VFR navigation question
Thread Starter
Joined: Sep 2006
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From: London
VFR navigation question
Hi folks
I've just discovered that, although I've lived in North London for several decades, I don't recognize any of it from the air. I haven't been flying for long, and of course my flying instructors seem to know their way around, but I don't know if that is because of long familiarity with the area when airborne, or some other navigational skill you have to develop.
I've tried looking at aerial photos and trying to line up what I see with roads, towns, etc; and I can do this (sort of) for my area. But what I see from the cockpit doesn't really look like an aerial photo.
Is there some exercise for getting better at this? Or am I missing something?
Any advice gratefully appreciated.
I've just discovered that, although I've lived in North London for several decades, I don't recognize any of it from the air. I haven't been flying for long, and of course my flying instructors seem to know their way around, but I don't know if that is because of long familiarity with the area when airborne, or some other navigational skill you have to develop.
I've tried looking at aerial photos and trying to line up what I see with roads, towns, etc; and I can do this (sort of) for my area. But what I see from the cockpit doesn't really look like an aerial photo.
Is there some exercise for getting better at this? Or am I missing something?
Any advice gratefully appreciated.
Joined: Oct 2001
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From: The Beautiful South
It will come with practice...............get your instructor to tell you how he does it..........more than likely he has spent many hours over the same area.
One town can look very similar to another so I always look for line features first..........Rivers, Railways, major roads, then distinctive features like power stations, lakes and large woods . keep in mind that the view can change very dramatically with different visibility, time of day, and seasons throughout the year.
Rgds cirrus01
One town can look very similar to another so I always look for line features first..........Rivers, Railways, major roads, then distinctive features like power stations, lakes and large woods . keep in mind that the view can change very dramatically with different visibility, time of day, and seasons throughout the year.
Rgds cirrus01
Joined: Jun 2003
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From: EuroGA.org
I am sorry to give a useless reply but I think the answer is "it's hard".
That's why dead reckoning is not half as good as they make out when they teach it in the PPL (while slagging off GPS).
The #1 trick in dead reckoning navigation is picking ground features that are unique within a reasonably wide area. For example no use picking a lake as a waypoint when there is another one 2nm away, especially if the other one is even vaguely similar. (Picking the group of two adjacent lakes, with say the smaller one on the left, might be a better idea in this case). Same with towns & villages and that's hard because so many villages look exactly alike. It's easy along a coast which has plenty of curves and nicks in it; you just tick them off on the chart. Roads are hard to use; if using them one should pick up on a weird looking intersection which one isn't going to see every few miles. Railways are often hidden in vegetation and can't be verified unless one is on top of it by using a GPS first; it's said that the clue is the straight lines and gentle curves but plenty of hedges do that also.
The #2 trick is not to just fly for X minutes and then start looking for the expected ground feature. One should check off other (probably less obvious) features down below as one is progressing along the route. This is how you do street-level nav from a map in a car; you (or preferably a passenger) check off each street as you pass it. Obviously this jacks up the cockpit workload, but some people like it
That's why so many official VRPs are useless - except for the locals who can't possibly understand how anybody can fail to recognise them.
None of this stuff works on nice hazy English summer days
Specialised units (e.g. S&R helicopter pilots & the military) get specialised training and lots of currency, plus they tend to know the area. Plus they use a GPS whenever it's useful.
That's why dead reckoning is not half as good as they make out when they teach it in the PPL (while slagging off GPS).
The #1 trick in dead reckoning navigation is picking ground features that are unique within a reasonably wide area. For example no use picking a lake as a waypoint when there is another one 2nm away, especially if the other one is even vaguely similar. (Picking the group of two adjacent lakes, with say the smaller one on the left, might be a better idea in this case). Same with towns & villages and that's hard because so many villages look exactly alike. It's easy along a coast which has plenty of curves and nicks in it; you just tick them off on the chart. Roads are hard to use; if using them one should pick up on a weird looking intersection which one isn't going to see every few miles. Railways are often hidden in vegetation and can't be verified unless one is on top of it by using a GPS first; it's said that the clue is the straight lines and gentle curves but plenty of hedges do that also.
The #2 trick is not to just fly for X minutes and then start looking for the expected ground feature. One should check off other (probably less obvious) features down below as one is progressing along the route. This is how you do street-level nav from a map in a car; you (or preferably a passenger) check off each street as you pass it. Obviously this jacks up the cockpit workload, but some people like it
That's why so many official VRPs are useless - except for the locals who can't possibly understand how anybody can fail to recognise them.
None of this stuff works on nice hazy English summer days
Specialised units (e.g. S&R helicopter pilots & the military) get specialised training and lots of currency, plus they tend to know the area. Plus they use a GPS whenever it's useful.
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From: He's on the limb to nowhere
I am sorry to give a useless reply but I think the answer is "it's hard".
That's why dead reckoning is not half as good as they make out when they teach it in the PPL (while slagging off GPS)
That's why dead reckoning is not half as good as they make out when they teach it in the PPL (while slagging off GPS)
mad_bear. Pick things you can see from a distance. Pick things you cannot easily mistake for something else. Don't pick things where there are two of them close together. When picking landmarks, plan so you can see your next but one landmark before you get to the next landmark. Pick landmarks where two lines cross eg motorway intersections. Quite simple really.
Joined: Sep 2006
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From: 10 west
go fly with a friend ( or pay to have your instructor do it ) and LOOK...do'nt fly.admire and look for landmarks you recognise.remember of course that these will change with height so the hills you recognise one day may not be so obvious the next day if you are higher.
why dont you go google earth..you can sit in one place and look at ground features for as long as you like...sometimes distorts elevation features but you can lower yourself and still see anything that is relatively high..
type in GOOGLE EARTH to your search facility, download and off you go...
remember you will need to be on broadband...
strikes me however if you have been training in the locality you should get to know the ground features...but maybe you have not done too many lessons yet ..and i assume this from your post so do'nt worry it will come with time...anything outside or your area is only of passing interest so to speak....
concentrate on the horizon for the moment (...pitch/attitude..!!)
why dont you go google earth..you can sit in one place and look at ground features for as long as you like...sometimes distorts elevation features but you can lower yourself and still see anything that is relatively high..
type in GOOGLE EARTH to your search facility, download and off you go...
remember you will need to be on broadband...
strikes me however if you have been training in the locality you should get to know the ground features...but maybe you have not done too many lessons yet ..and i assume this from your post so do'nt worry it will come with time...anything outside or your area is only of passing interest so to speak....
concentrate on the horizon for the moment (...pitch/attitude..!!)
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From: EuroGA.org
Slag
IO540, What mad_bear is descrbing is called pilotage, not dead reckoning. Learn your stuff before you slag it off.
mad_bear. Pick things you can see from a distance. Pick things you cannot easily mistake for something else. Don't pick things where there are two of them close together. When picking landmarks, plan so you can see your next but one landmark before you get to the next landmark. Pick landmarks where two lines cross eg motorway intersections. Quite simple really.
You don't miss one chance to take the mick out of stuff I write. Not sure why; I don't think we have met and I refused to buy you a beer, etc. Why don't you forget the slagging off and spend the time saved typing a worthwhile contribution to knowledge.
In this case, you take the mick and then go on to paraphrase half the stuff I wrote.
IO540, What mad_bear is descrbing is called pilotage, not dead reckoning. Learn your stuff before you slag it off.
mad_bear. Pick things you can see from a distance. Pick things you cannot easily mistake for something else. Don't pick things where there are two of them close together. When picking landmarks, plan so you can see your next but one landmark before you get to the next landmark. Pick landmarks where two lines cross eg motorway intersections. Quite simple really.
You don't miss one chance to take the mick out of stuff I write. Not sure why; I don't think we have met and I refused to buy you a beer, etc. Why don't you forget the slagging off and spend the time saved typing a worthwhile contribution to knowledge.
In this case, you take the mick and then go on to paraphrase half the stuff I wrote.
Joined: Oct 2001
Posts: 277
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From: London
Slim_Slag.. what you are describing is "Feature Crawling".
The WORST type of navigation, the refuge of people who have a talent for nothing more sophisticated.
It's people like you being here that make other forums more enjoyable.
The WORST type of navigation, the refuge of people who have a talent for nothing more sophisticated.
It's people like you being here that make other forums more enjoyable.
Joined: Nov 2001
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From: England
Not much to add to the advice given above, just an anecdote from my own experience to back it up!
When I first started student cross countries from my home base of Netherthorpe, I always had diffuculty spotting the airfield (field being the operative word here - in amongst lots of other, mostly bigger, fields!). The trick, when I discovered it, was as noted above - stop concentrating on the field itself and look for more obvious landmarks (like the large wood and the quarry).
Kirsty - not sure I can agree with you - identifying obvious features to right or left or on track is surely an effective method? I would consider feature crawling to be zig zagging on and off intended course to overfly said features.
p.s. Or maybe I'm just rubbish at navigation!
When I first started student cross countries from my home base of Netherthorpe, I always had diffuculty spotting the airfield (field being the operative word here - in amongst lots of other, mostly bigger, fields!). The trick, when I discovered it, was as noted above - stop concentrating on the field itself and look for more obvious landmarks (like the large wood and the quarry).
Kirsty - not sure I can agree with you - identifying obvious features to right or left or on track is surely an effective method? I would consider feature crawling to be zig zagging on and off intended course to overfly said features.
p.s. Or maybe I'm just rubbish at navigation!
Joined: Oct 2001
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From: London
My initial advice would be don't worry about it. The problem mad_bear has is he's too busy trying to learn to fly an aeroplane to worry too much about working out where is and how to NAVIGATE from A to B. He needs to work out the nuts & bolts of getting the aeroplane to do what he wants and to understand what and how this is all happening. As he gets the hang of that a little more then he can split his looking out of the window time between "seeing & avoiding" and taking in his surroundings. It's not a black art navigating. But is best learnt when one can handle an aeroplane safely without it taking 95% of ones brain power.
When it comes to nav I agree in many respects Slim. Good nav is dependent much more on knowing what's between the waypoints and where you should be in relation In my OPNION new PPLs spend too much time with Whizz Wheels. Hours are spent planning a route, working out the wind and calculating times to the nearest millsecond. All of this based around the assumption that the wind speed and direction is going to be exactly as forecast and that the compass, DI will be perfect and nothing will come up to make the pilot change is flight at all.
For me? If I'm heading north and the wind is from the east then I'll just add a few degrees and amend my heading en route. The forecasters are guessing so why can't i a little bit? If there's a bit of a headwind I'll add a few minutes to my estimate etc etc.. this side of the flight planning I'll do en route and make changes as i see fit.
This frees up more time to check weather, notams and most importantly go over the planned route. The number of PPLs I see who do the maths beautifully and then dive into an aeroplane without actually LOOKING at where they're going and what they expect is amazing.
That said, all the above works for me.. may not work for others. I use GPS, not as a sole means of nav, but if I spot a town, I work out where I think it should be and then I don't use three distinguising features.. i look at the GPS!
When it comes to nav I agree in many respects Slim. Good nav is dependent much more on knowing what's between the waypoints and where you should be in relation In my OPNION new PPLs spend too much time with Whizz Wheels. Hours are spent planning a route, working out the wind and calculating times to the nearest millsecond. All of this based around the assumption that the wind speed and direction is going to be exactly as forecast and that the compass, DI will be perfect and nothing will come up to make the pilot change is flight at all.
For me? If I'm heading north and the wind is from the east then I'll just add a few degrees and amend my heading en route. The forecasters are guessing so why can't i a little bit? If there's a bit of a headwind I'll add a few minutes to my estimate etc etc.. this side of the flight planning I'll do en route and make changes as i see fit.
This frees up more time to check weather, notams and most importantly go over the planned route. The number of PPLs I see who do the maths beautifully and then dive into an aeroplane without actually LOOKING at where they're going and what they expect is amazing.
That said, all the above works for me.. may not work for others. I use GPS, not as a sole means of nav, but if I spot a town, I work out where I think it should be and then I don't use three distinguising features.. i look at the GPS!
Blah Blah Blah
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From: Malmesbury VRP
At the ned of the day it all comes down to time an experience. You have your license you know know the theory.
As with anything theory does not all ways seem to tie up with the practical.
I used to live on the Isle of Man. Now this is a tiny island which is easy to navigate around on the ground, it is also fairly easy to navigate around from the air. Trying to pick out a specific village can be tough even on the Island. After a while it became easy. I flew quiet a lot with a well seasoned pilot who knows the Island from the air. He gave some cracking pointers on how recognise the various places from the air.
But all in all...time and experience.
Don't sweat it. As long as you know roughly where you are and are not busting airspace and know where you are going, you will be fine.
As with anything theory does not all ways seem to tie up with the practical.
I used to live on the Isle of Man. Now this is a tiny island which is easy to navigate around on the ground, it is also fairly easy to navigate around from the air. Trying to pick out a specific village can be tough even on the Island. After a while it became easy. I flew quiet a lot with a well seasoned pilot who knows the Island from the air. He gave some cracking pointers on how recognise the various places from the air.
But all in all...time and experience.
Don't sweat it. As long as you know roughly where you are and are not busting airspace and know where you are going, you will be fine.
Joined: Feb 2002
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From: london uk
The best advice i had from my instructor was this "FLY THE NUMBERS". Do your plog and then set off overhead the field(as departing straight out can put you a few miles off before you even start) and fly the numbers. Concentrate on heading and altitude, dont forget your freda's every 15 mins or so and try to look out the window at angles of less than 30 degress below the horizon. Looking down at what your almost ontop of is not really going to help you. I agree with IO540, GPS is the way to go and it should be covered in some detail in the syllabus, in however many years GPS has been up and running i cannot think of one instance where it has been intentionally turned off. That was always the reason trotted out for the reluctance to embrace the technology. Whilst on the subject of GPS, a note of caution for you all before putting your complete trust in GPS. My freind was on a holliday in the Carribean on a chartered yacht and bought a GPS to navigate. His words were "It guided me litteraly into the harbours even in thick fog". So when we were on a long leg, Cark back to Stapleford, he had his hand held on and i was tracking LAM. My DME and VOR were telling me i was where i expected to be, but his GPS was saying we were about 15 miles off to the east which worried me due to Stansteads zone. I cross checked all the intruments ADF VOR 1 and 2 and i was sure that the kit in the plane, which had been there for many years was right and his GPS was wrong. He re-checked the co-ordinates from the pooleys for Stapleford and i looked at his entry on the screen and it was correct. However the vis was good enough for me to confirm my instruments were correct and his GPS wasnt. I must admit that if i were in IMC i would possibly have been inclined to believe the GPS
. As a sort of Thursday morning test, can any of you guess what was the problem with his GPS, as we did indeed arrive at Staplford on track and time??
. As a sort of Thursday morning test, can any of you guess what was the problem with his GPS, as we did indeed arrive at Staplford on track and time??
Thread Starter
Joined: Sep 2006
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From: London
Thanks for the replies.
As other have said, with my limited experience flying the plane requires 100% of my meagre brain-power, so I have little left for navigation. But I'm not really trying to navigate, as such; merely to recognize things in my local area. I have been surprised how difficult that is for me. Yesterday I flew over what ought to have been a highly distinctive landmark -- a 300-ft tall windmill. I can recognize it from miles away on the ground, but in the air I didn't spot it until it was pointed out to me. I found this rather disconcerting.
I appreciate that I don't `need' to be able to navigate yet, but I'm working on a very tight budget, and if there is anything I can practice on the ground that stands a chance of improving my skills in the air, I'm willing to give it a try.
I fly out of Elstree, and there are two (maybe more) VRPs marked on the chart within a few minutes flight. I really can't imagine that I would have recognized either of them from the air had they not been pointed out to me. Without being shown, I would have had absolutely no idea what a golf couse looks like from the air. I'm not sure how I would cope with recognizing VRPs I've never seen before.
I've tried Google Earth but, for far as I can tell, it can only view from directly above (unless other people know different). What I see out of the cockpit doesn't look the same. Maybe I can make the adjustment with practice, or maybe you have to have some built-in image processing skill that I lack.
As for GPS: I appreciate that this may be the wrong place for a moan but, when I started flying, it appalled me that GPS wasn't a standard part of training and of navigation examinations. I would have thought by now that a GPS unit would have been as essential a piece of cockpit equipment as a magnetic compass, and use of GPS an essential skill. It's not even particularly expensive. Of course a GPS unit can fail, but so can any other piece of equipment. Moan over
As other have said, with my limited experience flying the plane requires 100% of my meagre brain-power, so I have little left for navigation. But I'm not really trying to navigate, as such; merely to recognize things in my local area. I have been surprised how difficult that is for me. Yesterday I flew over what ought to have been a highly distinctive landmark -- a 300-ft tall windmill. I can recognize it from miles away on the ground, but in the air I didn't spot it until it was pointed out to me. I found this rather disconcerting.
I appreciate that I don't `need' to be able to navigate yet, but I'm working on a very tight budget, and if there is anything I can practice on the ground that stands a chance of improving my skills in the air, I'm willing to give it a try.
I fly out of Elstree, and there are two (maybe more) VRPs marked on the chart within a few minutes flight. I really can't imagine that I would have recognized either of them from the air had they not been pointed out to me. Without being shown, I would have had absolutely no idea what a golf couse looks like from the air. I'm not sure how I would cope with recognizing VRPs I've never seen before.
I've tried Google Earth but, for far as I can tell, it can only view from directly above (unless other people know different). What I see out of the cockpit doesn't look the same. Maybe I can make the adjustment with practice, or maybe you have to have some built-in image processing skill that I lack.
As for GPS: I appreciate that this may be the wrong place for a moan but, when I started flying, it appalled me that GPS wasn't a standard part of training and of navigation examinations. I would have thought by now that a GPS unit would have been as essential a piece of cockpit equipment as a magnetic compass, and use of GPS an essential skill. It's not even particularly expensive. Of course a GPS unit can fail, but so can any other piece of equipment. Moan over
Joined: Jan 2001
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From: He's on the limb to nowhere
Ho Ho,
Didn't take long to turn a question about recognising visual features into a "GPS is the only way" thread.
How about a navigation thread which doesn't mention GPS? mad_bear wants to know how to fly visually, looking out of the window. How about we stick to the original question? I know there are people on here who love a rant and will turn any subject their way, but lets knock it on the head for this thread, eh?
So to feature hopping.
I've said it before and I'll say it again, the PPL syllabus does a poor job of equipping people to fly outside of the local area. In fact a freshly qualified PPL is barely competent to take passengers more than 10 miles from the airport. IMO. So mad_bear, don't get all worried that you cannot easily do things when you get your PPL, that's not your problem. The problem is that it's important to get people through the PPL quickly, so the system concentrates on the real basics i.e. you are safe.
So, as gcolyer says, it comes down to experience. What I want to see from a new PPL is a desire to head off to another airport 100 miles away to buy a burger. I don't want him to worry and make a mistake, and i don't want him to get lost. If he is just starting off and wants to fly a dog leg route using easily recognisable features then I say go for it. His achievement is getting to the burger, not the way he flies there. When he realises it is easy to reach another airfield and not get lost, then I'll tell him to not fly in a dog leg to the hill, fly abeam it. As he gets better at that, he can make his route even more straight.
If that means he has used The WORST type of navigation, the refuge of people who have a talent for nothing more sophisticated then so be it. I see a guy with a smile on his face as he managed to take a plane to go and buy a burger and get home in one piece.
I would encourage him to take a GPS as they are brilliant, but remind him that relying on gadgets to navigate falls into the WORST type of navigation, the refuge of people who have a talent for nothing more sophisticated
Didn't take long to turn a question about recognising visual features into a "GPS is the only way" thread.
How about a navigation thread which doesn't mention GPS? mad_bear wants to know how to fly visually, looking out of the window. How about we stick to the original question? I know there are people on here who love a rant and will turn any subject their way, but lets knock it on the head for this thread, eh?
So to feature hopping.
I've said it before and I'll say it again, the PPL syllabus does a poor job of equipping people to fly outside of the local area. In fact a freshly qualified PPL is barely competent to take passengers more than 10 miles from the airport. IMO. So mad_bear, don't get all worried that you cannot easily do things when you get your PPL, that's not your problem. The problem is that it's important to get people through the PPL quickly, so the system concentrates on the real basics i.e. you are safe.
So, as gcolyer says, it comes down to experience. What I want to see from a new PPL is a desire to head off to another airport 100 miles away to buy a burger. I don't want him to worry and make a mistake, and i don't want him to get lost. If he is just starting off and wants to fly a dog leg route using easily recognisable features then I say go for it. His achievement is getting to the burger, not the way he flies there. When he realises it is easy to reach another airfield and not get lost, then I'll tell him to not fly in a dog leg to the hill, fly abeam it. As he gets better at that, he can make his route even more straight.
If that means he has used The WORST type of navigation, the refuge of people who have a talent for nothing more sophisticated then so be it. I see a guy with a smile on his face as he managed to take a plane to go and buy a burger and get home in one piece.
I would encourage him to take a GPS as they are brilliant, but remind him that relying on gadgets to navigate falls into the WORST type of navigation, the refuge of people who have a talent for nothing more sophisticated
Joined: Oct 2001
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From: London
mad bear,
In terms of your meagre budget. I can see your thought process and your reasoning, but I didn't even consider navigation until I'd finished my solo circuit consolodation. I did what I needed to when I needed to. I also finished my PPL in 45 hours. Again knowing me and my limitations I would've taken longer if I'd have tried to do it all in one go.
obviously my advice and pistonones "Fly the numbers" are very much contradictory.. use what's best for you!
In terms of your meagre budget. I can see your thought process and your reasoning, but I didn't even consider navigation until I'd finished my solo circuit consolodation. I did what I needed to when I needed to. I also finished my PPL in 45 hours. Again knowing me and my limitations I would've taken longer if I'd have tried to do it all in one go.
obviously my advice and pistonones "Fly the numbers" are very much contradictory.. use what's best for you!
Guest
Posts: n/a
mad_bear,
Regardless of whether your technique is pilotage or dead-reckoning, there certain things you can do to make VFR altogther easier.
Apart from the basic speed/heading/timing, I think firstly, one must look at the route on the chart and pick things that you think will be easey to spot and plan to use those. The trick, as you have discovered, is to pick things that are easy from the air. Don't be tempted to try and id features by going ground to map. To remain in control maintain a map to ground philosophy. The ground to map id method essentially means you are no longer confident that you know where you are and takes much more time away from flying accurate headings. Also, always orientate your map so the direction you are travelling in faces forward/up - if you don't you'll get caught out one day!
Things which I find most easy to spot are:
The shape of large lakes
Complex Road Junctions
The shape of a town
The relative co-location of small hamlets
Parallel road/canal/river/active railway line
Stacks (towers, ariels).
Single carriageway road with dual carriageway sections.
Motorways
The way roads radiate from or orbit around towns. You have probably misidentified a town with four roads to the west if the maps shows only three.
Things are can be extremely difficult to find but tempting to use:
Windfarms - the big ones are easy, but the CAA chart sometimes suggests multiple when only one itsy-bitsy windmill exists
Minor roads, rivers and disused railway lines: They can all look the same!
Smaller lakes, some are shown, some aren't.
Disused airfields. Some stand out for 10 miles. Some are just marks on the ground. Same goes for some active airfields!
Once you get tuned in, you start using the following:
Forests
Pattern of high ground
Pure timing, because eventually you'll learn to have faith that maintaing your heading accurately for the right amount of time at the planned speed always puts you roughly where you planned to be
Regardless of the above, as others say, it is difficult. But general confidence comes from getting the brain to see how features are placed in relation to each other, rather than concentrating on finding a single feature. The former guards against mis-identification and help greatly with spotting the 'pattern' before you get there.
Regardless of whether your technique is pilotage or dead-reckoning, there certain things you can do to make VFR altogther easier.
Apart from the basic speed/heading/timing, I think firstly, one must look at the route on the chart and pick things that you think will be easey to spot and plan to use those. The trick, as you have discovered, is to pick things that are easy from the air. Don't be tempted to try and id features by going ground to map. To remain in control maintain a map to ground philosophy. The ground to map id method essentially means you are no longer confident that you know where you are and takes much more time away from flying accurate headings. Also, always orientate your map so the direction you are travelling in faces forward/up - if you don't you'll get caught out one day!
Things which I find most easy to spot are:
The shape of large lakes
Complex Road Junctions
The shape of a town
The relative co-location of small hamlets
Parallel road/canal/river/active railway line
Stacks (towers, ariels).
Single carriageway road with dual carriageway sections.
Motorways
The way roads radiate from or orbit around towns. You have probably misidentified a town with four roads to the west if the maps shows only three.
Things are can be extremely difficult to find but tempting to use:
Windfarms - the big ones are easy, but the CAA chart sometimes suggests multiple when only one itsy-bitsy windmill exists
Minor roads, rivers and disused railway lines: They can all look the same!
Smaller lakes, some are shown, some aren't.
Disused airfields. Some stand out for 10 miles. Some are just marks on the ground. Same goes for some active airfields!
Once you get tuned in, you start using the following:
Forests
Pattern of high ground
Pure timing, because eventually you'll learn to have faith that maintaing your heading accurately for the right amount of time at the planned speed always puts you roughly where you planned to be
Regardless of the above, as others say, it is difficult. But general confidence comes from getting the brain to see how features are placed in relation to each other, rather than concentrating on finding a single feature. The former guards against mis-identification and help greatly with spotting the 'pattern' before you get there.
Joined: Feb 2002
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From: london uk
Kirsty it was my instructors advice and i found it worked for me. To reinforce the reasoning, try doing dead reckoning the RAF way! They use an advanced DR technique called the IP technique. This involves picking a very prominent grond feature, something that is easily recogniseable from low level. No guesses as to why that particular requirement is necessary! This feature should be within 20 minutes of your target. Then using 1/4mil charts and OS maps, plan your route from said IP (initial point) to target in a STRAIGHT line. Mark off at five mile intervals and fly at a speed which is a multiple of 60. This makes it easy to compute eta, eg- 15 miles to run? 7.5 mins at 120Kn or 10 mins at 90Kn. Concentrate on flying THE NUMBERS and you WILL arrive at the target on time. The reasoning is obvious, its not too challenging to fly accurate NUMBERS for a period of 15 - 20 mins after finding the IP. So in summary, they fly numbers as it may not allways be possible to find suitable ground features every 10 miles! Think desert or sea
Joined: Oct 2001
Posts: 277
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From: London
"Concentrate on flying THE NUMBERS and you WILL arrive at the target on time."
Unless the wind is the opposite of what's forecast, unless your compass and DI are out, assuming you remember to make a note of the time at each way point. How do you make sure you fly at 60, 90 or 120kts. A 20 kt headwind component takes 20kts off your cruise speed.
If I'm flying down the VFR corridor from The Isle of Wight to Cherbourg, I'll have a good 45 mins in the air to assess what direction the wind is blowing from and how it's impacting my ground speeding and heading. So far everytime I've managed to pitch up in France within 5 mins of my estimate and within half a mile of my intended track!
Five years of flying, I've never been remotely uncertain of position. Not saying that will last! but my system works for me.
Have complete faith that your sums will get you where you want to go at your peril!!
Unless the wind is the opposite of what's forecast, unless your compass and DI are out, assuming you remember to make a note of the time at each way point. How do you make sure you fly at 60, 90 or 120kts. A 20 kt headwind component takes 20kts off your cruise speed.
If I'm flying down the VFR corridor from The Isle of Wight to Cherbourg, I'll have a good 45 mins in the air to assess what direction the wind is blowing from and how it's impacting my ground speeding and heading. So far everytime I've managed to pitch up in France within 5 mins of my estimate and within half a mile of my intended track!
Five years of flying, I've never been remotely uncertain of position. Not saying that will last! but my system works for me.
Have complete faith that your sums will get you where you want to go at your peril!!
Joined: May 2005
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From: UK
Joined: Feb 2002
Posts: 375
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From: london uk
Kirsty,
I would have thought most pilots would have assumed i meant ground speed, and not IAS, as flying into a 30Kn head wind at 90Kn would OBVIOUSLY make a big impact on your Actual time of arrival! So if you have flown say 100 miles to your IP, then you would have an accurate estimation of the prevailing weather conditions, wind included! This is why you only fly the last twenty minutes to your target with reference mainly on your numbers. I also said mark off your chart at 5 mile intervals, and see what is there and cross check that with your map and watch. Trust me it works!
""If I'm flying down the VFR corridor from The Isle of Wight to Cherbourg, I'll have a good 45 mins in the air to assess what direction the wind is blowing from and how it's impacting my ground speeding and heading. So far everytime I've managed to pitch up in France within 5 mins of my estimate and within half a mile of my intended track! "" So you have proved my point! What were you using to navigate accross the sea? I suspect time and heading were much more use than ground features! Or a GPS
Darth Bovine, the reason his gps showed bad info was user error, i n as much as he had the wrong datum for this side of the world! This would probably not have happened had he had training in the correct use of GPS, hence the need for proper training in its safe use!
I would have thought most pilots would have assumed i meant ground speed, and not IAS, as flying into a 30Kn head wind at 90Kn would OBVIOUSLY make a big impact on your Actual time of arrival! So if you have flown say 100 miles to your IP, then you would have an accurate estimation of the prevailing weather conditions, wind included! This is why you only fly the last twenty minutes to your target with reference mainly on your numbers. I also said mark off your chart at 5 mile intervals, and see what is there and cross check that with your map and watch. Trust me it works!
""If I'm flying down the VFR corridor from The Isle of Wight to Cherbourg, I'll have a good 45 mins in the air to assess what direction the wind is blowing from and how it's impacting my ground speeding and heading. So far everytime I've managed to pitch up in France within 5 mins of my estimate and within half a mile of my intended track! "" So you have proved my point! What were you using to navigate accross the sea? I suspect time and heading were much more use than ground features! Or a GPS
Darth Bovine, the reason his gps showed bad info was user error, i n as much as he had the wrong datum for this side of the world! This would probably not have happened had he had training in the correct use of GPS, hence the need for proper training in its safe use!