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Inadvertent IMC - What to do if it happens?

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Inadvertent IMC - What to do if it happens?

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Old 22nd Jun 2005, 04:09
  #21 (permalink)  
 
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Hey Chops.

First up good stuff for throwing it out there so you can increase your knowledge about this topic.

I offer the following:

Your initial post starts with the heading that states IFR question and then describes "guys if you are a vfr pilot and happen to find yourself in imc conditions"

This really is the start and finish point to your question. As others have already stated you can't be in IFR (Limited VMC conditions) with a VFR mindset and VFR/GF training.

VFR and IFR are two very different types of operations and ACFT and crews are set up accordingly whether you are FW or RW. How do you avoid being in marginal VMC/IMC?

Answer-It all starts at the pre-flight planning stage. WX, Notams, Certification of ACFT, profficiency, experience, ratings, Rules and regs, Fuel, LSALT etc all need to be applied to the situation BEFOREyou launch. This will mean some of the time you as the PIC will need to knock back the tasks that will place you and your ACFT in these situations. Folks will not want to hear that they can't proceed on their planned flight or the mission is cancelled due wx, however that is why you are a PROFESSIONAL AVIATOR, and are paid the big bucks for your COMD Decisions.


A large proportion of accidents/incidents both military and civil result from penetration from VMC into limited VMC/IMC conditions. The folks that become accidents in these situations are the ones with little to no instrument flying training or rating, the ones that are recorded as incidents are either lucky or have the required instrument skills and rating and are able to conduct an IIMC recovery and recover via an instrument app or Radar vector to cloud break etc. Again planning is the key.

You should avoid seeking a formula (recipe type answer) to your question as each situation is different. Take stock of what the pros are telling you and rewind the situation back to the pre-flight planning and pre-launch stage.

If you don't already have an Inst Rating you should consider going and getting one as this will inevitably add to your bag of tricks and will make you more employable in the long run and give you some excellent skills which you may one day need.

Avoid the Recipe/Formula response. If you fail to plan, you are planning to fail.

IMHO

Give It Some



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Old 22nd Jun 2005, 05:21
  #22 (permalink)  
 
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Back to the question: What IF, regardless of how you got there (the trouble with teaching some people "a little bit of IF" is that they think they have to use it).

This actually happend to two friends of mine, one an experienced ag pilot trying to get back to the South across Inkpen Ridge (in Hampshire, for those who haven't been to Wallop) and the other was in N Ireland chasing terrorists in 'orrible weather, somewhere near Omagh, both in Bell 47s, and the first one without the instrument pack, so it doesn't just happen to inexperienced pilots. A moment's inattention will do it. The one in N Ireland just climbed up and got Aldergrove ATC to position him over Lough Neagh, where he descended through it, and the one at inkpen ridge went into autorotation and came out of it backwards.

I think the key to this problem is to descend, since gravity will help keep the wings level. Without any IR experience, I certainly wouldn't try anything more than the gentlest of turns, and the only reason I would do that would be to get closer to the last known wind direction.

I'm with rotorspeed, in that most machines would allow some survivability in the event of crash (sorry, positive landing), especially a Bell 206. If I remember rightly, the rotorway exec is rigged to go to a 45 knot attitude automatically if the engine quits.

If I got away with it I would make a mental note to buy my guardian angel a crate of beer. The N Ireland guy certainly will - his engine quit about 30 seconds after landing through lack of fuel.

Phil
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Old 22nd Jun 2005, 06:45
  #23 (permalink)  
 
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Choppersquad knows he shouldn't get himself into such a dangerous situation. All he's asked is what he should do if he finds himself in an emegency situation "due to whatever stupid circumstances" he's put himself there.
Of course people shouldn't, but the sad fact is they do.

It may be that any advice (however good) is academic because he's likely to lose control in seconds rather than minutes and die anyway, but all he's asking is what he should try to do while he still has control.
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Old 22nd Jun 2005, 07:11
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Interested by this advice to reduce speed. If you get on the wrong side of the power curve, your speed becomes unstable there by increasing work load.

My advice - as soon as you start to see whispy bits around you, dump the lever before you loose sight of the ground, find a field, land. If it has a pub in the corner, so much the better. If you go IMC get your eyes moving around the instrument panel like your life depended on it.
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Old 22nd Jun 2005, 08:45
  #25 (permalink)  
 
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Exclamation

Choppersquad,

What to do if you inadvertently enter IMC is not something which can be answered by a simple formula, like 2+2 = ? It would depend on the circumstances and it's worthe listening to the advice of the other posters here. The main thing is - 'Do not panic!'. Much easier said than done I know. Secondly, take a split second to think of what you believe to be in your vicinity before acting. Sometimes it may be better to descend slowly ahead (but you can't do that if there's something large and hard ahead of you!) and sometimes it may be better to turn (but you can't do that if you're in a narrow valley or have other obstructions to your side or that you've just flown past, now behind you). I'll illustrate what I mean and why it's a VERY BAD thing to become inadvertent IMC by citing an example of what happened on an offshore contract, with an instrument rated pilot, in an IFR machine many years ago:

A moderately experienced pilot offshore was flying single pilot VFR in an IFR equipped (SAS and full instruments) Bell 212. It was a nice, clear morning, but with quite a few fog patches around. He was making an approach to a large production platform (rising to several hundred feet above the sea) when he entered a fog patch. He thought he would come out of the other side before he got to the platform, which he had on his weather radar. Even though in fog, he could occasionally glimpse the sea surface below him. When he got to less than a mile from the platform he was still in fog and wisely decided to make a 180 turn as there were no other obstacles. He had already reduced his airspeed, but instead of remaining on instruments, he tried to get a visual reference in the turn and, his instrument scan now broken, he became disorientated. His airspeed reduced to less than 20 knots, angle of bank was too high and he rapidly descended. With insufficient power left to him to recover at his airspeed, he flew into the sea.

So, take in all the advice given to you here, but try to never, ever have to use it.
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Old 22nd Jun 2005, 08:53
  #26 (permalink)  

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"er, SALT please somebody. I can imagine it may be.....??"

Safety ALTitude. Military term, more or less the same MSA.
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Old 22nd Jun 2005, 09:22
  #27 (permalink)  
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thank you guys
i feel all posts are worth reading.
however heliport has made my point again.i know it is not a simple answer but sometimes old school looks at pilots as if it has never happened to them or never will .as we know atpl cpl
pilots make a lot of silly mistakes and some pay the worst price of all .a ppl with 20 hours knows he should not fly into imc .but he may at somtime of his life.he knows not to fly into the wires etc etc, my point is when all comes do all and your in it what do you do ,thats what i was looking for from the posts .please do not scare future pilots off by answering the question in such a way that it was silly to be there in the first place or low time pilots will never post a question.

thanks guys
choppersquad
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Old 22nd Jun 2005, 09:30
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Inadvertent IMC

The best advice I could offer is to do some basic instrument flying then at least if you go IMC you will be able to keep the thing straight and level.

If you go into solid cloud climb to a safe altitude and call ATC with a PAN. They will do all the thinking for you and you on concencentrate on staying slippery side down.

It does take a lot of concentration to instrument fly in an unstable aircraft.

Carrying out a controlled descent is all very well if you know the cloud base and turning back is good advice as long as you know the reverse course is clear. But do not carry out a panicky 30 degree bank or you will become disorientated and end up crashing.

The moral of the story is to be aware at all times of the terrain you are flying over.
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Old 22nd Jun 2005, 09:30
  #29 (permalink)  
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Thanks ST


I've gone in the soup before while careful scud running. I knew exactly what was behind me, so I stayed perfectly calm, lowered the lever slightly to ENSURE I came out of it, and made a very gentle backtracking starboard turn until I saw the ground again. Very sensible advice. The cloudbase was at least 1000' or I woudn't have been up there. This was a H300 which I believe to a good stable machine which is quite difficult to get into unusual attitudes with a bit of speed on. The machine in question had everything to get you out of trouble though including an HSI, so may have cheated a little in that respect. See, if you've got it, you will be tempted to use it !

( Chopersquad - don't let them bully you - i've got used to it now - if you've got a burning question, ask it ! It could get you out of trouble one day. They pretend to be big and bad and burly, but they're all pusscats underneath ! )

Last edited by TheFlyingSquirrel; 22nd Jun 2005 at 09:44.
 
Old 22nd Jun 2005, 09:37
  #30 (permalink)  
 
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FS...
SALT please somebody
As already stated, this is the Safety Altitude. If you look on a half mill chart, you will see blue numbers all over the chart, a large figure and a small figure(so 39 is 3900ft). This is the altitude of the highest known obstacle(terrain and objects) in that area. To calculate the SALT(in the military, I assume it's the same for civilians), you add 1000ft and then round up to the nearest 100ft.
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Old 22nd Jun 2005, 09:50
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'If you look on a half mill chart, you will see blue numbers all over the chart, a large figure and a small figure(so 39 is 3900ft). This is the altitude of the highest known obstacle(terrain and objects) in that area. To calculate the SALT(in the military, I assume it's the same for civilians), you add 1000ft and then round up to the nearest 100ft.'

[b}Sounds great if you fly and live in the UK for other countries (yes there's more than one) consult your own countries military or civil procedures.[/b],

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Old 22nd Jun 2005, 11:20
  #32 (permalink)  

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Good thread. Good question, and I'm glad someone asked it. Of course going inadvertantly into cloud shouldn't happen, but it can. It happened to me flying a f/w aircraft, which is much more stable, so it wasn't so bad. I thought I was flying into haze which I could see through, then realised it was cloud which I couldn't. I was able to descend gently, knowing I'd come out of it before I reached the ground.

As several people have said, what you do may depend on the situation. But if at all possible, I'd descend gently, avoid turns, and definitely avoid anything else like talking on the radio. With a PPL(H), and only 5 hours instrument training, probably a long time ago, that will take 110% concentration anyway. And concentrating on breathing deeply will help to prevent panic.

One thing I'm surprised that no-one has mentioned is "the leans". If you're really in cloud with no visual references, you are very likely to feel that you're in a turn when you're not. For me, this happens particularly in the R22, for some reason. So TRUST YOUR INSTRUMENTS COMPLETELY!!!! It may be hard, but you have to do it. They are the only thing which might get you out of this situation alive.
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Old 22nd Jun 2005, 11:28
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God - he asked a simple question and most have complicated it beyond description.
lets go back to school, pretend you're all in an exam and you have just turned the first page over.....

Read the Question

"...I am now in IMC and want to know what to do next..."

Choppersquad, this is what will happen for real, OK:

You will imediately depart from stable flight.

Either you will correct for it and maintain some sort of 'controlled' flight, upon which you MUST IMMEDIATELY consider the following (now you have bought time)(this is assuming it's happened in the UK)
(a) DO NOT do a 180 unless you can guarantee return to VMC within seconds. This will further exacerbate any leans or spatial disorientation feelings you are fighting off.
(b) DO NOT, repeat DO NOT, fly below 60kts indicated airspeed. Low speed flight in IMC is the quickest way to losing controlled flight by a non IR pilot.
(c) DO NOT descend in IMC unless you know the cloud base is well above the local terrain (1000'+)
(d) Try to change momentum in 1 dimension only: climb or speed up, or turn. Don't mix them.
(d) CLIMB to a height which you think is above the nearest high ground. Do this at around 60-70kts airspeed and max continuous power.
(e) Level off and then, only then, after you have calmed down, talk to anyone! (Ideally an ATC nearby). They will do their best to help you out of it.

All of the above is based on YOU being able to keep the machine relatively stable.

IN THE EVENT YOU CAN'T MAINTAIN HEIGHT/HDG AND SPEED:
The a/c will almost immediately begin a descending turn, the speed will increase to a deafening rush, the ball will depart way out left or right, you will overtorque, the Nr will decay and the ROD will probe new depths. The end will be very very quick.
The time has come for you to leave this world, my friend. Say your goodbyes. make some final transmissions to assist the AAIB / ATC / rescuers / friends and family....RELAX
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Old 22nd Jun 2005, 15:06
  #34 (permalink)  
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Well it seems everyone has got their own get out clause on this one - I just believe most pilots know what they can handle and for how long - the old perception of abilities corner - the best advice seems to be what ever you can do to safely get out of it, do it, but overall stay calm and remember the old ANC acronym, Aviate, Navigate and if you've got a spare brain cell available, Communicate ! It hurts more head on then butt down !

TFS
 
Old 22nd Jun 2005, 15:44
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Great, thats answered his question then?

Ironically the latest Gasco flight safety colour mag (Vol 41, No2) has an article on this very issue!!!
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Old 22nd Jun 2005, 16:04
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Sorry to swing your superiority hammock TC - just relaying some FW experience too.
 
Old 22nd Jun 2005, 17:14
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Sorry for joining this post late, but wanted to add something.

Want to find out what will happen when you go IMC without knowing 'What to do next'? Purchase a PC based simulator, doesn't matter which, X-Plane and MSFS do helicopters and aircraft, ELITE does aircraft only.

Takeoff, get a feel for the aircraft, then set the weather to IMC. You'll quickly get an idea of your capability to survive in IMC. If you can climb, pull out a chart and shoot an approach to the nearest airport you certainly have a better probability of surviving than if you struggle to keep it upright.

Now before we bash PC based simulators, I used MSFS and its Jetranger to practice for my IFR training and by flying it a way too many hours, I got to the point where I could do whole flights IFR/IMC, partial panel. When I stepped into the real aircraft and put the hood on, the hours I spent sitting on the computer paid off. While discussing the differences in Simulator/Real are beyond the scope of this discussion, I can say I was well in tune to the control inputs and instrument responses required to fly the aircraft. Even now I still practice with the simulator. When I get to fly in actual it feels no different than the simulator to me and thus I am able to fly to a high standard.

That's my advice, learn to fly on instruments, even if it's just with a simulator. You won't survive on numbered 'to do' lists upon entering IMC.
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Old 22nd Jun 2005, 17:32
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Flight Simulator

He's right you know I used to practice instrument procedures on Flt Sim and it helped. If I was going to a new airfield I would get the airfield plates and practice the approaches at home.

Great bit of kit.
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Old 22nd Jun 2005, 17:53
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The best advice is don't go IMC in the first place, That said for my first few years as a CPL I had trouble recognising my limits (Viss & Cloud base) Im pleased to say as time went by it got easier now I simply don't go IMC (Never)

Don't let your self get boxed in by low cloud & low viss, Slow down, Full carb heat? or Anti ice? Always leave a way out. This can be done you just have to turn away in time. Dont wait till you can't see the ground.

Don't go VFR on top either, Its not legal, If you have a power failure you have to descend through it and it easier to get boxed in.

Someone mentioned inadvertant IMC at 1000 ft AGL, This is not so realistic. When people end up IMC its normerly about 500ft or lower above the deck.

I wouldn't advise lowering the lever and decending at this low height.

The 180° turn might work hopefully you won't bump into anything or loose control during the turn.

TCs advice is good slow down to 60 knots and climb, When you break cloud request assistance and get a radar talkdown. if the cloud tops are high you have a big problem.

Other problem's carb icing? Airframe Icing? Induction icing?

I had a good friend who went inadvertant IMC a few years back, He requested assistance. He ended up flying into a hill killing everyone onboard. He was VFR rated but had about 15 hours instrument flight training (It's no guarantee)

Best advice is do what ever it takes to avoid IMC in the first place.
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Old 22nd Jun 2005, 18:53
  #40 (permalink)  
 
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TC

The trouble with your advice to climb is that you are committing the pilot to a full blown IFR flight now. What exactly is going to be the advice from the helpful ATC? Assuming they soon realise an ILS is out of the question, I guess they will try to find somewhere with a 1000ft + cloudbase to let down over. How long will that take them to work out? Vector you towards some friendly mil field for effectively a PAR perhaps? Whatever, it's all going to take quite a lot of time. Time that our VFR pilot has got to try and maintain control in IMC. And turn, and climb, descend etc. How good were you at listening to the RT when you were on day one of your IR training? And then how much fuel has he got? Quite possibly not enough to get to the desired let-down area, for it would be reasonable to assume that if he has got himself into IMC, the cloudbase might be, what, 300 - 500 ft, say? Where our nice 1000ft ceiling is KNOWN to be is likely to be some way away. Could be 30 mins flying. With panic building.

It is reasonable to think that our pilot, stupid though he was to get himself into IMC, probably realised his situation within no more than a few seconds. More than 10 seconds? I doubt it. So the chances are the cloudbase has not changed to hugely in that time. So by lowering down in a straight line carefully he will probably be out of it within another 10 seconds; 30 seconds max.

To me, that's a got a less high risk of disaster than your solution.

Agree not less than 60 kts though!
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