Inadvertant IMC and crashing!!

[MightyGem]

I saw an article sometime ago in an aviation mag giving a countdown from going into cloud and crashing (took about 90secs) for a non-rated pilot. If anyone could post the text, I'd be grateful.
Thanks

[2Donkeys]

178 Seconds to Live

How long can a licensed VFR pilot who has little or no instrument training expect to live after he flies into bad weather and loses visual contact? In 1991 researchers at the University of Illinois did some tests and came up with some very interesting data. Twenty VFR pilot "guinea pigs" flew into simulated instrument weather, and all went into graveyard spirals or roller coasters. The outcome differed in only one respect - the time required until 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 5500 feet but your map tells you that there's local terrain as high as 3200 feet. There might be a tower nearby because you're not sure how far off course you are so you 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 feelings in your stomach that tell you're banked left, then right! 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've only referred to you instruments in the past and have never relied on them. You're sure that this is just a bad spot and you'll break out in a few minutes. The problem is that you don't have a few minutes left.

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 are confused so you assume the instruments must be too. You are now experiencing full blown Spatial Disorientation. Up feels like down and left feels like right. You feel like you are straight and level again but you're not. The spiral continues.


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 3000 feet. Instinctively, you pull back on the controls but the altimeter still unwinds. You don't realize that you are in a graveyard spiral and it only gets worse. Your plane is almost sideways you're just tightening the turn by pulling up but all you can see is that altimeter going lower, lower, lower. The engine is into the red and growling and the airspeed is dangerously high. The sound of the air passing by begins to resemble a scream.

You now 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. It's supposed to do the opposite! You can hear the wind tearing at the aircraft. Rivets are popping as the load on the wings and tail far exceeds design specifications. 1800, 1500, 1100 feet...... down you go.

You now have 10 seconds to live.

Suddenly you see the ground. The trees rush up at you. You can now 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. . . . . .

Your time is up!

[Vfrpilotpb]

TD,

I have gone through that post of yours twice,the only comment I can make is that it is so intense, you can almost feel it, you can put your mind into it, you can see the ground at that crazy angle!
Well put.
My local CFi on Helis, tells me 45 secs is the absolute time anyone has lasted in a heli! sure enough to keep me out of the grey stuff.

[Whirlybird]

Much much much much much harder in a heli, especially an R22. After nearly 15 hours instrument flying in them, all I know for certain is that I ain't never going near a cloud in one.

[Flyswift]

Wow..... scary stuff. Stay out of the mist...

[englishal]

the moral of this story is to get some instrument training! When I was doing training for my IR (FAA) one thing will always stick in my mind....the instructor told me to fly the aircraft as normal with my eyes shut....45 second later look out... until I opened my eyes everything FELT normal but when I opened my eyes I saw we were heading earthward in a very step left turn, very fast...So shutting your eyes is effectively like flying into cloud and not being able to interpret the instruments. Don't rely on 'staying out of the mist' as one day it may come back and bite.

[Evo7]

I was amazed at the effect a bit of cloud has. On my last lesson we flew into cloud - the first time I've done that - and within seconds I had managed to put us into a descent, albeit wings level. Second time I was confused enough to open the throttle rather than close it while trying to manoever. A good lesson there.... :eek:

[hoverbover]

Vfr and Whirly,

Next time you are with your friendly instructor, ask to go under the hood and do an approach to hover all under the hood. It will give you good practice and as you get close to the hover your scan will be right up to speed!!!!!!

It is possible with practice and gives you an even better appreciation of the demands of instrument flying in a heli, and the pitfalls of decaying airspeed.

You are quite right, stay out of the grey stuff, but it is nice to know what comes next!

Regards

HoverBover

[MightyGem]

2 Donks, many thanks for that.

[Vfrpilotpb]

Is this situation one of lack of trained knowledge, or is it a mental/health problem, I remember a test which we undertook at school, administered I seem to think by a military Doc, he had us stand as straight as we could, close our eyes and tilt our heads back slightly, some of us stood motionless and others wavered around like a tree in the wind,when they opened their eyes, the ones who had moved around were not aware of this movement, it was then explained to us that it was to do with the brains ability to sort out signals from the ear, without the benefit of a visual cross ref from the eye, so despite whatever amount of IMC training you undertake, will there always be some who just can't grip it well enough because of this medical possibility. :confused:

[Whirlybird]

vfr,

I'm not 100% sure what you're getting at, but in IMC you must ALWAYS trust your instruments. With no visual references, it is impossible to fly by the seat of your pants or any other senses. And I'm sure anyone can learn instrument flying; all it takes is practice.

[Final 3 Greens]

I've always thought that the hardest thing to do in IMC is to maintain situational awareness.

I'm not instrument rated, but I do make a point of undergoing regular instruction, so that if the worst happens, I can safely get out of the IMC encounter asap.

On the one occasion that I needed to do this, I found that I "knew" I could fly on the panel anad this allowed me to avoid panic and safely take the aircraft back out into VMC within half a minute.

However I would not have wished to press on in the cloud, since it took all my concentration to undertake a balanced 180 and maintain altitude!

[poetpilot]

Scary. It nearly happened to me once, flying a Jodel with a u/s AI, going to a business meeting with the added pressure of a pushy passenger on board ("we must get to that meeting on time...").

The really scary thing is the insidiousness of it as the situation creeps up on you. You just don't know it until it's too late.

I was skirting some clag, in sight of the ground but with limited forward viz, not realising just how limited forward it was.

I was also (fatal mistake) relying on an ATC report of VMC conditions in the area & an insistence by them that I report at a particular VRP(I know much better now).

In my scenario, knowing that I couldnt trust my head to tell me which way up I was, I immediately chopped the throttle and let go of everything. A most horrible feeling of utter helplessness, everything screaming at me to handle the controls.

Good old bird that she was, the Jodel didnt pick up too much speed and thank god we popped out of the clag in a level glide after what seemed an age but was probably less than 20 seconds. Had it been longer of course, even with no control inputs the aircraft would probably have started a diving turn of its own accord.

I count myself exceedingly lucky & certainly learned about flying from that. I do NOT recommend anything I did as a way out of such a situation - it was more luck than anything that I'm still around.

The business meeting? I diverted and cancelled it. Passenger didnt like it but tough - I just wanted to go home.

Oh yeah - forgot to mention also. I was IMC rated at the time. But when you look at the haphazard panel of a Jodel, especially with an AI spinning round and round, it's a completely different ball game to a nice, relatively ergonomic PA28. Limited panel just went out of my head at that horrible moment.

[ 05 November 2001: Message edited by: poetpilot ]

[Vfrpilotpb]

Whirly,
I missed of the part that would have made sense of my post, so sorry, but yes you are right , you must trust your instruments, for they dont know that you have flown into the grey stuff, but there are pilots who will ignore the instruments, because they feel that up, is down, and right is level and so on, could this possibly be caused by the medical/physical situation that I refer to, do their inner body feelings and sense's overcome the picture being shown on the dial's.
By the way, regarding the 45 seconds of life on the heli, the Cfi was referring to R22!

Had a go in a Squirral Sim not long ago, I found inst sim flying wrecked my confidence completly!

[Vortex what...ouch!]

I have done some instruments in the R22, hydraulic R44 and the Jetranger. It gets easier as you go up in size :) I have also been on a check flight in an A109 in full IMC.

Without doubt I would not like to have to rely on instruments in an R22, very very hard work. Hydraulics and stability reduce the workload by a factor of 10, that’s why they invented SAS’s :)

I have inadvertantly flown into cloud once in the R44 Raven while trying to climb on top. Over wales with scattered at about 5k I aimed for a large gap between clouds but misjudged the size of the cloud, which is very easy to do. It was a scarey experience for a second but I went instantly onto instruments and setup my scan. I didn’t panic and just flew the aircraft watching the instruments. I knew I would break into clear air any second, it turned out to be about 20 seconds. I certainly wouldn’t want to do it again though. I can see how the fear you first feel as it all goes white could take over and it’s just a matter of time then.

I have since spent some more time with the screens in and an instructor flying with sole reference to instruments so if it ever happens another time but perhaps in less favourable conditions I will be better prepared. The 5 hours you do for the PPL is clearly not enough, particularly in helicopters.

[Whirlybird]

Vortex What,

Last winter, with a CAA PPL(H), I decided to do a few hours in the R22 on instruments as a safety measure, in case I inadvertantly flew into cloud. Just over 4 flying hours later I knew there was no way I'd ever go near a cloud in the R22. I've just finished the 10 hours of instrument flying required for the CPL(H). I now feel a little more confident about it, but it's incredibly hard work in an R22, and I really wouldn't like to be doing it for real.

vfr,

Inaccurate perception in IMC is common and normal. In the absence of visual references, the body can interpret acceleration as turning for example. Remember the classic example which always turns up in PPL human performance exams - acceleration perceived as pitching up so if it happens during a go-around you can fly into the ground, and it's happened. People ignore the instruments and go with how they feel, because the illusion of turning or leaning (commonly known as "the leans") can be very real and very disorientating. I've had to steel myself to ignore my feelings when I feel as though I'm in a steep right hand turn although the instruments tell me I'm straight and level, and if the instructor then tells me to turn right...you can feel like you're hanging out of your seat!!! And if you're doing it for real you then have to navigate, talk on the radio, etc etc. That's why it's so difficult. Anyone who says it isn't hasn't tried it.

[John Farley]

Whirlybird
Inaccurate perception in IMC is common and normal. In the absence of visual references, the body can interpret acceleration as turning for example. Remember the classic example which always turns up in PPL human performance exams - acceleration perceived as pitching up so if it happens during a go-around you can fly into the ground, and it's happened. People ignore the instruments and go with how they feel, because the illusion of turning or leaning (commonly known as "the leans") can be very real and very disorientating. I've had to steel myself to ignore my feelings when I feel as though I'm in a steep right hand turn although the instruments tell me I'm straight and level, and if the instructor then tells me to turn right...you can feel like you're hanging out of your seat!!! And if you're doing it for real you then have to navigate, talk on the radio, etc etc. That's why it's so difficult. Anyone who says it isn't hasn't tried it.

May I offer my sincere congratulations on the best 166 word summary I have yet come across regarding the problems of instrument flying. They are both accurate and from the heart - two very important things when talking aviation. The next person to write a book on the subject would do well to ask your permission to quote them on the dustcover.

[Final 3 Greens]

Whirly

I know what you mean about the distraction of the "leans."

Funnily enough what helped me a lot was doing some instrument training in a flight sim with very gentle motion.

Once I had done a few hours, my mind seemed to relegate any feelings to "background noise" and my ability to concentrate on the instruments became much better.

Since then, I have done some flying in a PA28 "under the hood" and have found that my focus on the panel was maintained and the background awareness of motion much reduced in impact.

Presumably this is a psychological effect, but when I go back visual, the world is quite confusing for a few seconds, as sky, clouds and fields replace AI, HSI etc!

[JP5A]

Itis very important to not only trust your instruments but know how they are powered.Some instruments are vacuum driven such as DI/Hsi and AH whilst others are electric such as the turn and slip.It is quite common,however,to have an electric HSI.I had a quite stressful experience in our group rockwell commander 114 in IMC a couple of years ago.The AH failed but fortunately I was on top of the cloud cover at the time.I looked at the vaccuum gauge which indicated a pump failure with the dolls eye clearly visable (the engineers found later the vaccuum pump had sheared).
By understanding the instruments I knew that the HSI was still functioning and turn and slip O.K.also.Obviously ASI is not a gyro or altimeters and VSI.
The next step was to descend through approx 2000ft of cloud and get visual without getting disorientated and using ASI and VSI for pitch and turn & slip and HSI for direction i.e.keeping out of a spiral dive.I set the aircraft up in a 500 ft descent which would take 4 minutes approx to get visual.
Things worked out but if I had lost the AH whilst in solid clag I may have followed it if I had not noticed the vaccuum gauge.
All good fun eh??

[Code Blue]

Some excellent posts.

Don't forget about night VFR. One of my scariest nights as a 200h pilot was when the moon disappeared behind a solid overcast and the terrain had no lights (wilds of the unfrozen North). Whirly's description of 'abnormal sensations being normal' was certainly true! :eek: It's hard to know when you're in cloud under these conditions - it is really a form of IMC.

Interestingly, the reported fatalities for pilots continuing into IMC seems to be the same for instrument and non-instrument pilots in the NTSB reports. This may be a reporting error, but bears some thought.

Rgds
CB

[Julian]

Good synopsis by Whilry bird! I have just completed the IR(A) and the 'leans' is weird when it takes you over and you feel you want to correct the plane, only to look at the instruments to find if you had you would have completely misinterpreted what the aircraft was doing.

What brings it home even more is when you go partial panel, losing the AI and the DI. You have to fly on your magnetic compass and associated lead/lag as well as altimeter/ROC Indicator. The omprtance of standard rate timed turns comes into its own during this scenario.

Julian.