Spatial Disorientation & Vertigo

ahkahn

ahkahn

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Hi all,

I've been a lurker for quite some time, and love to take it all in. I'm at the 200 hour mark and a few days shy of my instrument checkride. I'm really struggling to understand one concept, and I purposely posted this in the general forum because I believe the information is pertinent to ALL pilots, IR, PP, or student. Murphy is telling me not to bring this up, because as soon as I mention it it could happen to me, but hopefully someone can give some real world examples and situations.

On with the topic:
I am really struggling with how so many accidents possibly occur due to disorientation and vertigo. Even student pilots are trained to "trust the instruments" and don't rely on your body. I've been caught in temporarily questionable meteorological situations, had a quick out, but even at that point, I relied more so on my instruments than visual references. Is this something that when encountered in the situation pilots panic and forget to keep cool? I am really struggling to understand how a trained pilot can just lose control and plummet. JFK, Jr. is a good example. Are they simply not watching their instruments? Panic? Think all of the instruments are wrong? What about autopilot? Setting that is a good insurance against a slow deadly descent. I just had an accident near my house that was VMC into IMC at night... and that pilot was in fact instrument rated, and still plummeted. What am I missing here, and how can we all avoid these situations?

Thanks!
 
There is two issues here. If you have dyslexia or some other physical affliction which affects your ability to interpret and react to your instruments correctly, you shouldn't be flying in IMC period. Barring that, it's all about training and currency.
 
Go find one of the old AF spinny chairs and someone that knows the drill. Perhaps a decent office chair would suffice. You'll have no doubts about how easy it is to get vertigoed. For you, me, us, them...
 
If you are going to launch into IMC conditions you need to mentally note that the head stays down and focused on the panel.
 
@Greg: I'm not denying that I've ever felt it... I have a number of times. I'm just questioning how someone can get into the situation where they are trusting their bodies over the instruments... unless they're either not paying attention or are so distracted by the loss of visual reference and are so disoriented that they completely panic. Maybe they feel their body feelings are superior to every other pilot?

I'm hoping that someone can chime in with a better and more plausible reasoning.
 
A better pilot then us just prematurely unlocked the feathering system and blew up his spaceship. Threw one lever early. Anyone of us can do really retarded things while flying. We are monkeys not birds.
 
The body is heavily dependent on a fixed visual frame of reference for spatial orientation. Remove that and it becomes difficult to tell which way is up and which way is down. You can't interpret turns and aircraft orientation by feel - your body interprets seat forces as gravity.

So you have to block out the sensation of gravity and focus on interpreting your instruments. If you can't, you're dead.
 
ahkahn said:
[snip]

I just had an accident near my house that was VMC into IMC at night... and that pilot was in fact instrument rated, and still plummeted. What am I missing here, and how can we all avoid these situations?

Thanks!
Click to expand...

Welcome to POA.

I think what you're missing is that you should never underestimate the ability of your body, senses, and brain, to completely fool you. I imagine that many of these spacial disorientation issues begin with the pilot being surprised by a condition and then struggling to get ahead of the airplane and push away the overwhelming feedback of their senses.

The way you posed the question has a tinge of invulnerability attitude to it. I hedge against that by beginning with an understanding that these things absolutely could happen to me (because they've happened to scores of much better pilots than I'll ever be), and then asking those with more experience about the most common pitfalls.

I'll let those with more experience comment further. I am a low-time, non-instrument, fair-weather flyer.
 
The challenge is for your brain to decide between two conflicting inputs: your inner ear vs. your instruments.
As long as all is going along well, it's easy: the two inputs are mostly in agreement, so you keep on chugging.
The problem arises when you are under stress, perhaps tired after a long day, with perhaps some medications in your system, all of which causing your brain to not operate at its peak form. Fast head motion is also known to aggravate things.
When slightly handicapped and presented with conflicting inputs, with perhaps a bit of panic, the brain resorts to the most ancient and primitive input it trusts: the inner ear. Since the latter can be completely "tumbled", you end up in a spiral or other loss of control, which only gets worse as the inner ear's sensations are further aggravated.
The way to counter the above scenario is by not putting the brain in that situation in the first place: don't fly when stressed or tired, don't take drugs/meds, don't make sudden head motions, and force yourself to stay calm and collected, even when things seem to go haywire.
If you follow these rules and stay current, healthy and proficient, you won't ever lose control, or even come close to it. (And having a good autopilot while flying single pilot IFR can't hurt.)
 
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Hi Asechrest,

I certainly don't want to have an attitude of invulnerability, which is why I'm a truly trying to understand how this can happen. I totally get that the body plays tricks on you... I have about 10 hours of actual time, and know exactly what it feels like. I think the real issue here is that an attitude of invulnerability is based on ignorance and I am acknowledging ignorance and am trying to figure out what I don't know. Could it be that when these pilots venture into IMC they're in personal denial that they're in it? Most of the time they don't even radio that there is a problem.
 
ahkahn said:
Is this something that when encountered in the situation pilots panic and forget to keep cool? I am really struggling to understand how a trained pilot can just lose control and plummet. JFK, Jr. is a good example.
Click to expand...

I don't think it's panic. Note that fatal disorientation happened to captains flying airliners. I remember Quatar Airlines Airbus going into ocean like that some time around 2001. A TatarstanAirlines 737 went vertically nose-in late last year due to pure disorientation due to a go-around thrust.

When vertigo happened to me, I had to tighten up the scan significantly, because every time I looked at the charts for 5 seconds, the airplane started flying with 30 degrees bank.

Since a high mental discipline is necessary, a task load can make vertigo dangerous. In Tatarstan's case, the actions necessary to reconfigure the jet for go-around made the captain relax the scan enough to get things out of hand. I think that's where the greatest danger lurks: once you have to do something else besides watching the attitude instruments like a hawk, things go bad.
 
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ahkahn said:
Hi Asechrest,

I certainly don't want to have an attitude of invulnerability, which is why I'm a truly trying to understand how this can happen. I totally get that the body plays tricks on you... I have about 10 hours of actual time, and know exactly what it feels like. I think the real issue here is that an attitude of invulnerability is based on ignorance and I am acknowledging ignorance and am trying to figure out what I don't know. Could it be that when these pilots venture into IMC they're in personal denial that they're in it? Most of the time they don't even radio that there is a problem.
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Glad to see you here! Folks here have forgotten more than I'll ever know about flying, so it's a good resource.

My only experience with "instrument-like" flight is under the hood during PPL training. I did great under the hood. Except for my first time, which was about my third flight. I think that's way too early to put a PPL student under the hood, but that's how my instructor was. And I still remember how easily the plane got away from me, even though I knew what was going to happen and was able to get ready for it to happen.

I imagine that some of these spacial disorientation events involve an element of surprise and of concurrent or subsequent high workload, neither of which enhances your ability to push away what your body is screaming at you.
 
Thanks, Pete and Acecrest.

Makes sense as to why an autopilot is such a great tool in a situation like that. Many people seem to think that autopilots are for "lazy folk" but in that type of situation they truly do seem to reduce the workload immensely and increase safety.
 
ahkahn said:
@Greg: I'm not denying that I've ever felt it... I have a number of times. I'm just questioning how someone can get into the situation where they are trusting their bodies over the instruments... unless they're either not paying attention or are so distracted by the loss of visual reference and are so disoriented that they completely panic. Maybe they feel their body feelings are superior to every other pilot?

I'm hoping that someone can chime in with a better and more plausible reasoning.
Click to expand...

It's not just a simple matter of trusting your instruments. If that was the case, we'd hardly ever have any spatial disorientation accidents. Pilots trust their instruments, when they are disoriented, they don't understand what their instruments are telling them. We're not talking the leans here either. We're talking total incapacitation.

I'll tell ya about the time it happened to me and how I overcame it. I was a student flying the mighty TH-67 in Army flight school conducting an IAP while IMC. We were descending and turning inbound on the VOR approach into EUF. In the middle of the PT my IP directed my attention up and left to the overhead panel. I don't even remember what he said. Just mumbled something about a switch position. Anyway, when I looked back at my instrument panel, my whole world was spinning (corriolis illusion). I don't know if I fell back on my training of "delay intuitive reactions" but that's what I did. I relaxed my grip on the collective and cyclic, and just kinda let the aircraft do its thing. I experienced maybe 30-45 secs of complete disorientation and I knew my instruments were accurate but I couldn't comprehend what they were indicating. I stared at my attitude indicator and kept telling myself that blue was up. I was so confused that I had to ask myself "do I want blue to be up?" Scary. I found myself not scanning, interpreting and moving the controls but instead, I was rapidly going from once instrument to another and not getting any real benefit out of it. I suppose that could be panic. Finally, I slowed my scan, talked myself through what each instrument was telling me and regriped the flight controls. I was lucky in that 1) I was flying a two place aircraft and 2) I wasn't low to the ground were immediate action would have been necessary.

So that's how pilots can get themselves in a world of hurt real fast. In the debrief I found that my IP intentionally distracted me to see if it induced disorientation and how I would react. It worked. If I hadn't been a student I probably would have transferred the controls instead of riding it out like I did. I was worried about it affecting my grade. :(
 
Time and experience will enlighten you.

One experience that will do it for you is the failing, vacuum powered AI. It's an experience that can take you to the edge of mind/body conflict but you may never get to experience it in the age of the glass panel.

I'm guessing that you may have never experienced vertigo. It's easy to avoid in the modern world. The 'spin chair' can give you that experience and for those that haven't been there, it's a learning experience.

Keep flying, you'll get it. BTW, panic doesn't create SD and V, it's the result of it.
 
The traditional way to induce it is big head movements during steep turns. Rotordude mentioned a switch on the overhead console. Classic. Another good one is the fuel selector on a Cessna, or fiddling with the dome light at night. Any way you get your head moving orthogonal to the turn will trigger the Coriolis illusion.
 
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Bill Watson said:
Time and experience will enlighten you.



One experience that will do it for you is the failing, vacuum powered AI. It's an experience that can take you to the edge of mind/body conflict but you may never get to experience it in the age of the glass panel.



I'm guessing that you may have never experienced vertigo. It's easy to avoid in the modern world. The 'spin chair' can give you that experience and for those that haven't been there, it's a learning experience.



Keep flying, you'll get it. BTW, panic doesn't create SD and V, it's the result of it.
Click to expand...


I have ridden the Barany chair a couple of times and it is quite an education. Some FSDOs have them (or at least did) for Wings Programs. See if you can ride one.

http://en.m.wikipedia.org/wiki/Bárány_chair
 
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I think most of this has been said, and I'm no expert, but my take on it is: you're right, someone who is just out of their PPL training and still has drilled into them "clouds will kill me, if I can't see out the window, trust the instruments" is probably at low risk. Similarly, an IR rated pilot on an IR flight plan is probably at low risk. I suspect the ways this falls down are:

1. The VFR pilots (with or without IR, but who don't fly IFR much) who are very used to flying the horizon, have got themselves out of jams many times flying by the seat of their pants. They generally stay out of the clouds but are pushing their personal minimums, but go a bit too far and lose their reference. They don't have the "oh ****, time to trust my instruments" response because it's not a sudden thing, it's a gradual thing. They're struggling in their 3/4 mile visibility to see things that aren't there, but don't have the realization of "I can't do this VFR anymore". A bit of a lean, an imagined horizon, and they crash.

2. The IFR pilots who more or less know the drill, but get a case of vertigo that's so bad they physically freeze up or otherwise can't focus on their instruments. Especially if they never really had the cold-sweat/stomach-churning feeling in their IFR training, the first time they get it without a co-pilot or the ability to take off the hood can be really debilitating. Most will have the tenacity to stare down the instruments and make it work out, and/or the wisdom to ask ATC for a straight-ahead vector while they recover their wits, but some won't.

3. IFR pilots, especially single-pilot, who mess up on the switch back and forth between instruments and visual. The IFR go-around is a good example. If you are used to "flying the missed" as a purely under-the-hood maneuver, it can be disorienting the first time you switch to visual, then realize you have to go around, add power, clean up a bit, follow the runway visually, and suddenly you're back in the soup again without making a conscious decision go to "back on instruments." It doesn't help that this is also while the plane is in all kinds of accelerated modes (high AoA, banked, low-speed/high-power) and close to the ground already.

4. Legitimate instrument failures, followed by failure of a pilot to cross-check. (I include being vectored into a mountain here.) Let's be honest, most unexpected IFR situations could be handled by staring directly at the attitude indicator, keeping blue up, asking ATC for vectors, and making altitude and heading changes slowly and deliberately. Even if all you have are your three hours of PPL hood time, I think most pilots could handle this. But if an instrument fails, and you're not used to thinking about that, it's the same as an engine failing in a twin -- too much to figure out on the fly if it's not rehearsed.
 
Everything that's been said above, and one more, perhaps the most important factor: not realizing that one is in instrument conditions. Visibility can deteriorate gradually, one can still see a few features, or lights on the ground, and thinks that one has enough visual reference to control the airplane. Or is looking for the airport and keeps head up while visual reference gradually or unexpectedly disappears.

Even if the transition is sudden, it can catch you off guard if you haven't already established your instrument scan. Departing into a low (<1000 ft) ceiling, I was taught to go on the gauges as soon as clear of obstacles. A couple of times when solo I've interrupted my scan at that point to make a mental note of the bases and also the altitude at which the ground was no longer visible, and have found it distracting enough that I now resist the temptation.
 
Sac Arrow said:
If you have dyslexia or some other physical affliction which affects your ability to interpret and react to your instruments correctly, you shouldn't be flying in IMC period.
Click to expand...

The FAA appears to disagree with you, despite their policy of erring on the side of caution regarding medical concerns.

Dyslexia is not listed as a disqualifying condition for any level of FAA medical certification.

The FAA's Guide for Medical Examiners does not even mention dyslexia:
http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/media/guide.pdf

The FAA's medical-exam questionnaire does not even mention dyslexia:
https://medxpress.faa.gov/medxpress/Guides/MedXPressUsersGuide.pdf

The FAA's Pilot Handbook's chapter on Aeromedical Factors does not even mention dyslexia:
http://www.faa.gov/regulations_poli...on/pilot_handbook/media/PHAK - Chapter 16.pdf
 
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Very interesting discussion. What it sounds like is that the transition from visual to instrument can be a very disorienting transition, as well as or in conjunction with trying to stretch out the visual reference flying beyond it's useful utility.

Again, it sounds like a safe first step when feeling disoriented is engaging the autopilot (if equipped) while you pull your stuff together.
 
And if the autopilot doesn't engage you are a few more head swirls down the toilet.
 
So Greg, what's your advice on staying safe in IMC conditions?
 
From what I can figure going to 'instrument pilot' mode early is the safest thing. Don't stay vfr in mvfr and don't try and fly hybrid part visual part instrument.
 
ahkahn said:
What it sounds like is that the transition from visual to instrument can be a very disorienting transition, as well as or in conjunction with trying to stretch out the visual reference flying beyond it's useful utility.
Click to expand...

Yes, I think that's fair to say. Most of my instrument work has involved fairly explicit breaking in and out of clouds, but multiple instructors have advised me to keep "instrument flying" until at least a couple hundred feet below the clouds if possible given MDAs so that you're not trying to fly visually as you're in and out. (With all the usual caveats about watching for VFR traffic in the pattern if bases are at 1200', etc.)

Also why (as I understand it; this is well beyond my personal knowledge so correct me if I'm wrong) two-pilot crews will have one pilot looking for the field / flying the visual portion of the approach while the other remains on instruments throughout an approach. If the eyes-out pilot gets disoriented or you wind up suddenly back in a cloud, the eyes-in pilot should spot it and correct it right away.
 
azure said:
Departing into a low (<1000 ft) ceiling, I was taught to go on the gauges as soon as clear of obstacles. A couple of times when solo I've interrupted my scan at that point to make a mental note of the bases and also the altitude at which the ground was no longer visible, and have found it distracting enough that I now resist the temptation.
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I've always found departures into low ceilings to be most challenging 'normal IFR operation' from a SD standpoint.
ClimbnSink said:
And if the autopilot doesn't engage you are a few more head swirls down the toilet.
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Amen. Imagine if the AP immediately makes a correction that generates some g force and turning force that just further mixes up your inner ear. Do you turn it off or do sit there with your head and stomach upside down? Power?
ahkahn said:
So Greg, what's your advice on staying safe in IMC conditions?
Click to expand...
Get rated, stay proficient and fly behind a well maintained panel that you fully understand. Otherwise avoid IMC-like conditions like the plague. But that's not the answer you are looking for.

There was a great study done maybe 10 years ago where they did a simulated (pre-glass panel) instrument failure in several different light plane simulators (or perhaps the real aircraft). I searched but can't find it - worth a read.

One thing to remember is that the task of getting on instruments might start with the need to recover from an unusual attitude (think steep diving turn). SD, V, panic and the need to perform the right actions can all be compressed into seconds. That study confirmed that some rated pilots, in slicker aircraft, are not up to that very challenging task.
 
Practice! Practice! Practice! Your senses are very powerful -- don't underestimate their ability to override your rational brain (see Sexual Attraction).

When I was just about ready for my IR check ride -- full of self-confidence-- my CFII had the tower turn up the rabbit while I was landing under the hood. Worst vertigo ever; taught me to ignore my senses. :hairraise:
 
I experienced vertigo momentarily on a recent flight out of Galveston, TX. I launch into about a 500 ft overcast. I climbed to the altitude in the DP and then began my turn just as I was entering the clouds. For a split second I was disoriented and things didn't 'feel' right. I was knew I was turning but, once in the clouds, there was zero visual clue out the window or in the seat of my pants to indicate a turn. So my brain registered 'straight-n-level' suddenly. It was bizarre. My training kicked in quickly and I looked down at the intstruments, did a scan. Now my brain kicked into "instrument" mode (not sure what else to call it) where it - I guess - imagines the airplane turning and visualizes my position and all is right with the world.

Normally I transition to instruments several seconds before entering a cloud. It is less disorienting that way. But this time I didn't do that and it produced just a touch of disorientation.

But yeah that entry into and exit from actual instrument conditions can throw you. At that moment you can follow two paths: the seat of your pants path or the trust-the-instruments path.

If you have not been practicing the instruments you just might overreact and follow the seat of the pants/confused brain into oblivion.

I think practice and currency are keys to preventing this. That's why it's 66HITS and not 2424HITS. :D
 
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Don't fly into a cloud unless you have trained for it. Hood time with an instructor. Fly with an instructor in actual. No substitute.
 
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This was brought up not long ago and here was my reply. I read an article two or three years ago in a flying magazine about navy pilots having vertigo problems when flying off carriers at night. ( several fatalities) so, the ones with problems were sent back to patuxent for special remedial training. When one considers the training a navy pilot gets to begin with, which is way past what the average GA pilot gets, it's very understandable that this could happen to the average GA pilot. The 8 or so pilots I know that retired from flying as acareer flew instruments every week or more. The few I knew that did not fly instruments often, died as a result.
 
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I am severely dyslexic...and there was a comment about you should not fly instruments early in this thread...what a bunch of crap...I became a test case for the Aero Med lab at Ft Rucker while trying to develop a HUD system for the long gone and never produced Comanche...green red yellow on gages and an attitude indicator are no issue... 20 year career as an MTP...I cant spell worth a damn and might transpose numbers on a check but never had an issue in the clouds.
 
ahkahn said:
Hi all,

I've been a lurker for quite some time, and love to take it all in. I'm at the 200 hour mark and a few days shy of my instrument checkride. I'm really struggling to understand one concept, and I purposely posted this in the general forum because I believe the information is pertinent to ALL pilots, IR, PP, or student. Murphy is telling me not to bring this up, because as soon as I mention it it could happen to me, but hopefully someone can give some real world examples and situations.

On with the topic:
I am really struggling with how so many accidents possibly occur due to disorientation and vertigo. Even student pilots are trained to "trust the instruments" and don't rely on your body. I've been caught in temporarily questionable meteorological situations, had a quick out, but even at that point, I relied more so on my instruments than visual references. Is this something that when encountered in the situation pilots panic and forget to keep cool? I am really struggling to understand how a trained pilot can just lose control and plummet. JFK, Jr. is a good example. Are they simply not watching their instruments? Panic? Think all of the instruments are wrong? What about autopilot? Setting that is a good insurance against a slow deadly descent. I just had an accident near my house that was VMC into IMC at night... and that pilot was in fact instrument rated, and still plummeted. What am I missing here, and how can we all avoid these situations?

Thanks!
Click to expand...

What everyone is missing is THE CHAIN.

The folks you never hear about broke the chain...and diverted or made good choices.

The crashes from many NTSB reports....time and time again had an opportunity(many times more than once) to break that chain and didnt.

Keep adding links to the chain...your chance of death greatly increases.

Hindsight gives a clear picture of the chain....those that have foresight never get past a link or two....maybe get puckered but live to tell the tale.
 
So, you as a VFR-only pilot stumble into a cloud on a night cross country. What do you do? Go into instrument mode, establish a scan, click on the A/P.

Hmm, 2 minutes later the cloud is still pulsating with your strobes, oh that's right, let me turn them off. Yes, better. Two more minutes later, what's going on?

Did you contact ATC yet and ask for help? Declare an emergency? No? When? Why? Why not?

What do you think your best plan of action is? Descend? 180? Soldier on?

Yep, chain theory is BS but suddenly it seems like it's all just held together with a string....
 
TEFLONSEAN said:
Actually quite factual....you should educate yourself.

But your opinion is noted. Thanks.
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Chain theory is Monday morning quarterbacking mixed with fan fiction and literary criticism. Nonsense.
 
I read a article where an ATP rated helicopter pilot when IIMC, got into a very radical attitude, body didn't jive with his attitude indicator...so he caged it :yikes:

Didn't end well.
 
TEFLONSEAN said:
What everyone is missing is THE CHAIN.

The folks you never hear about broke the chain...and diverted or made good choices.

The crashes from many NTSB reports....time and time again had an opportunity(many times more than once) to break that chain and didnt.

Keep adding links to the chain...your chance of death greatly increases.

Hindsight gives a clear picture of the chain....those that have foresight never get past a link or two....maybe get puckered but live to tell the tale.
Click to expand...

Great point.
 
Sobering thread. Gives me yet more respect for the folks who fly all the time.
 
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