I'm lost! A Surivivors Guide. [Archive]

sennadog

21st Oct 2002, 09:38

Hersham Boy's thread regarding Lamberhurst got me thinking (it's an easy to miss place) about putting together a Survival Guide for getting slightly or completely lost.

On the assumption that you don't have GPS, as we've done that argument to death, and are using dead reckoning for navigation - what tips would you guys give to re-establish your position?

I'll start with a few ideas:

Check your position in relation to the sun. Sounds a bit daft but it does give you a bit of confidence in your own decision making abilities and obviously you can cross check it with your instruments.

Distinguishing features such as water, railway lines, motorways etc. Match it up with your chart to help determine your postion. Water such as a reservoir is always a favourite as you can see it from miles away.

I won't go into VORs etc yet but what I'm aiming for is a check list of ideas to help everyone.

Over to you.:D

ChiSau

21st Oct 2002, 09:43

Does "Training fix, training fix" on 121.5 count??!?!?
:D :D :D

sennadog

21st Oct 2002, 09:48

ChiSau - of course it does! It's just not the first thing that I'd try.

A training fix would come a little bit further down the list, that's all.
:D

ChiSau

21st Oct 2002, 10:05

Seriously though - its a good thread.

Having now got myself rather lost on a couple of occassions I can vouch for how scary it can be.

As you say, topographical features are incredibly helpful and one occassion sufficed. On the other hand, they're not much help if you're flying over somewhere pretty featureless. On that occassion I resorted to a VOR crosscut and a training fix call! :D

My instructor was kind enough to say that there are two types of people: those that have been lost and those that are going to get lost!

FlyingForFun

21st Oct 2002, 10:21

Most important thing is to make a log as you fly. Every time you make a positive fix, note it down. Maybe just a mark on your chart. And if you're ahead of or behind schedule, note the time you were overhead your fix. More on that later.

Next most important thing - once you realise you're uncertain of your position, note down the DI heading, the compass heading (if different), and the time. Once you've done that, you have two choices, and only two choices. Either continue flying in the same direction, or else stop, orbit, and note the time that you started to orbit. The best advice is probably to carry on for a while, but orbit before you go too much further. Unless you know you're going the wrong way, e.g. because you find your DI has wandered without you noticing.

Now, you've got all the information you need to figure out where you are. You know your last fix. You also know what direction you've been flying, and how long for. If your DI and compass didn't match, you might have to do a bit of guesswork here - were you slavishly following the DI the whole way? If so, you don't know exactly what point the DI started to wander, so you're a little less certain than you would be otherwise. But you've still got enough information to be able to draw an area on the chart which you know you must be in.

Now, find something obvious on the ground. Then try to locate it on the chart, within the area you think you're in. Nothing obvious on the ground? I think that's very unlikely! What about hills, ridges, rivers, roads, those three little villages arranged in a triangle? You'll find something!

Simple, huh?

And what if that doesn't work? A couple of suggestions. First of all, how certain are you of your last fix? The only two times I've ever got really lost were both through mis-identifying a fix, adjusting my situational awareness incorrectly based on the bad fix, and then realising many minutes after that that something had gone wrong. Have you made any corrections due to being blown off course? If so, are you certain that the corrections were correct? I hope you made a note of what corrections you made, because it's now that you need to use your log to try to figure out your actual track made good since you made that bad correction - and if you don't remember your correction, that will be tricky! I said that log would be important!

Another option, if you're certain of at least roughly where you are, is to find an unmistakable line feature and fly towards it. A coast is superb, but if there isn't one around, a large road is probably best. Once you find your line feature, fly along it until can get a definite fix from a feature along the line - a bend, or a juntion, or a town for example.

That should be enough to start some other people thinking, and adding more suggestions!

FFF
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Mak

21st Oct 2002, 10:46

Hi all,

From my (very narrow) experience I think that in the uk (SE at least), if I look at the map every 5-10 min (I do is as part of freda checks) it is difficult to get totally lost. When I think I don't know where I am it is generally down to not looking far ahead enough.

So first I'll be looking at the ground, then at the map, cross checking several visual references. Water features and tall features (masts, water tanks) seem make good choices, even though I never had the experience of flying in bad visibility. Ground elevation is also useful for far-away references but not of much use if you're flying over it.

If that doesn't work I'd then I'll use VOR/ADF triangulation and for that it helps to orbit over a significant feature so that once I have the fix you can more easily check with the map. Lacking the right gear it may be time for a pan call. From the stories I've heard even experienced pilots can get lost when flying visually so there's no shame in that.

Hope this is useful,
Mak

khorne

21st Oct 2002, 12:18

It seems that this post was put up by accident from 1975.

Surely no-one has any excuse for getting lost in 2002! A simple GPS can be bought for not much more than an hours flying and one with an aviation database is only about double that. How can anyone afford to fly and still not have one in the bag "just in case". If you get lost then you have to rely on a rather primitive method during which you may infringe airspace or run low on fuel. I would never use anything else as my primary method of navigation but if you want to use a stopwatch then go ahead but keep a GPS in the aircraft .

Hersham Boy

21st Oct 2002, 12:37

I do agree with the GPS point (if the technology is there... use it!) but it could lead to laziness and inability to use DR is the early days I guess.

My tip would be this: make sure you know how to use the VOR radionav equipment (if the a/c you're flying has it). Once you're really sure how it works (as opposed to just about being able to blag it!) it is very simple and, particularly in the SE where there are plenty to use, you can make an accurate fix in about half a minute.

I intend always to use VOR equipment when flying solo just as a second check to my DR navigation. Until I weaken and splash out on a fancy GPS, anyway ;)

Hersh

FlyingForFun

21st Oct 2002, 12:43

It's important to be very careful using GPS if you're lost. It can be invaluable. It can also get you into trouble.

How many gliding sites are on your GPS database? How about parachuting sites? Masts? And even if every danger area is in the database, the Notes that go with many of them won't be.

GPS is great for telling you where you are. As long as you're near somewhere which you can identify on the moving map, of course. But I'd never blindly follow a heading the GPS gave me, because I don't know where it's going to take me.

If you want to use a GPS to help you out if you get lost, by all means get the GPS to tell you where you are. Then locate your position on your chart, draw a line to where you want to go, and check that line doesn't take you anywhere you don't want to be.

This is one reason why I might prefer to use a VOR if I was lost - I'm going to transfer my position onto a chart anyway, and a VOR fix is very easy to transfer onto a chart. A GPS fix, although it's easier to obtain, is slightly harder to use once you've obtained it.

IMHO.

FFF
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Rod1

21st Oct 2002, 12:48

I guess the good old “Circle of uncertainty” is no longer in use then?

Rod

tacpot

21st Oct 2002, 12:58

I find it useful to write on my chart (in chinagraph) a time next to each fix I positively identify. (These times shoud be rubbed before the return journey!).

If you get lost you, instantly know the last place and time you knew where you were! Great for drawing your circle of uncertainty.

Been lost - didn't like it.

Windy Militant

21st Oct 2002, 13:18

Thought I was lost on Saturday but it turned out we were exactly where we should have been. However the river marked promenently on the chart, which should have a confirmed where we were was almost impossible to see. In fact we only spotted it on the reciprocal leg.
Has any one else been thrown by the symbols on the map showing features such as roads and rivers being more prominent than the features themselves. Very often a bold Red or Blue line on the map is nearly impossible to see on the ground.
As stated water features are very good land marks but be aware of flooding which may change the shape.
Motorways are also very good markers especially some of the bigger junctions or interchanges.
Power stations also make good land marks especially those with large cooling towers.

EI_Sparks

21st Oct 2002, 13:18

Hmmm. Relying on a GPS box. *shudder*
I'd not want to have ONLY a GPS box I think - I remember going to a conference a few years ago and watching a paper being presented by a group that had tried to automate a lumber yard with GPS systems as the navigation sensors (okay, I'm a robotics geek :D). Anyway, the big forklift they were testing was doing fine, tootling all over at 20-30 mph or so and all was well - until it came close to a building that had a large amount of steel in it. Suddenly, bingo - multi-path-propagation for the GPS signal and the forklift thought it was 20 yards too far to the left and so turned and made for the wall with a full load in the tines, doing about 25mph :) The human supervisor managed to stop it with about 3 feet to spare....

Anyway, moral of this story (and a hundred more about electronics that blew up unexpectedly) is that nothing is completely reliable, so if you have a critical system, it's better to have redundant backups.

Besides, at least over here, navigation is pretty simple - look down. See land? Yup, still in Ireland so :)
Okay, around dublin that's not good enough, but still, it's a good start :)

FlyingForFun

21st Oct 2002, 13:33

Windy - yes!

I think rivers, unless you know the area and you know the river is large and easy to spot, make bad way-points. But as a general rule, I wouldn't consider myself lost until I'd missed at least two way-points - it's far too easy to miss one, even if the chart is completely accurate.

Last year I was flying a friend around Arizona - no planning, just a general idea that we'd go east. That was one of the two times when I've really been lost. I flew over a ridge, and expected to see a lake directly in front of me. No lake there, but I saw a similar-shaped lake a few miles to my south. So I flew south, confident that I now knew where I was. After that, I couldn't get anything on the chart to match what I was seeing on the ground. Eventually I spotted an airport which I recognised - and it was only by luck that I was above that airport's class D and below the Sky Harbour's class B!

I flew back there a few days later, and figured out that the lake I'd been looking for was dry. The lake I'd found was marked on the chart - it was a very similar shape, but much smaller than the one I was looking for.

So yes, rivers can definitely dry up, as can large lakes!

FFF
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What a Loop

21st Oct 2002, 14:15

Flying for Fun

Know exactly what you me about Arizona, did the same this summer, one of my way points was " The horseshoe Dam", easy to find you'd think, not when its dry and all else round about looks the same. Eventually trundeled back to McDowell Mountains and started again.

Point being it may look different than you expect it to, so make sure you know some of the noticable features round about it to use as a back up. The deset looks mighty dry from 10,000ft:D :D :D

WAL:)

sennadog

21st Oct 2002, 14:23

Some good points so far but I really don't want to get into the usual bun fight about whether using GPS is a good idea or not.

Suffice to say, that IMO you should be capable of using DR,GPS,VORs etc as part of your Navigation skills to a high level.

I've seen people sailing with GPS who haven't got a clue how to DR on a boat and that is worrying. I'm not that comfortable with GPS in an aircraft as yet but I wouldn't want to rely on my skills at the moment as I'd have my head buried in the aircraft without being able to scan properly.

Each method needs to be learnt and applied properly.

'nuff said.......

knobbygb

21st Oct 2002, 14:35

I'm no expert, having a total of about 8 hours navigation experinece, but I have to agree with Windy Militant about how difficult features can be to spot that look very clear on the map (and vice-versa). I have particular trouble with railway lines which are often hidden in cuttings or behind tree-lines etc.

One thing I find useful is to carry both half-mil and quarter-mil maps of my route. Although I only use the half-mil for primary navigation, it's surprising how much easier it can be to identify small towns and villages by their shape on the quarter-mil. Many other features, such as railway stations, minor roads and the runway pattern at airfields, to name just a few, are much clearer on the larger scale map. I find the quarter-mil way too cluttered for normal use, but invaluable as a back-up to confirm your position. I've been lucky so far, as I'm one of the ones that is "going to be lost", and not "been lost" (yet).

FlyingForFun

21st Oct 2002, 14:44

Agree with knobby re. railway lines. With practice, they get easier to spot... the trick is not to look for a railway line, but to look for a long line of trees :) I'm not good enough at it yet to rely on it, but I often spot railway lines by seeing the line of trees, then cross-check to the chart.

I also agree re. runway layouts. I don't understand why we don't have runway layouts on 1/2-mil charts. Very useful navigation aid, and also helpful for planning arrival and departure. Of course, for airfields with an instrument approach outside of controlled airpsace, the chart will show you the orientation of one runway, which is better than nothing.... but certainly not ideal.

FFF
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QNH 1013

21st Oct 2002, 21:39

Surprised no-one seems to use QDM from a couple of ground stations. Very easy and quick, and you only need a radio and a map - you've got a map I hope.

All the suggestions for identifying ground features are fine and I agree with most of what has been posted but if you're ever lost in poor visability its completely different and much harder to read from ground to map because you can often see nothing significant, or at best a single feature. The circle of uncertainty on your map and radio or radionav fixes are then your best bet.

Re GPS, I have often heard people say that if its working at all it is accurate, so they believe it. This is not so. I have personally seen a gps (non ifr certified) give a bearing 30 degrees in error.

Final (comforting) thought... At the Battle of Britain Airshow at Biggin Hill two years ago a couple of F16s didn't appear at the slot time. The PA then announced that they were displaying over Kenley (must have caused a surprise). So if pilots who have had millions of pounds of flight training can get it wrong, perhaps we shouldn't feel too bad if we are, ahem, temporarily uncertain of position.

Rod1

23rd Oct 2002, 10:45

I had radio failure when I was very low time. Like an idiot I tried to fix the problem and got comprehensively lost. It was one of the most unpleasant experiences I have had, as I could not ask for help – no radio or transponder.

More by luck then judgment I stumbled across a good fix and managed to sort myself out from there. I started arranging my IMC the next day, and since passing have never been lost. The above happened before the GPS craze had taken off, a hand held was about £1000 ish.

I suspect getting very lost was much more common back then, and the IMC solution was the obvious next step. I am now considering building a PFA aircraft, which will not have all the toys I have now. I am very concerned about the potential consequences of getting lost without the VOR / DME ADF solution which I have used as my main nav for many years.

no sponsor

23rd Oct 2002, 14:22

My visual navigation is pants. The main problem is using the 1:500K scale map. It's much easier to use the 250K, since for proper visual navigation, you need to see much more than the occasional VRP (which I can never normally figure out on the larger scale map).

If you must, plan the route via obvious sights: lakes, funny shaped towns, big aiports like EGLL. (OK so the last one is not such a good idea).

I've avoided a GPS. There are plenty of ways to get around on radials and the like. Buy a Jepesson flight guide, which will have the correct radials for the approach to all airfields.

You might want to get IMC rated too.

Tinstaafl

23rd Oct 2002, 14:35

This is an extract of the lost procedure out of my syllabus from when I was a CFI.

---------------------
a. Aircraft established in endurance configuration;

b. Check made of fuel endurance and if low, action considered for a possible precautionary search and landing;

c. Intentions notified to ATC or FS;

d. Check made of compass and DI accuracy;

e. Check made of flight planned heading and ETA for accuracy;

f. Assessment made of probable track made good;

g. D/R position calculated;

h. Search made of most probable position;

i. Climb made to a higher altitude if necessary to increase map reading range of vision;

j. Track made to a known prominent feature if unable to pinpoint or fix position, or reciprocal heading steered to return to the last fix.

k. Assistance sought from ATC or FS if required; and

l. Use made of radio navaids.

FlyingForFun

23rd Oct 2002, 14:45

Tinstaafl,

Track made to a known prominent feature if unable to pinpoint or fix position, or reciprocal heading steered to return to the last fix.
Surely if you're not where you should be, steering a reciprical heading won't get you back to the last fix? At best, it will leave you the same distance from you last fix as you currently are from your intended position. At worst, if there's a strong, unforecast wind, for example, you'll be twice as far from your last fix as you currently are from your intended position. The only time I can see that this would work is if you steered an incorrect heading, and you knew what heading you'd steered - but in that case, surely you're not lost, you're just not where you intended to be? :confused:

All your other points are excellent though. Especially climbing for a better view (as long as the cloud-base allows) - don't think anyone else had mentioned that one yet.

FFF
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FWA NATCA

23rd Oct 2002, 16:20

Sennadog,

The suggestions so far have been right on the mark. But the most important thing to do is to ADMIT that you are lost then effectively and efficently work out the situation.

Being an air traffic controller I've had many pilots call on frequency that were lost, getting lost is not limited to general aviaition pilots so don't ever become embarrased when you do get lost. Just last year I had a military C17 at FL310 call on lost due to an electrical failure.

Air Traffic Controllers utilize the following methods to locate a lost pilot listed in order of preference is: Radar Identification, VOR orientation, DF equipment (which is not as available as it use to be) prominant land marks (lakes, highways, buildings, etc), another aircraft (someone hopefully with DF).

I can not stress enough the importance of recognizing that you are in a situation (lost) soon enough and asking for help.

Mike

Southern Cross

23rd Oct 2002, 16:50

At the risk of being shot down by fellow PpruNers who are no doubt far better navigators than I , I just cannot understand why so many people are so scathing about GPS. It is a wonderful piece of modern technology and a very accurate aid to navigation. Not designed to replace a chart nor eyeball. But used in conjuction with said items, much easier to interprete and use than for example an ADF - and quite likely to be much more accurate as well.

I am not IR rated but do have an IMC rating so have done a modest amount of instrument flying.

If one uses the GPS to do no more than verify position using the moving map - does it look the same with the chart you are holding and the countrywide you are seeing (?), then it adds an enormous amount to peace of mind and at least in 96% of the time (according to some study in the UK that I vaguely recall reading recently), accuracy, as to one's location.

Like any aid to naigation, GPS is not 100% reliable. Neither though is ADF - VOR probably usually better that ADF I will admit. But just as GPS units can fail, so to can one's traditional nav instruments.

I too subscribe to the view that if you can afford to buy a simple GPS unit and have the smarts to take time to learn to use it quickly and efficiently, why wouldn't you?

nonradio

23rd Oct 2002, 17:18

Probably stating the bleedin' obvious, but:
1/ accurate ETAs, or at least ETEs for checkpoints - so many folk have no idea when the 'fix' is coming up either looking too soon and worrying when it's not there, or too late and it's beeehiind yooou....
2/ Before you go think about line features (ie you can't miss them!) that you can fly toward and then follow until some positive ID-able feature turns up.
3/Always use at least 3 unique features to positively ID a checkpoint
4/ Draw a small diagram on the 1/2 mil of the runway layout next to your destination AD if you might have difficulty orientating
5/Practice makes perfect!
And finally if the vis is less than 5k, visual nav with compass, clock and map is going to concentrate the mind.

Chuck Ellsworth

23rd Oct 2002, 18:31

FFF:

A portable GPS would have saved you all that uncertainty re. position and airspace relation.:D :D

Cat Driver:

Sensible

23rd Oct 2002, 21:28

I was happily flying on a Lowrance Airmap GPS when a "position lost" message appeared on the screen. I was flying along a mountain range looking for a particular mountain pass in limited vis. Kept on the same course waiting for the GPS to "rediscover" it's position but it didn't!!!!!!! Because restricted airspace was around me, I did a 121.5 call and was vectored to an airport by ATC.

I learned some lessons that day: 1. Never rely solely upon GPS navigation, use VOR's or VFR navigation in future as secondary back up! 2. When the current position is "lost" note time and airspeed for a rough calculation on approximate position later - at 120kts., 15 minutes here or there is a lot of distance! As it was, I had been lost longer than I had guessed and my position was actually over the map fold so looking for my position on the VFR chart was futile anyway because I simply wasn't even close to where I had estimated to be.

Don't rely on GPS, it simply isn't infallable.

paulo

23rd Oct 2002, 22:23

Only two things to add to the good stuff:

1. Get lost early - getting lost later is much more lost! (FFF's threshold of second missed waypoint sounds sensible)

2. (aeros people): Assuming you can't cage DI gyro, drill yourself into DI reset after the fun and games. All too easy to think "hey, I just went out to the practice area, now that I know I'm still there, I'll just point the DI and go home!

Note 2 is primarily aimed at me, I don't have a drill for this yet and so this topic reminds me I've got something to fix. :)

Chuck Ellsworth

23rd Oct 2002, 23:25

Sensible:

I have used two Lowrance Airmaps for the past seven years or so, their reliability has been fantastic.

To address the mountain issue I have used them in the Alps, the pyrnees in Spain, the Canadian Rocky mountains and all the way to the southern United States, the Andean range in South America and every major mountain range in Africa. Never had a terrain caused loss of position.

Where was your GPS antenna? Could be it was not seeing enough of the sky?

Chuck E...

Sensible

24th Oct 2002, 07:17

Chuck, I was using the antenna detached from the GPS with the window sticker. I was flying a PA28 181 and I placed the antenna close to the bottom of the windshield. Wether it was electrical interference from the engine or the fact that the antenna was not flat I don't know. Another issue was the fact that after I had left the airport, I didn't need the GPS until the pass because I only needed to follow the mountains. After "position lost" message, a while later "GPS cold start" message appeared and it may be that the GPS was unable to orient itself again because of either the continual shift of aircraft position or the electrical interference from the engine. Usually and since, I leave the antenna attached to the GPS which is in turn attached to the to the yoke in the right hand seat.

S

Grim Reaper 14

24th Oct 2002, 14:42

I would always try one of the following:-
- Stop at a petrol station and ask (most of them have a road atlas);
- Fly low enough to read road signs;
- Throw a note out to someone, which encourages them to write down their answer and throw it back to you;
- Ditto the above, but ask them to paint your location on the tarmac of a local car park;
- Use D&D:rolleyes: They'll triangulate your radio transmission, rather than spot you on radar, giving you a spot-on position.

It's a toughy, but one of the above will serve you well. The decision as to which one (when you really are lost) is up to you.

And all you helo bods out there can stop looking smug about being able to use the first one.

Chuck Ellsworth

24th Oct 2002, 15:34

Sensible:

The Lowrance Airmap will sometimes have difficulty finding the satellites if for some reason it loses them, especially if there is a big position change. The cold start message is your clue, what you do is shut off the GPS and re start it thereby rebooting its computer and it will very quickly pick up the satellites as long as the antenna is able to see them.

I always position my antennas so they can see all the sky and have only had two temporary signal losses in tens of thousands of miles of flying. One loss was approaching Bamaco Mali in Africa and the other one was near Bordeaux France. In both cases recapture of the satellites was less than thirty seconds.

I also mount my GPS's on the insrrument panel glareshield which puts them in the line of sight like a headsup display, thus no need of looking down to read them.

I run an Anywheremap on one side and a Lowrance Airmap on the other side.

Bulletproof navigation...... Far better than the steam guages in the airplane panel. ( Of course we use all the airplane Nav. aids so as to be legal and have " ALL "the info to work with. )

And before anyone gives me any of that crap about how to navigate with a map and Abaccus forget it, I have been flying IFR since 1957.

Cat Driver:

QDMQDMQDM

24th Oct 2002, 20:18

I too subscribe to the view that if you can afford to buy a simple GPS unit and have the smarts to take time to learn to use it quickly and efficiently, why wouldn't you?

Exactly. This seems so axiomatic I find it impossible to understand the holier than thou attitude which views GPS as the spawn of the devil. Look at Chuck's postings in this thread and he is not alone amongst experienced pilots.

I went to pick up my aircraft with the fellow who was going to instruct me to get my licence back. Wanting to appear a good-goody eager beaver I said I wouldn't bother bringing my newly-purchased GPS as between the two of us I was sure we'd be able to map read it. His response was, broadly: "Bollocks to that, I'm bringing mine then!" He first soloed in about 1950 and has been flying continually -- RAF, BOAC and GA -- ever since. People like this know what they're talking about and have no patience with all this pussy-footing about. When you need to know where you are, you need to know where you are and it is appropriate to use any means, fair or apparently foul, to do so.

QDM