs often when instrument pilots reach the missed approach point and add full power to do a go-around. They perceive the acceleration as a climb and then – rather than pitch and trim for climb at Vy – continue to fly level at the worst possible time: close to the ground and possibly in IMC conditions.


Low visibility (night/haze/IMC) contributes to JFK Jr.'s accident.

Much has been published about this tragic accident; this AOPA article details how events quickly evolved beyond the capabilities of his experience.



Youre in a pickle, a real fix of a situation and you have been racking your brain searching for a logical solution. The question is, do you resign yourself to fate; or do you dig deep into the recesses of all you have ever learned to fly onto another day of blue skies. Bob Miller, ATP, CFII illustrates Lateral vs. Logical Thinking Skills with the following explanatory tale.

Many years ago in a small Indian village, a farmer had the misfortune of owing a large sum of money to a village moneylender. The moneylender, who was old and ugly, fancied the farmer’s beautiful daughter. So he proposed a bargain. He said he would forgo the farmer’s debt if he could marry his daughter.

Both the farmer and his daughter were horrified by the proposal. So the cunning money-lender suggested that they let providence decide the matter. He told them that he would put a black pebble and a white pebble into an empty money bag. Then the girl would have to pick one pebble from the bag.

            1) If she picked the black pebble, she would become his wife and her father's debt would be forgiven.

            2) If she picked the white pebble she need not marry him and her father's debt would still be forgiven.

            3) But if she refused to pick a pebble, her father would be thrown into jail.

They were standing on a pebble strewn path in the farmer’s field. As they talked, the moneylender bent over to pick up two pebbles. As he picked them up, the sharp-eyed girl noticed that he had picked up two black pebbles and put them into the bag. He then asked the girl to pick a pebble from the bag.

What’s A Girl Supposed to DO?

Now, imagine that you were standing in the field. What would you have done if you were the girl? If you had to advise her, what would you have told her? Careful analysis would produce three possibilities:

    1. The girl should refuse to take a pebble.

    2. The girl should show that there were two black pebbles in the bag and expose the money-lender as a cheat.

    3. The girl should pick a black pebble and sacrifice herself in order to save her father from his debt and imprisonment.

This story is illustrative of the difference between lateral and logical thinking. The girl’s dilemma cannot be solved with logical thinking.

Using lateral thinking to solve the problem, the girl put her hand into the moneybag and drew out a pebble. Without looking at it, she fumbled and let it fall onto the pebble-strewn path where it immediately became lost among all the other pebbles. “Oh, how clumsy of me,” she said. “But never mind, if you look into the bag for the one that is left, you will be able to tell which pebble I picked.” Since the remaining pebble is black, it must be assumed that she had picked the white one. And since the money-lender dared not admit his dishonesty, the girl changed what seemed an impossible situation into an extremely advantageous one.


Most complex problems do have a solution. Traditional logical thinking among pilots draws upon the rote lessons we learned in the typical training environment. Hopefully, all of the things we were taught will cover every eventuality we might encounter in the sky. Ideally, our emergency checklists will provide a solution to even the nastiest emergency we might encounter. But what if this is not true? What if we have exhausted all of the LOGICAL solutions? We suffer a psychological event called RESIGNATION. We resign ourselves to the ultimate fate of our emergency . . . we give up and die.

Lateral thinking is not taught in most traditional flight training programs. Without the ability to engage in lateral thinking, we focus on LOGICAL solutions. Had the farmer’s daughter engaged in logical thinking, any choice she made would have been unpleasant. A quick recollection of Captain Al Haines’ remarkable landing of the catastrophically disabled United Flight 232 in 1989 is an example of lateral thinking. There were no emergency checklists addressing the simultaneous loss of all three independent hydraulic systems in the DC-10 . . . because the odds for such an event occurring were greater than a billion to one! Captain Haines and his crew effectively re-wrote the book on crew resource management by applying lateral thinking to their in-flight emergency.

In Ch. 13, page 142 of his Adventures in Flight, Mr. Miller also referrers to RESIGNATION as a contributing factor in John F. Kennedys, Jr. death spiral into the Atlantic.

For a discussion of Lateral Thinking see the following sites.


Amen! Excellent points!


"Night VFR is an oxymoron and the FAA should consider regulating (to some degree) such flying for pilots who do not possess an instrument rating. A pilot cannot perceive as much visual information at night as he does during day VFR conditions. Most of the information that is not perceived at night is peripheral visual information (or ambient vision). Ambient vision is sensitive to flat planes (i.e. the horizon) and motion cues, and is processed by the preconscious brain. Under day Visual Meteorological Conditions (VMC), the pilot specifically uses ambient visual information (whether he realizes it or not) to judge and maintain proper aircraft attitude. Since this information is processed by the preconscious brain and the task of wings level flying is a learned skill that can be executed by the preconscious brain, this activity does not result in a load on the limited capacity, conscious brain.

At night, much of the ambient visual information is absent. Also, the potential for other visual illusions (false horizon or indistinct horizon) is much higher. Since focal vision must be used to maintain aircraft attitude and focal vision is processed by the conscious brain; a slow and serial processor. The conscious brain can quickly become overwhelmed (task saturation) and important situational awareness cues (i.e., altitude, descent rate, etc…) can be missed. The most susceptible pilots are those who are not trained to operate in these (limited visibility) conditions trained or a pilot who has been trained, but is not current."

this is an short excerpt from ANN Guest Columnist Dick Leland


When I was flying out of Las Vegas, I would often take off at night and fly south across the desert when the sky was clear and often times there was no way I could pick out a horizon among the miriad mountains that surround the Colorado River. That was when I quickly became very thankful for the constant IFR recurrancy and the plethera of hours under the hood!

When I moved to southern Texas I was looking forward to being able to actually fly VFR at night remembering the night flights I had growing up in Kansas. There the horizon was almost always visible and it was easy to fly from point a to point b as the cities and towns were close enough to be seen from each other. I quickly found out that A) cities and towns in Texas are not all that close to each other B) The ocean can really mess with your perspective and C) again, thank God for all those instrument hours and recurrancy.

With this in mind, I was speaking to our POI the other day about this very topic and I agree with his point. That is, 3 take off and landings every 90 days at night are fine for currency, that will definently get you off and on the ground safely. However, he believes the regulation ought to include a minimum of a fifty mile night leg with a T/O and LDG should be included in that regulation. Either that or an additional rating should be added for “Night VFR.” Since I am not a firm believer in adding more paperwork to an already overworked system, I think the former would work just fine. And, if it’s not a regulation, what’s one hour (more or less) of flight time on a beautiful, starry night when you’re in the mood for flying anyway? Might be something we could all add to our night currency.


research of existing literature suggest the condition most susceptible to SD is during a sudden and unexpected transition from VMC to IMC flight conditions. :bulb:


ANN’s Daily Aero-Tips (12.16.06): Lost In The Clouds Sat, 16 Dec '06
"The pilot entered Instrument Meteorological Conditions (IMC) and, while on vectors for an ILS approach and after experiencing “the leans”, recovered only to find he had lost situational awareness and did not know where he was on the approach. The pilot successfully flew the approach (of course, since we read his account), and provides some valuable advice for the instrument pilot."


for not much money (by aviation standards anyway), a portable GPS can effectively eliminate most of the problems with situational awareness. It almost feels like cheating because it makes instrument approaches, tracking airways, etc. so easy. Since they run on batteres, they also provide an emergency backup for several instruments in case of vacuum and/or electrical failure.


How would GPS help with sensory illusions like the ‘leans’ if I lose instrumentation? I would have altitude and speed, but without some sort of sense of attitude, I’ll still vector into the ground ( flat spin, stall etc…)


How would GPS help with sensory illusions like the ‘leans’ if I lose instrumentation? I would have altitude and speed, but without some sort of sense of attitude, I’ll still vector into the ground ( flat spin, stall etc…)

You are quite right that GPS doesn’t have any effect on the leans. If you read his post, you’ll note that he lost his situational awareness subsequent to having the leans:

while on vectors for an ILS approach and after experiencing “the leans”, recovered only to find he had lost situational awareness and did not know where he was on the approach.

A moving map GPS helps with that situational awareness so you can clearly see where you are on the approach.


Don’t forget the greatest thing about the latest GPS units - Terrain Awareness. Also, if you think you are straight and level, but the map is turning you know you better get on it.

Lastly, if navigation and position are easily handled, that’s less stress for the pilot and better all around.

Just don’t get so you NEED the GPS because you aren’t using your other skills. I recently took a VFR flight to brush up on pilotage. Nothing was in danger but my reputation as I almost violated class C airspace trying to use the map to determine position and frequencies. It was an eye opener.


There’s your problem, real pilots use charts not maps. Did you get your’s at Citgo? :wink:


Yeah! Where did you get your LICENSE??? :laughing:


Heh heh, quick check of the forums would easily reveal this answer. I even gave it.

But to be nice today, I will provide a link to the thread in question and the FAA link included in my posting. … 5&start=41



I have a number of licenses, including one that allows me to legally fly my airplane.

I have maps that help me navigate.

I have a reasonably good grasp of the english language, and since I left the military, I am allowed to use all of it. I earned it.

I have friends who actually like me.

If you don’t have any of these things, DON’T DESPAIR! It’s not too late.

When next at a large gathering with a bunch of “real” pilots. Stand up on a chair and tell everyone that “real” pilots don’t use maps from gas stations.

Report back here with your new found wisdom, and the names of your new friends. Growth is FUN!