# Accuracy of the "1 in 60" rule for navigation.

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On 07/01/2020 at 2:05 PM, old man emu said:

But it is good to throw this "over thinking" around on these forums. Now I bet Apen will fly with the map on his knees and his eyes outside. After all, this is recreational flying. We don't have "air races" any more where it is essential to keep "on track, on time" to win the prize.

Yes. As I was destroying my brain doing the maths. BUT, now that the maths is done, it turns out that you have to think less, not more. The 1 in 60 rule is accurate up to being *really* off course. You don't have to think about it just being a rule of thumb.

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1 hour ago, Yenn said:

As others have said it is hard to judge distance off and I would not be waiting until I had gone 60 miles to try to fix my track, unless I had no other option.

In other words, this technique is pro-active because you are making constant corrections to heading as the drift changes. You are not blindly flying off on a heading based on a forecast, (which after all, is only a forecast!), to end up perhaps 30 mins later over country with no landmark you can ID.

It doesn't matter how your WAC is presented, (paper, EFB),  because you will have drawn your track onto it.

Has worked for me over many k of inland VFR flying.

happy days,

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Those sorts of tracking errors are of a large magnitude usually only done when you plot the wind on the wrong side or fly a distance as a track (or such). I've used it all my life, along with ground speed to distance "rough checks" like 130 knots is a bit more than 2 NM/minute.. 180 is 3 nm/minute. Such checks will expose any large errors and allow corrections to be made before anything becomes critical. .   There's no point having anything correct to the 3rd decimal place.. if the assumption it's based on is incorrect.  Nev

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On 07/01/2020 at 9:37 AM, old man emu said:

The 1 in 60 rule is a nice thing to know if you are flying very long distances at high speed, but to try to apply it for short flights at speeds below 100 kts is making the argument ad absurdum. Have a look at the presentation of the 1 in 60 rule in this video. The track lengths and off-track distances are very small, resulting in off-heading amounts of only a few degrees.

Now have a look at a typical gyroscopic compass face most people would use to monitor their heading:

See that the scale is marked off in 5 degree sections. That means that the most accurate heading you can fly is plus or minus 2.5 degrees from planned heading. Given the small size of the compass face, the most accurate is more likely to be 5 degrees. And I won't add in gyroscopic progression.

So, for those who day VMC flight, below 10,000 ft at speed below 100 kts, the 1 in 60 rule is a nice bit of theory, but not as practical as map reading.

Using Turbo's information, 0.5 nautical miles is about 925 metres. Since VMC visibility limit is 5000 metres (approx 2.5 nautical miles). Blind Freddy could see that far.

Another factor affecting off-track position is wind direction. If a pilot obtains the current weather before planning a flight, then the pilot will have a general idea of which side of the planned track the aircraft is likely to be blown to if the wind is greater or less than forecast. If a pilot is flying with a navigator (usually she who must be obeyed) the navigator can keep an eye on Track Made Good and advise heading corrections.

Well, well, well. I based my assessment of the 1 in 60 rule on the assumption that you would measure how far you had actually flown, not how far you had hypothetically gone down the original track. The video uses the example of the intended track. That version of the 1:60 rule will be accurate up to about 10 degrees off track, as others have said. Bob Tait, in his RA-Aus cross country endorsement seems to switch between methods.

Using the original track is easier because you don’t have to measure the hypotenuse.

The hypotenuse is the better method for navigation because, for example that is the only method that tells you your ground speed and allows you to determine what the winds actually are - not that I would attempt to do that alone in flight.

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On 07/01/2020 at 9:53 AM, turboplanner said:

And if you can see the 5000 metres and see you're off track, why not just adjust your heading slightly to intercept the next on-track feature, then make another small adjustment to have yourself running on track.

While I have been practicing for my nav test, I  have learnt to either fly a heading OR proceed visually. I am tempted to half fly a heading and twist it a bit to make up for unexpected winds.

the advantage of flying a heading and then correcting it is that you can fly a/the second more difficult half of your trip with more accuracy.

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Just now, APenNameAndThatA said:

While I have been practicing for my nav test, I  have learnt to either fly a heading OR proceed visually. I am tempted to half fly a heading and twist it a bit to make up for unexpected winds.

the advantage of flying a heading and then correcting it is that you can fly a/the second more difficult half of your trip with more accuracy.

You are best to do what your instructor taught, because that will be the basis for the Nav Test.

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On 07/01/2020 at 9:37 AM, old man emu said:

Another factor affecting off-track position is wind direction. If a pilot obtains the current weather before planning a flight, then the pilot will have a general idea of which side of the planned track the aircraft is likely to be blown to if the wind is greater or less than forecast. If a pilot is flying with a navigator (usually she who must be obeyed) the navigator can keep an eye on Track Made Good and advise heading corrections.

I find the grid point wind forecasts to often be complete fiction. Apparently that is because Archerfield is at the intersection of continental weather and maritime weather.

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2 minutes ago, turboplanner said:

You are best to do what your instructor taught, because that will be the basis for the Nav Test.

True, that.

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The more important thing is to make sure you expect checkpoints at the correct time. My great weakness is to look for them well before they can reasonably appear. Course corrections are relatively easy.

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7 hours ago, APenNameAndThatA said:

I find the grid point wind forecasts to often be complete fiction. Apparently that is because Archerfield is at the intersection of continental weather and maritime weather.

Windy will show that in a clear and easy to understand way. Those boxes full of numbers one gets from NAIPS to be legal are like somthing from 1950, before computer's were invented.

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The reality is that since GPS, all this real navigating is mainly for fun. Yes I know that the GPS might go down and we should be map-reading all the time too. But even maps are old hat now.

My son looked with horror at my maps one day and went out and bought me an iPad and Ozrunways. So now navigating consists of keeping the plane icon on the pink line. It's so easy it gives you time to worry about things like the CHT's.

The Ozrunways actually has the old Garmin \$200 yachting GPS as a backup, where you only needed to keep the line in the middle to fly direct to wherever, with clever "go to nearest " emergency provisions.

Actually,  there was a lot to like about the time when men were men and navigated by mathematics and maps and compass. They would arrive to be admired by simpering women. I always wanted a simpering woman.

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41 minutes ago, Bruce Tuncks said:

The reality is that since GPS, all this real navigating is mainly for fun. Yes I know that the GPS might go down and we should be map-reading all the time too. But even maps are old hat now.

My son looked with horror at my maps one day and went out and bought me an iPad and Ozrunways. So now navigating consists of keeping the plane icon on the pink line. It's so easy it gives you time to worry about things like the CHT's.

The Ozrunways actually has the old Garmin \$200 yachting GPS as a backup, where you only needed to keep the line in the middle to fly direct to wherever, with clever "go to nearest " emergency provisions.

Actually,  there was a lot to like about the time when men were men and navigated by mathematics and maps and compass. They would arrive to be admired by simpering women. I always wanted a simpering woman.

Anyone who has qualified for a Pilot Certificate or Pilot Licence will, or should have, demonstrated safe, manual, navigation, so no one should be forced into a Precautionary Landing, right?

And that possibility is quite likely with the quality level of GPS instruments we use today; I've read several pilot reports where the primary gps went down, the backup couldn't be made to work, and even one report where the primary failed, the secondary failed and third was being carried but had a flat battery. And then there's the situation where you are in turbulence, the country is featureless, but you haven't been worried about that to keep a record of your last fix (or probably never keep one), and under that stress you are trying to get a back up GPS out of a briefcase, only to drop it on the floor/find out you forgot the cable/realise you have nothing in the aircraft to plug it into etc.

As Pilot in Command you've put yourself in a position where you may experience a fuel exhaustion before you find an airfield just by flying around.

And as we've seen on another post, without doing something very simple, like marking your 10 minute intervals on your track, whether you're flying around storms or not, you also can't give an immediate endurance fuel time if ATC try to help you, and you're more likely to fall victim to some of the vagaries of aircraft fuel systems.

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If society grows more and more computerized, what happens if human beings forget how to do simple arithmetic? Back in 1957, Isaac Asimov, American author and biochemist, a highly successful and prolific writer of science fiction and of science books for the layperson, addressed this very question in a short story titled "The Feeling of Power". https://themathlab.com/writings/short stories/feeling.htm

The first part of the story is applicable to this current discussion, unfortunately Asimov was writing in the USA during the Cold War, so the ending is predictable in light of the war paranoia of the USA.

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Humans have repeatedly lost knowledge throughout their history. We're down to a tiny number of people who can operate a steam engine today.

I'd recommend the book "We the Navigators to everyone that flies" it gives the very basics, even before the arithmetic.

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The sad part, is we are raising young adults today who can't count, don't know their times tables, can barely spell, who think txting is proper English, and who need to have electronic devices in front of them constantly - such as tills that tell them the correct change to give. A power blackout or a flat battery is the ultimate hell for them.

I bought a lotto the other day, it was \$12.10, I handed the pretty 17 yr old girl the correct amount in cash in the form of a \$5 note and the rest in gold and silver coins - and she was absolutely and totally flummoxed, trying to add up how much there was in her hand. She had about 3 goes before she decided it might be correct, and put the money in the till tray, but she still had a look of total confusion on her face.

I'm guessing she'll end up an important financial controller for a huge organisation, where everyone with some maths skills will cover for her.

I have found that with the advent of electronic devices doing everything for us, you rapidly lose the important basic skills you were taught in primary school.

I now keep a handwritten daily diary (as I did in many previous years), to ensure my handwriting skills don't deteriorate. I often do longhand calculations and rows of additions mentally, to keep up my mental calculation skills.

The old adage still applies - use it, or lose it.

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But use it on something worthwhile. When you ACTUALLY MAKE something , you can SEE  the product of your labours.That beats just BUYING something you imagine you want or will show people how successful you are (appearing to be).  People buy the Car that  impresses others instead of the VEHICLE that might do the job the best or be the least cost, leaving money for AEROPLANES if you are an addict. Nev

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17 minutes ago, facthunter said:

But use it on something worthwhile. When you ACTUALLY MAKE something , you can SEE  the product of your labours.That beats just BUYING something you imagine you want or will show people how successful you are (appearing to be).  People buy the Car that  impresses others instead of the VEHICLE that might do the job the best or be the least cost, leaving money for AEROPLANES if you are an addict. Nev

How this comment applies to Ham Radio is amazing. When we actually built our own gear and got it on air - what a thrill that was. Now you buy the gear from China and get on air but hardly know how the stuff works and still think 'skip' is something the radio has. The dumbing down of society is such a crime.

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1 hour ago, onetrack said:

The sad part, is we are raising young adults today who can't count, don't know their times tables, can barely spell, who think txting is proper English, and who need to have electronic devices in front of them constantly - such as tills that tell them the correct change to give. A power blackout or a flat battery is the ultimate hell for them.

I bought a lotto the other day, it was \$12.10, I handed the pretty 17 yr old girl the correct amount in cash in the form of a \$5 note and the rest in gold and silver coins - and she was absolutely and totally flummoxed, trying to add up how much there was in her hand. She had about 3 goes before she decided it might be correct, and put the money in the till tray, but she still had a look of total confusion on her face.

I'm guessing she'll end up an important financial controller for a huge organisation, where everyone with some maths skills will cover for her.

I have found that with the advent of electronic devices doing everything for us, you rapidly lose the important basic skills you were taught in primary school.

I now keep a handwritten daily diary (as I did in many previous years), to ensure my handwriting skills don't deteriorate. I often do longhand calculations and rows of additions mentally, to keep up my mental calculation skills.

The old adage still applies - use it, or lose it.

Have a look at this link

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I'm dyslexic with numbers .

Bernie .

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23 hours ago, onetrack said:

The sad part, is we are raising young adults today who can't count, don't know their times tables, can barely spell, who think txting is proper English, and who need to have electronic devices in front of them constantly...

Saw a new ad on TV last night. Parents with a couple of young kids towing a big caravan. They arrive wherever they were going and the young boy, who has been playing with his electronic games gizmo in the car on the way up hops out. A bored looking young girl already at the campsite looks enviously at the gadget in his hand and next minute she has the spare hand controller and they are both playing this interactive game - which of course was the point of the ad - to show that you can play this game even when camping  I thought it was a bit sad. When we took our kids camping, the whole point was being in the bush or at the beach.

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It's a grievous disconnect from reality. To spend time in the bush is essential. to connect with the planet. Nev

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It makes no sense not to avail ourselves of the modern technology when flying. The aim isn't to navigate, it is to get where you want to go. For god's sake just use the GPS and get there while having time to look outside and monitor the engine and fuel. You'd be surprised how much traffic there can be.

As to GPS failing, if the satellites all go down you have larger problems than getting lost. WW3 just started.

Carry more than one unit with charged batteries and running off the aircraft power. I've got a Lowrance 2000C in the panel, 2 iPad minis running AvPlan and my Samsung J2 phone also runs AvPlan (the latest Android full version - it's great). Backups should be hot spares i.e running and visible to you. AvPlan shares the flight plan so it's on both iPads and the Lowrance has the next waypoint or destination up. Even airliners have only 2 engines nowadays.

A lot of the modern devices use not only GPS but Glonass, Beidou (about to be a complete global system but great in Australia) and Galileo. There's also a GPS compatible system of 4 QZSS satellites run by Japan. Also great in Australia. Right now I have 37 GNSS satellites in view from 5 different constellations plus 5 SBAS satellites which are also GPS L1 locators.

We have a problem in aviation, actually finding people who want to fly and willing to jump through the hoops to do so. Making them jump through WW 2 hoops for a PPL test is ridiculous. Nobody flies that way nowadays. What ever happened to train like you'll fly and fly like you trained?

If you want to postulate backups when everything fails are you going to train to flap your arms if the wings fall off? The navigation backup is pilotage, right Bruce? Before GPS when we were flying long distances out of Gawler in our gliders, a WAC chart with range rings around Gawler for final glides and simply looking at the ground meant we were never lost and always knew where to go next.

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I don't fully agree...I don't have or know how to use all this electronic stuff you speak of .

I do have a GPS in my car..I was trained to us the maps and eye sight while flying..being dyslexic doesn't help with electronic gizmos..NOT all can count .But I still received a flying certificate and can navigate .

Bernie .

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Agree with Mike the 1in60 has had it's day, even in light turbulence without a directional gyro nobody can fly a heading with enough accuracy to make it worthwhile. We nearly all use GPS now so our job shifts to monitoring and situational awareness, is the GPS showing credible information. I get just as much satisfaction doing this as flying in the good old days pre GPS.

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17 hours ago, Mike Borgelt said:

It makes no sense not to avail ourselves of the modern technology when flying.

Mike I both agree and disagree with your sentiments, I fly with every electronic gizmo that I can take with me and I'm also able to navigate manually if required. The biggest problem with totally relying on the electronic is that a lot of pilots (GA & RA) don't actually know where they are in relation to a point on the ground, VFR flying is being able to navigate with visual reference to the ground at all times or if you are on top of 8/8 cloud every 30 minutes you must be able to fix your position positively with a navigation aid that you have been trained in with the appropriate log book entry saying that you have been trained and you are proficient. I know this all seems pretty archaic but that is how it is.

The issue with the sentiments in this discussion is that RAA is trying to get access to CTA and to get that access you will need to be able to fly visually without any electronic equipment to the tolerances 100' either side of an assigned altitude and within 1 nm either side of track by looking out the window and referring to your flight plan and map.

Here is what scares me, we had a senior RA instructor from a very well known school on the sunny coast come to our club to upgrade to a CPL he had well more than the required 200 hours to sit the flight test and had completed the CPL theory but sensibly wanted to do some additional training and the test in the 210, interestingly enough a CPL is a day VFR licence and during your test you are not allowed to use any electronic devices you must do the test with the manual nav methods (I don't agree with it but that is the way it is), tracking through Amberly on his way to the Gold Coast he was asked to track to a position by ATC to avoid potential conflicting traffic he mis-identified his position turned left instead of right ended up 2 miles off track and failed the test. Now there are any number of things he could have done one being asking ATC for a vector.

Do I think the rules should be changed yes I do but I can't change them.

Everyone needs to remember even though you say well I'm not a commercial pilot so I don't need to do that we all share the same airspace below 10,000 and it doesn't matter how big or fast you are if you run into someone the results will be the same.

Aldo

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