DME arc

Blip16

Blip16

Well-Known Member
normally i teach "turn 10, twist 10" with the VOR. I have this student who refuses to use it. all he will do is track to the station on some sort of radial (not the right one, we got yelled at by his approach buddies because he did that) and then once he gets on the 12 dme arc, he will just use that to maintain the arc. it worked for him today, but it is not how i want him to fly it.

there are some other issues at work here as well, mainly stemming from the fact he is an approach controller and therefore he knows more about the IFR system than me, that is something else i am trying to work on, but it is tough.


anyway, was the way he flew the arc today a way to fly it, i mean it did work, and if it is acceptable than i will let him do it, although i had no idea of his intentions since he refuses to let me know what his plans are for the approach (won't do an approach brief)
 
Remember, the whole goal is to maintain the distance and then track inbound/outbound on the correct radial. The turn 10 twist 10 is nothing more than a teaching aid to help visualize what you are doing, it isn't a "required" manuever.

I usually fly a DME arc in a constant (or nearly constant) turn, ie a slight amount of bank all the way around, and just use the distance and GS read out from the DME to maintain the ARC.
 
Dugie8 said:
Remember, the whole goal is to maintain the distance and then track inbound/outbound on the correct radial. The turn 10 twist 10 is nothing more than a teaching aid to help visualize what you are doing, it isn't a "required" manuever.

I usually fly a DME arc in a constant (or nearly constant) turn, ie a slight amount of bank all the way around, and just use the distance and GS read out from the DME to maintain the ARC.
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sounds good to me, i do that too i guess, i do still update the vor though because then i have an idea of exactly when my course is coming up
 
That is why I loved the Bendix radio stacks. Pull the NAV knob out, voila, what radial you are on.
 
BuickCFI said:
sounds good to me, i do that too i guess, i do still update the vor though because then i have an idea of exactly when my course is coming up
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I update the VOR also as a guide to situational awareness, but it is not a turn 10, twist 10.

As Dugie said, 10/10 is a teaching technique and one which IMO unnecessarily complicates a fairly simple procedure. The method I use is that I twist 10 after the turn on the arc as a cross-check that I turned the correct way :rolleyes: and then to various points along the arc.

On your student, I am not worried about your student's refusal to do the 10/10, but I am about his failure to brief the approach and describe what he is doing. Frankly I wouldn't put up with it.

Do you have access to a sim/FTD? If you do, have him fly the VOR/DME OR TACAN Z RWY 15 approach into MTN (current chart at http://naco.faa.gov/d-tpp/0706/05222VDTZ15.PDF) If he does it fine, you'll at least have a little more confidence in his ability even if he's not explaining what he is doing.
 
MidlifeFlyer said:
I update the VOR also as a guide to situational awareness, but it is not a turn 10, twist 10.

As Dugie said, 10/10 is a teaching technique and one which IMO unnecessarily complicates a fairly simple procedure. The method I use is that I twist 10 after the turn on the arc as a cross-check that I turned the correct way :rolleyes: and then to various points along the arc.

On your student, I am not worried about your student's refusal to do the 10/10, but I am about his failure to brief the approach and describe what he is doing. Frankly I wouldn't put up with it.

Do you have access to a sim/FTD? If you do, have him fly the VOR/DME OR TACAN Z RWY 15 approach into MTN (current chart at http://naco.faa.gov/d-tpp/0706/05222VDTZ15.PDF) If he does it fine, you'll at least have a little more confidence in his ability even if he's not explaining what he is doing.
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i wish i did have access to a sim FTD for him to use, thats an awesome approach i am going to save

Here is another question about the arc, if you don't have GPS are are cleared direct to SLOAF in the example you gave me, how to you fly direct there? I would intercept the 334 and track that to the point, or at least put in an intercept tha would bring be dang close and then track it in for the last few miles rather than maybe 10 miles. AFAIK that is how it would be done. My student yesterday went and created his own arc off of the established arc and then tracked to the point because he didn't want to listen to me because we might have screwed up the plan the controllers had, heaven forbid! So we ended up getting yelled at by his buddies on the radio.
I am going to start a new thread on the anti-authority to keep this about arcing
 
Dugie8 said:
Remember, the whole goal is to maintain the distance and then track inbound/outbound on the correct radial. The turn 10 twist 10 is nothing more than a teaching aid to help visualize what you are doing, it isn't a "required" manuever.

I usually fly a DME arc in a constant (or nearly constant) turn, ie a slight amount of bank all the way around, and just use the distance and GS read out from the DME to maintain the ARC.
Click to expand...

There was an article in "IFR Magazine" recently that recommended this very method as a means of reducing workload. I also was taught the twist 10/turn 10 method, but after reading the article I fired up the sim and gave it a try. I like it and could immediatly see the benefits of reduced workload. I update the radial every once in awhile to maintain SA, and as I approach the lead in radial I set that in the OBS so that I can turn in to the established course a couple of degrees before it centers (if applicable, obviously MidlifeFlyers great example is quite different than the typical DME arc appch).
 
BuickCFI said:
i wish i did have access to a sim FTD for him to use, thats an awesome approach i am going to save

Here is another question about the arc, if you don't have GPS are are cleared direct to SLOAF in the example you gave me, how to you fly direct there? I would intercept the 334 and track that to the point, or at least put in an intercept tha would bring be dang close and then track it in for the last few miles rather than maybe 10 miles. AFAIK that is how it would be done. My student yesterday went and created his own arc off of the established arc and then tracked to the point because he didn't want to listen to me because we might have screwed up the plan the controllers had, heaven forbid! So we ended up getting yelled at by his buddies on the radio.
I am going to start a new thread on the anti-authority to keep this about arcing
Click to expand...

There is a neat little trick you can use to go direct to just about any fix as long as you can define that fix with a radial/bearing and distance. Almost impossible to describe in words, very easy to show in person. Next time I am in GFK we should go for a "ride".
 
Dugie8 said:
There is a neat little trick you can use to go direct to just about any fix as long as you can define that fix with a radial/bearing and distance. Almost impossible to describe in words, very easy to show in person. Next time I am in GFK we should go for a "ride".
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that would be good
 
Dugie8 said:
There is a neat little trick you can use to go direct to just about any fix as long as you can define that fix with a radial/bearing and distance. Almost impossible to describe in words, very easy to show in person. Next time I am in GFK we should go for a "ride".
Click to expand...


Hey Dugie, does that trick use just the OBS, or do you need a bearing pointer? I know a method to do just what you are talking about (direct to a radial/DME fix) but it uses a bearing pointer.

As for arcing, I teach in aircraft that have bearing pointers, and the technique I teach is to keep the bearing pointer at the 90 degree index. If you get a little bit off the arc, place the bearing pointer above or below the 90 index. (5 degrees below the 90 index for every 1/2 mile inside the arc, or 10 degrees above the index for every 1/2 mile outside the arc.)
 
fish314 said:
Hey Dugie, does that trick use just the OBS, or do you need a bearing pointer? I know a method to do just what you are talking about (direct to a radial/DME fix) but it uses a bearing pointer.

As for arcing, I teach in aircraft that have bearing pointers, and the technique I teach is to keep the bearing pointer at the 90 degree index. If you get a little bit off the arc, place the bearing pointer above or below the 90 index. (5 degrees below the 90 index for every 1/2 mile inside the arc, or 10 degrees above the index for every 1/2 mile outside the arc.)
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You need an RMI (well to make it easy). You take your index and middle finger and with the middle finger put it on the middle of the RMI, your index finger is the distance. So if you are 30 miles from the VOR from the middle of the RMI to the top of the case is 30 miles. Now you know the radial and bearing of your fix (say 180 at 15), you take the (V) shape you have made with your fingers and you "slide" that V to either the 360 or 180 (this takes some SA). This will give you the heading to fly (corrected for wind if you are tracking a straight line to the station already) and the distance to fly (you can use your MACH for NM/M, ie .4 mach is 4 miles per minute) and you can fly directly to that fix and know how long it will take to get there.
 
Dugie8 said:
You need an RMI (well to make it easy). You take your index and middle finger and with the middle finger put it on the middle of the RMI, your index finger is the distance. So if you are 30 miles from the VOR from the middle of the RMI to the top of the case is 30 miles. Now you know the radial and bearing of your fix (say 180 at 15), you take the (V) shape you have made with your fingers and you "slide" that V to either the 360 or 180 (this takes some SA). This will give you the heading to fly (corrected for wind if you are tracking a straight line to the station already) and the distance to fly (you can use your MACH for NM/M, ie .4 mach is 4 miles per minute) and you can fly directly to that fix and know how long it will take to get there.
Click to expand...


Ok, yeah, that's exactly the same method I use basically, for getting a heading. I never thought about how to estimate the distance to go/time to go, but that makes sense also. I'm going to start using that! Thanks.
 
Dugie8 said:
You need an RMI (well to make it easy). You take your index and middle finger and with the middle finger put it on the middle of the RMI, your index finger is the distance. So if you are 30 miles from the VOR from the middle of the RMI to the top of the case is 30 miles. Now you know the radial and bearing of your fix (say 180 at 15), you take the (V) shape you have made with your fingers and you "slide" that V to either the 360 or 180 (this takes some SA). This will give you the heading to fly (corrected for wind if you are tracking a straight line to the station already) and the distance to fly (you can use your MACH for NM/M, ie .4 mach is 4 miles per minute) and you can fly directly to that fix and know how long it will take to get there.
Click to expand...
if i was instructing in the WARG i could use that, but nothing i fly has an RMI
 
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