Help with 1 in 60 rule
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Help with 1 in 60 rule
I'm seriously confused right now with track error and heading correction questions using the 1:60 rule,i have no idea when to use just the last part of the equation (dist off/dist to go) and when to use both parts,its probably really simple but I'm just not grasping the concept.Can someone please explain this to me,help would be much appreciated!
Not sure of the equation you use (I'm not very mathematically gifted).. but here's how I use the 1 in 60:
Firstly, determine the Initial Track Error, and correct for it. This will then have you paralleling your intended track.
Now determine the amount of distance remaining to your desired position where you wish to join your original track. If this is the remainder of distance to your destination, then so be it.
Figure the angle required to rejoin, and then add/subtrack that as well. Voila !!
eg. 100 mile leg, heading 090. After 60 miles you are 6 miles right of your track. That's 6 degrees in error, and in this case, subtracting 6 degrees from 090 = 084. Now this will parallel you to your track, and NOT get you back onto it...
Now there's 40 miles remaining to your turnpoint, and you are still 6 miles off course. I make that an extra 9 degrees adjustment, to arrive at the turnpoint. 084 - 9 = 075
Does that work for you?
PS. No slur intended on Pitts flyers Navigation technique...
Firstly, determine the Initial Track Error, and correct for it. This will then have you paralleling your intended track.
Now determine the amount of distance remaining to your desired position where you wish to join your original track. If this is the remainder of distance to your destination, then so be it.
Figure the angle required to rejoin, and then add/subtrack that as well. Voila !!
eg. 100 mile leg, heading 090. After 60 miles you are 6 miles right of your track. That's 6 degrees in error, and in this case, subtracting 6 degrees from 090 = 084. Now this will parallel you to your track, and NOT get you back onto it...
Now there's 40 miles remaining to your turnpoint, and you are still 6 miles off course. I make that an extra 9 degrees adjustment, to arrive at the turnpoint. 084 - 9 = 075
Does that work for you?
PS. No slur intended on Pitts flyers Navigation technique...
Last edited by Runaway Gun; 16th Oct 2007 at 17:12. Reason: Pretty Picture added
I hope that answers your question....
Track Error: 6 degrees
Correction: 15 degrees
It took me hours to draw that picture. Is it right?
Track Error: 6 degrees
Correction: 15 degrees
It took me hours to draw that picture. Is it right?
Think of it as two different problems: The first problem is how to correct a track that is drifting from the Desired Track so that it is no longer deviating ie parallels the Desired Track. The second problem is how to correct a track that is parallel to the desired track ie the Heading is correct but the aircraft's position is offset from some point on the Desired Track where you'd like it to be.
First problem: Stopping the drift away from track. Use Distance Run from where you last paralleled track (usually the last point you were happily proceeding along that desired/planned track). Turn towards the Desired Track by however many degrees you get from this 1st part of the 1:60 method.
Second problem: You've successfully stopped any further drift and now wish to regain track. Use Distance to Go to whatever the position is on the Desired Track that you'd like to regain track. Turn towards track by however many degrees this 2nd part gives you. **Don't forget to remove this second Heading adjustment - but not the first adjustment - once you've regained track**
Note that you don't have to do both parts at the same time. You could solve Part One only so that you parallel track for a while, and then, some time later, do Part Two to regain track. Usually, however, both parallel & close track problems are done together to save buggerising around twice. After all, the only difference is whether you use Dist Run or Dist to Go, respectively.
First problem: Stopping the drift away from track. Use Distance Run from where you last paralleled track (usually the last point you were happily proceeding along that desired/planned track). Turn towards the Desired Track by however many degrees you get from this 1st part of the 1:60 method.
Second problem: You've successfully stopped any further drift and now wish to regain track. Use Distance to Go to whatever the position is on the Desired Track that you'd like to regain track. Turn towards track by however many degrees this 2nd part gives you. **Don't forget to remove this second Heading adjustment - but not the first adjustment - once you've regained track**
Note that you don't have to do both parts at the same time. You could solve Part One only so that you parallel track for a while, and then, some time later, do Part Two to regain track. Usually, however, both parallel & close track problems are done together to save buggerising around twice. After all, the only difference is whether you use Dist Run or Dist to Go, respectively.
Runaway Gun's explanation seems to be the solution that will get you to the turning point. I remember learning this in RAF flying training in the mid 80s and it was known as the New Track Reference method. The disadvantages were that it took a while to calculate and second, it did exactly what it says on the box and gave you a new track. Often, regaining track was the best policy for several reasons.
A few years later, when I became an instructor, I was pleased to see the NTR method ditched in favour of the Standard Closing Angle technique. Based simply on the 1 in 60 rule, you applied an angle (the SCA) to regain track and flew this new heading for as many minutes as you were miles off track. The angle you flew was based on your groundspeed. At 60 knts, you flew 60 degrees (1 in 60), 120 knts = 30 degrees, 240 knots = 15 degrees, 300 knts, = 12 degrees, 420 knts = 7 degrees. Its basicly 60 divided by as many miles a minute you are doing.
So at 90 knots, your standard closing angle would be 40 degrees (60 divided by 1.5). If on a heading of 360, at a check point you noticed you were 2 miles right of track, if you steer 320 for 2 minutes then come back onto your original heading, you will be back on track. As Tinstaffl mentions, you do have to apply a correction to prevent it happening again. Decide whether was it a once only error (avoiding weather/inaccurate flying) which means no correction, or a persistant error (wrong drift applied/wind different to forecast) then a correction is required.
The advantages of this method is that it's simple, easy to apply and quick - as you will have worked out the SCA for your speed at the planning stage. Once you have recognised you are off track, the calculation can be made in seconds and applied immediately - and you have the added benefit of regaining track with all the attendant advantages. The disadvantages are that the heading change can be a bit extreme with problems if you miss the time you need to turn back onto track, and the gound track increases a bit with a resultant change in the timing for the leg. To alleviate thes problems, you can change the values slightly. On one type I instructed on which flew at 90 knts on NAVEXes, we used 20 degrees for 2 minutes per mile off track.
It works very well, and it's suited to the high workload low level
environment in military flying and the PPL sunday afternoon trip to another airfield for tea and stickies alike. And it's well within the parameters of the KISS (Keep It Simple Stupid) philosophy I like to apply to my working life!
A few years later, when I became an instructor, I was pleased to see the NTR method ditched in favour of the Standard Closing Angle technique. Based simply on the 1 in 60 rule, you applied an angle (the SCA) to regain track and flew this new heading for as many minutes as you were miles off track. The angle you flew was based on your groundspeed. At 60 knts, you flew 60 degrees (1 in 60), 120 knts = 30 degrees, 240 knots = 15 degrees, 300 knts, = 12 degrees, 420 knts = 7 degrees. Its basicly 60 divided by as many miles a minute you are doing.
So at 90 knots, your standard closing angle would be 40 degrees (60 divided by 1.5). If on a heading of 360, at a check point you noticed you were 2 miles right of track, if you steer 320 for 2 minutes then come back onto your original heading, you will be back on track. As Tinstaffl mentions, you do have to apply a correction to prevent it happening again. Decide whether was it a once only error (avoiding weather/inaccurate flying) which means no correction, or a persistant error (wrong drift applied/wind different to forecast) then a correction is required.
The advantages of this method is that it's simple, easy to apply and quick - as you will have worked out the SCA for your speed at the planning stage. Once you have recognised you are off track, the calculation can be made in seconds and applied immediately - and you have the added benefit of regaining track with all the attendant advantages. The disadvantages are that the heading change can be a bit extreme with problems if you miss the time you need to turn back onto track, and the gound track increases a bit with a resultant change in the timing for the leg. To alleviate thes problems, you can change the values slightly. On one type I instructed on which flew at 90 knts on NAVEXes, we used 20 degrees for 2 minutes per mile off track.
It works very well, and it's suited to the high workload low level
environment in military flying and the PPL sunday afternoon trip to another airfield for tea and stickies alike. And it's well within the parameters of the KISS (Keep It Simple Stupid) philosophy I like to apply to my working life!
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Or another way to do it is to use Runaway guns technique but only make the correction at the mid point. That way the correction is always twice the angle.With 10 degree drift lines students seem to be able to work out how many degrees they are off track. (if you have long legs split them up into 50-60 mile lengths)
Then if you are 6 degrees off the correction is 12 degrees. If you are 4 degrees off the correction is 8 degrees.
I've nothing against SCA (whichever floats your boat and it works). With the SCA method you need to know how many miles you are off to apply the sca then determine your closing heading , then apply the new track. And how do you know when you have regained track.
(but that doesn't help you answer the CAAs questions)
Then if you are 6 degrees off the correction is 12 degrees. If you are 4 degrees off the correction is 8 degrees.
I've nothing against SCA (whichever floats your boat and it works). With the SCA method you need to know how many miles you are off to apply the sca then determine your closing heading , then apply the new track. And how do you know when you have regained track.
(but that doesn't help you answer the CAAs questions)
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Thanks for the replies and diagrams guys.It's sort of made things clearer,I did some practice questions and it seems that i was basically confusing myself with something reletively simple,the key words seem to be track or hdg in these questions.
These are two that i attempted,can you guys just confirm I'm right:
*An aircraft is flying from A to B, distance 212 nm. After flying 135 nm the aircraft is 9 nm Left of track. The alteration of heading to fly to B is
* An aircraft is flying from C to D. track 270(T). distance 345 nm. After flying 135 nm the aircraft is 14 nm Left of track. The new track to D is
These are two that i attempted,can you guys just confirm I'm right:
*An aircraft is flying from A to B, distance 212 nm. After flying 135 nm the aircraft is 9 nm Left of track. The alteration of heading to fly to B is
Answer: 11 degrees,the sum of the track error and second part of the equation as we want total heading alternation to reach B
* An aircraft is flying from C to D. track 270(T). distance 345 nm. After flying 135 nm the aircraft is 14 nm Left of track. The new track to D is
Answer: 274(T) ,this time we would only use the second part of the equation as we want the new track to D,so 270+ 4
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First answer correct.
Second answer - why are you applying only the closing angle? This is not allowing for the incorrect wind that blew you off track (which is the assumption here).
Off course the real correct answer is that you should have picked up and corrected the track error a long time before getting to 135 nmls
Second answer - why are you applying only the closing angle? This is not allowing for the incorrect wind that blew you off track (which is the assumption here).
Off course the real correct answer is that you should have picked up and corrected the track error a long time before getting to 135 nmls
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Originally Posted by foxmouth
Second answer - why are you applying only the closing angle? This is not allowing for the incorrect wind that blew you off track (which is the assumption here).
Quote 18 greens: "I've nothing against SCA (whichever floats your boat and it works). With the SCA method you need to know how many miles you are off to apply the sca then determine your closing heading , then apply the new track. And how do you know when you have regained track."
1. To find out how many miles off track you are, you refer to your map and estimate. You will probably be within a mile, which means you should see your turning point when you get to it.
2. The closing heading will always be the same. If you've planned at 120 knots, it will be 30 degrees off from your originally planned heading. The amount of time you fly this heading is the variable and this depends on you off track estimate.
3. How do you know when your on track again? You trust the method. You turn back onto your original heading (with a suitable correction if you consider the error to be persistant) when you have reached the time to do so. This will probably be without reference to the map. If you apply the technique accurately, you will be back on track, or certainly close enough to find your next check/turning point.
The technique works. It's simple geometry and what's more, it's very easy to apply. I was learnt the technique while a pilot in the RAF and tought it to my PPL students subsequently. Some of the techniques the students had been taught previously to regain track or fly direct to the TP ranged from the mildly confusing to the completely baffling, and from interesting to astounding. Getting out your nav rule, protractor and whizz wheel while attempting to fly accurately and look out is not a practical option in my opinion. Without exception, those I showed the SCA to agreed that it was the best method by far.
1. To find out how many miles off track you are, you refer to your map and estimate. You will probably be within a mile, which means you should see your turning point when you get to it.
2. The closing heading will always be the same. If you've planned at 120 knots, it will be 30 degrees off from your originally planned heading. The amount of time you fly this heading is the variable and this depends on you off track estimate.
3. How do you know when your on track again? You trust the method. You turn back onto your original heading (with a suitable correction if you consider the error to be persistant) when you have reached the time to do so. This will probably be without reference to the map. If you apply the technique accurately, you will be back on track, or certainly close enough to find your next check/turning point.
The technique works. It's simple geometry and what's more, it's very easy to apply. I was learnt the technique while a pilot in the RAF and tought it to my PPL students subsequently. Some of the techniques the students had been taught previously to regain track or fly direct to the TP ranged from the mildly confusing to the completely baffling, and from interesting to astounding. Getting out your nav rule, protractor and whizz wheel while attempting to fly accurately and look out is not a practical option in my opinion. Without exception, those I showed the SCA to agreed that it was the best method by far.
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You never know when you might need the 1/60 rule. Today I was cutting edge trims for the front door of my narrowboat, not a right angle on it, but by extending one edge with a rule for 6" and measuring the gap, I then had the angle needed to set on my mitre saw!
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Going back to the brilliant diagram of 'Runaway Gun', the first Blue track could be a curve due to increasing precession of the DI gyro. So where do you reset the DI to Compass? and will this not upset the correction heading angles required? as you will also need to add or subtract this DI/Compass error.
Theory is Ok in some academic cases, but has its limitations in practice. (The cross-wind can alter from Start to Finish.)
Theory is Ok in some academic cases, but has its limitations in practice. (The cross-wind can alter from Start to Finish.)
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What a waste of time....learning all that then never using it in anger. Very usefull over the sea.....Scenario
take off from Bournemouth en-route Jersey look at magenta line on gps, work out angle to regain track apply that until back on magenta line. I get it now.
take off from Bournemouth en-route Jersey look at magenta line on gps, work out angle to regain track apply that until back on magenta line. I get it now.
Last edited by PA28181; 18th Nov 2014 at 10:23.
Avoid imitations
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Phiggs,
The technique assumes the DI is synchronised with the mag compass (common sense says it should always be so)! If the DI wasn't synchronised at the time of discovering the track error, it must be corrected before trying to fly on it any further.
It matters not how you got the track error in the first place, it's merely a rule of thumb to regain track.
The technique assumes the DI is synchronised with the mag compass (common sense says it should always be so)! If the DI wasn't synchronised at the time of discovering the track error, it must be corrected before trying to fly on it any further.
It matters not how you got the track error in the first place, it's merely a rule of thumb to regain track.
Dan,
I hadn't heard of the SCA technique before. Very nice. Much more practical than the NTR method I was taught in my Chipmunk days.
Thanks.
I hadn't heard of the SCA technique before. Very nice. Much more practical than the NTR method I was taught in my Chipmunk days.
Thanks.
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If you're six miles off track after flying 60 miles
(a) where on earth do you find somewhere you can fly 100 miles in a straight line anyway without busting some airspace or other?
(b) how come you've spent the whole 60 miles not checking and correcting your position, so that you've only just discovered the problem?
(c) anyway, if you haven't been applying any corrective action then only being six miles off track after 60 miles is pretty good going
(d) and you can see some landmark or other that's on your original track - just point at it and fly until you get there!
(e) ... except of course if you can't see six miles you're almost certainly navigating by following needles and dials and magenta lines anyway, so you're still on your original track.
Pity these real-world answers don't get you the exam marks, isn't it.
(a) where on earth do you find somewhere you can fly 100 miles in a straight line anyway without busting some airspace or other?
(b) how come you've spent the whole 60 miles not checking and correcting your position, so that you've only just discovered the problem?
(c) anyway, if you haven't been applying any corrective action then only being six miles off track after 60 miles is pretty good going
(d) and you can see some landmark or other that's on your original track - just point at it and fly until you get there!
(e) ... except of course if you can't see six miles you're almost certainly navigating by following needles and dials and magenta lines anyway, so you're still on your original track.
Pity these real-world answers don't get you the exam marks, isn't it.
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Can't get to sleep so tried SkyDemonLite for a 100 mile straight line.
How about Gloucester to Kings Lynn at 104 nm. Crosses no ATZ or MATZ, and nothing to bust below 4500
Chris
How about Gloucester to Kings Lynn at 104 nm. Crosses no ATZ or MATZ, and nothing to bust below 4500
Chris
Gertrude, despite being a wombat you've apparently never been to Australia.
If you choose the right area you can fly hundreds of miles in a straight line there without busting airspace.
And you could easily fly 60 miles without seeing any obvious landmark by which to fix your position.
If you choose the right area you can fly hundreds of miles in a straight line there without busting airspace.
And you could easily fly 60 miles without seeing any obvious landmark by which to fix your position.