DME arcs - why the bad rap?

[nddons]

I've always heard that DME arcs are difficult. Tonight I flew my first DME arcs with my CFII. Compared to holding over fixes with a single VOR, or mastering NDBs (can anyone do that?), DME arcs didn't seem too tough. Granted, I had an HSI which seemed to help visualize the geometry, and learned that things really speed up in 5 DME arcs vs. 10 DME arcs, especially with a wind, but they didn't seem all that complicated to understand or difficult to execute.

Am I missing something?

On a related note, I really enjoy having my instrument lessons at night. Besides the smooth and cool air, it seems to really feel more like actual instrument conditions when under the hood, as there are no tel-tale shadows in the cockpit, or the benefit of an occasional cheating glance out the corner of the hood. My night landings have even improved, though that's tough with only one landing per flight.

 

[sba55]

I like DME arcs, too. As long as you don't turn the wrong way, they're easy.

Just like you, I had almost all my instrument lessons at night. Less traffic, not as much terrain to look at, and everybody is nicer at night, anyways. Good luck with the remainder of your IFR training!

-Felix

 

[KennyFlys]

Are you doing the "Twist ten, Turn ten" on the VOR needle and DME readout or GPS distance? Or, is it a GPS overlay? The former is really pretty easy if one is patient with the turns and watches the trend followed by the small change it really is.

The latter... is cheating.

On your approaches, they are probably giving you the option and you make a low approach. Just ask for a touch-n-go on each approach so you can get the practice and log the night landing. That shouldn't add more than a few minute to your flight time.

 

[midlifeflyer]

DME arcs tend to be easier to fly than to explain, and less complicated to explain than the usual way of explaining them. On top of that, there aren't that many around and many pilots go through instrument training without flying even one. Those who try to uinderstand them without doing them end up with the impression that they are complicated and difficult.

Turn the correct way when you intercept the arc, keep the DME readout in the ballpark, periodically track your way around for spatial orientation, and turn inbound at the appropriate time to intercept the FAC.

Really pretty easy.

 

[ScottM]

They are no big deal, way better to fly than holds. My biggest complaint about them is I do not practice them very much so I hav eot go through a lot of mental gymnastics to re-learn then as I go.

 

[vontresc]

Uhmmm Kenny those won't count towards night currency though if they are touch and goes.

On your approaches, they are probably giving you the option and you make a low approach. Just ask for a touch-n-go on each approach so you can get the practice and log the night landing. That shouldn't add more than a few minute to your flight time.

But I am assuming you already know of 61.57(b)

(b) Night takeoff and landing experience. (1) Except as provided in paragraph (e) of this section, no person may act as pilot in command of an aircraft carrying passengers during the period beginning 1 hour after sunset and ending 1 hour before sunrise, unless within the preceding 90 days that person has made at least three takeoffs and three landings to a full stop during the period beginning 1 hour after sunset and ending 1 hour before sunrise

 

[KennyFlys]

Uhmmm Kenny those won't count towards night currency though if they are touch and goes.

But I am assuming you already know of 61.57(b)

For night currency, nope. But, they will fit in nicely on the 8710 in Block III to help that night landing number. As long as you touched deck, they qualify for entry.

 

[ApacheBob]

In 19 years, I have never issued a DME arc. I would love to. It sounds so retro. I have never issued a cruise clearance, either. I would like to have flown one of the "colored" airways in North Carolina. I am pretty sure that they have all been decomissioned. Do you know?
ApacheBob

 

[Everskyward]

In 19 years, I have never issued a DME arc.

You ought to transfer to Denver Center and work the sector which includes KRIL. I've gotten that one a number of times.

 

[nddons]

Are you doing the "Twist ten, Turn ten" on the VOR needle and DME readout or GPS distance? Or, is it a GPS overlay? The former is really pretty easy if one is patient with the turns and watches the trend followed by the small change it really is.

The latter... is cheating.

On your approaches, they are probably giving you the option and you make a low approach. Just ask for a touch-n-go on each approach so you can get the practice and log the night landing. That shouldn't add more than a few minute to your flight time.

No, this is in a 172R, so it's twist 10 turn 10. It has an HSI, but my CFII also had me tune the VOR into NAV 2 to see it presented differently than on the HSI. I use the GPS only for DME info as it's a Bendix/King 89 or some other model of GPS dinosaur.

The tower closes at 0300Z so it's Class G when we land.

 

[MauleSkinner]

I never figured out the "twist ten, turn ten" thing...to me, it's a DME arc, so you fly the arc using DME until your lead-in centers or your final approach course comes live. The VOR is always off your left wingtip, give or take, for left-turning arcs, and off your right wingtip for right-turning arcs.

Just as easy with a CDI as it is with HSI/RMI.

Fly safe!

David

 

[TMetzinger]

I just set the lead radial, watch the DME, and fly. DME increasing, tighten the turn. DME decreasing, shallow it.

Anyone who's gone around a New England Rotary at 3 AM to find the PERFECT steering wheel angle will have no problem with DME arcs.

 

[CJones]

Tony and I did this one during my IR training. It was a hoot. You had to stay on your toes a bit, but wasn't too bad. I think it brought up a conversation (we had a STIFF headwind on final, so we had time to burn) about doing an BC approach while inverted - which way would you turn to keep the needle centered - away from or towards the needle?

http://204.108.4.16/d-tpp/0809/00667LBC18.PDF

 

[midlifeflyer]

I never figured out the "twist ten, turn ten" thing...to me, it's a DME arc, so you fly the arc using DME until your lead-in centers or your final approach course comes live. The VOR is always off your left wingtip, give or take, for left-turning arcs, and off your right wingtip for right-turning arcs.

Just as easy with a CDI as it is with HSI/RMI.

Fly safe!

David

I agree, David. I always thought "twist 10 - turn 10" was a lot of extra unnecessary and artificial work. I think it is important to maintain situational awareness throughout the arc, but I think the twists can be limited to (1) the first 10-20° after interception as a cross-check that you turned the right way , (2) the lead radial (or reasonable facsimile thereof), and (3) such additional radials along the way as the pilot determines helps.

On (3) for example, I like knowing when I'm about halfway through. If the reported winds are strong, I may twist more often to check the speed of my progress as a way of staying ahead of the airplane.

 

[vontresc]

Hehe I remember when we got the 430w update, I decided to fly the now decommissioned SDF 36 into Fond du Lac, just to see what the roll steering would do with the DME Arc. I gotta say that a DME arc is stupid easy when you have a moving map as opposed to trying to visualize it, and trying to figure out wehter to add or subtract 100 degrees before blowing through the DME distance

 

[vontresc]

Ok now I looked at the replacemennt for the SDF the new LOC/DME 36 at Fond du lac.
http://204.108.4.16/d-tpp/0809/05231LD36.PDF
This plate has me a little confused. From what I can see there are 3 IAFs the DOYAG and ERAGE intersections, and the Badger VOR. All three are NoPT IAFs, so why is there a procedure turn depicted on the plate?

Secondly the missed procedure has me a bit confused. Exiting the hold there is a note "2800 to CADVU". Does this mean that once one is back on the loc at CADVU you can fly the PT? That's what I probably would do,but this plate is a bit odd.

Finallyy what is the significance of the GODEC IF? I am assuming that is where the feeder route drops you off, but I was wondering if there is any added significance.

Thanks

 

[nddons]

I agree, David. I always thought "twist 10 - turn 10" was a lot of extra unnecessary and artificial work. I think it is important to maintain situational awareness throughout the arc, but I think the twists can be limited to (1) the first 10-20° after interception as a cross-check that you turned the right way , (2) the lead radial (or reasonable facsimile thereof), and (3) such additional radials along the way as the pilot determines helps.

On (3) for example, I like knowing when I'm about halfway through. If the reported winds are strong, I may twist more often to check the speed of my progress as a way of staying ahead of the airplane.

But, but - you mean John and Martha are wrong?

Actually my CFII (a 9,000 hour former MD-80 captain) was doing it by the book, and his goal was for me to understand exactly which radial I'm on at any moment (or more precisely, what my NEXT radial will be), though I can see the simpler way of flying one.

 

[KennyFlys]

Ok now I looked at the replacemennt for the SDF the new LOC/DME 36 at Fond du lac.
http://204.108.4.16/d-tpp/0809/05231LD36.PDF
This plate has me a little confused. From what I can see there are 3 IAFs the DOYAG and ERAGE intersections, and the Badger VOR. All three are NoPT IAFs, so why is there a procedure turn depicted on the plate?

I looked up FDCs for this approach on WSI and none were found. Could OSH be an IAF that was not marked accordingly? The idea is to fly the backcourse of the localizer then reverse course at the PT?

So far, I can't get an answer locally.

Secondly the missed procedure has me a bit confused. Exiting the hold there is a note "2800 to CADVU". Does this mean that once one is back on the loc at CADVU you can fly the PT? That's what I probably would do,but this plate is a bit odd.

Where do you see 2800 on the missed? I'm seeing a straight climb to 2,000 then climbing left turn to 3,000 and direct OSH.

Finally what is the significance of the GODEC IF? I am assuming that is where the feeder route drops you off, but I was wondering if there is any added significance.

An Intermediate Fix to identify the 13.2 DME point on the localizer.

 

[midlifeflyer]

But, but - you mean John and Martha are wrong?

What can I say

Sometimes the standard way of teaching something actually makes it more difficult. That seems to be especially true for instrument training where DME arcs and even holds are far simpler than "the book" makes them out to be.

 

[flyingcheesehead]

This plate has me a little confused. From what I can see there are 3 IAFs the DOYAG and ERAGE intersections, and the Badger VOR. All three are NoPT IAFs, so why is there a procedure turn depicted on the plate?

There is a transition route marked from OSH to CADVU (2800, 168, 17.9). It looks like CADVU should be marked as an IAF.

Secondly the missed procedure has me a bit confused. Exiting the hold there is a note "2800 to CADVU". Does this mean that once one is back on the loc at CADVU you can fly the PT? That's what I probably would do,but this plate is a bit odd.

There's generally not any depiction of anything exiting a hold on an approach plate - That's just a transition route. Again, I think that CADVU should be marked as an IAF.

Finallyy what is the significance of the GODEC IF? I am assuming that is where the feeder route drops you off, but I was wondering if there is any added significance.

GODEC is the end of the transition route from BAE.

Oddly enough, looking at the various transition routes and such, by the markings on the plate it appears that CADVU and GODEC should both be marked as IAF's, and BAE should NOT be marked as an IAF. (Ever seen a transition route from an IAF before?)

Time to contact NACO...

 

[flyingcheesehead]

I agree, David. I always thought "twist 10 - turn 10" was a lot of extra unnecessary and artificial work. I think it is important to maintain situational awareness throughout the arc, but I think the twists can be limited to (1) the first 10-20° after interception as a cross-check that you turned the right way , (2) the lead radial (or reasonable facsimile thereof), and (3) such additional radials along the way as the pilot determines helps.

I like to keep twisting so as to maintain positive positional awareness throughout the arc. Maybe that's just because I'm impatient.

Stan, I think the DME arc may get a bad rap because there's no needle telling you what to do. In that way it's somewhat like an NDB approach - Mental work is required to know where you are in relation to the desired course. However, I never found DME arcs particularly difficult.

 

[MauleSkinner]

My biggest issue with the "turn 10, twist 10" philosophy is that you've got too much potential to screw up your lead-in radial if you've got one...Second biggest issue is for those of us who are willing to fly IFR with a single VOR receiver...too much chance to screw up the inbound course and/or ILS freq. IMO, the best time to set critical radials is when you're doing the setup ahead of time, when you've GOT time. Waiting until you're within 10 degrees of the lead-in offers too much opportunity for mis-setting the OBS. Or even missing the lead-in completely...I've seen that more than once, and it kinda screws up the rest of the approach.

I fly an "inside the arc" profile...say I'm flying a 15 DME arc. Make the initial turn onto the arc, read the DME, and if I'm outside 15 DME, take a 20-degree cut. If I'm inside the arc, hold heading. Eventually the DME stops counting down and starts counting up. When I hit 15 DME, take another 20 degrees. I'll get a couple of tenths outside, it'll start counting down, I'll get a few tenths inside, it'll start counting up. When I hit 15 DME again, take another 20 degrees. If I've got winds in excess of 20 knots across the segment of arc that I'm on, I'll take either an extra 10 degrees (if the wind is "from the FOR") or only 10 degrees (if the wind is "to the VOR"). Almost as easy as GPSS

Fly safe!

David

 

[flyingcheesehead]

Time to contact NACO...

Well, the letter has been sent... I'll post a response if I get one. IIRC, last time I contacted NACO about an approach plate, I had an answer in a hurry. Those folks definitely move MUCH faster than the speed of government.

Hello,

In reviewing the LOC/DME RWY 36 approach into FLD, version Orig 08157 on page 297 of the current (31 Jul-25 Sep 2008) EC-3 approach book, I've noticed what appear to be some errors:

The only marked IAF's are DOYAG and ERAGE intersections at either end of the DME arc and the Badger (BAE) VOR. The first error, in my reading of the chart, is that CADVU is not marked as an IAF. There is a feeder route from the OSH VOR that says "2800 to Cadvu" but were CADVU not an IAF, it's unclear what IAF should be used. It appears that the intent is for CADVU to be an IAF and for the procedure turn to be required when using the transition from the OSH VOR.

Additionally, there is a feeder route marked from the BAE VOR. While BAE is marked as an IAF and the procedure would appear to proceed along the 341 radial off BAE to GODEC IF, that route is marked as a feeder route and not the procedure track. To my understanding, either GODEC should be an IAF, or the route from BAE to GODEC should be marked with a bold arrow to indicate that it is part of the procedure track and not a transition.

Thank you for your attention to this matter. If I am misunderstanding the chart at all, I would greatly appreciate an explanation.

Thanks,

 

[flyingcheesehead]

Ok now I looked at the replacemennt for the SDF the new LOC/DME 36 at Fond du lac.

Huh... No more SDF, eh? I flew that approach a couple of times. Heck, that was the first DME arc I ever flew. Looking on Airnav, I only found about 5 SDF approaches left in the whole US.

Interestingly enough, the VOR/DME 36 approach also has arcs 26 DME from OSH, but they start further out. However, when flying to FLD for real, if for any reason I wasn't going to land on 36, or if the weather was above the mins for the VOR/DME 36, I'd rather fly the VOR/DME 36 arcs than the LOC/DME 36 arcs: In the event I was circling (circling mins are the same) or the clouds were high enough (so I wouldn't NEED the LOC/DME to get in), well, I wouldn't have to switch the DME from OSH to I-FLD when making the turn inbound. I've never seen a flip-flop DME.

 

[poadeleted20]

Oddly enough, looking at the various transition routes and such, by the markings on the plate it appears that CADVU and GODEC should both be marked as IAF's, and BAE should NOT be marked as an IAF. (Ever seen a transition route from an IAF before?)

CADVU, yes; GODEC, no. GODEC is listed an IF, not an IAF. Other than with GPS, there's no way to navigate oneself to GODEC other than from BAE which is an IAF -- all you can do is get vectors onto the LOC, and then you don't need an IAF. With a GPS, they can clear you direct to the IF as long as that course is within 90 degrees of the IF-FAF course and you're exempt from the requirement to cross an IAF. As for Badger VOR, I agree -- something's mismarked. If it's an IAF, it should be a heavy black line to the IF; if not, GODEC would have to be an IAF.

In any event, I agree that the charting wonks need to re-examine this chart.

 

[flyingcheesehead]

CADVU, yes; GODEC, no. GODEC is listed an IF, not an IAF. Other than with GPS, there's no way to navigate oneself to GODEC other than from BAE which is an IAF -- all you can do is get vectors onto the LOC, and then you don't need an IAF. With a GPS, they can clear you direct to the IF as long as that course is within 90 degrees of the IF-FAF course and you're exempt from the requirement to cross an IAF. As for Badger VOR, I agree -- something's mismarked. If it's an IAF, it should be a heavy black line to the IF; if not, GODEC would have to be an IAF.

Agreed... I think there are two possibilities though: One is that BAE is correctly marked as the IAF and GODEC as the IF in which case the route from BAE to GODEC should be marked as a procedure route (heavy black line) and not a feeder route (lighter black line).

The other possible case is that the arrow was correctly marked as a feeder route, and in that case BAE should not be an IAF but GODEC should, and you'd still be able to navigate to GODEC from BAE. It's more of a semantics thing than a procedural thing, but there's an error one way or the other.

I think it's pretty clear, though, that CADVU should be an IAF.

 

[flyingcheesehead]

Well, the letter has been sent... I'll post a response if I get one. IIRC, last time I contacted NACO about an approach plate, I had an answer in a hurry. Those folks definitely move MUCH faster than the speed of government.

Well, I got a response, and so far at least half of it will be fixed:

Mr. Shook,
Thank You for contacting us here at the NACG. I agree that the route from BAE to GODEC should be marked as a procedure track vice a transition route. On the question of whether CADVU should be an IAF or not, I would like to refer you to the National Flight Procedures Office since the procedure was developed on their end. The procedure states that CADVU is not an IAF. The contact for you is Mr. Larry Strout at (000) 000-0000 or email to Blah.D.Blah@faa.gov The route between BAE and GODEC will be revised to reflect a procedure track for the 23 OCT 08 Change Notice. Again, Thanks for bringing this to our attention.

Kevin M. Flowers
FAA/National Aeronautical Charting Group (NACG)

So, I wrote another note to Mr. Strout. Hopefully the other issue will get fixed too.

Agreed... I think there are two possibilities though: One is that BAE is correctly marked as the IAF and GODEC as the IF in which case the route from BAE to GODEC should be marked as a procedure route (heavy black line) and not a feeder route (lighter black line).

The other possible case is that the arrow was correctly marked as a feeder route, and in that case BAE should not be an IAF but GODEC should, and you'd still be able to navigate to GODEC from BAE. It's more of a semantics thing than a procedural thing, but there's an error one way or the other.

I think it's pretty clear, though, that CADVU should be an IAF.

 

[CJones]

Well, I got a response, and so far at least half of it will be fixed:



So, I wrote another note to Mr. Strout. Hopefully the other issue will get fixed too.

Wow, Kent. You go without a job for a while and look how productive you become!! You're an inspiration to us all. I think we should ALL go jobless in honor of Kent's accomplishments.

 

[vontresc]

Who knows maybe Kent could get a job at the FAA....

 

[CJones]

Sorry, Pete, but I think....

...look how productive you become!! ...

and

...job at the FAA....

are mutually exclusive statements.

By the way, if the FAA is reading this, my name is Tony Condon and I am a CFI, my cert number is....

 

[flyingcheesehead]

Who knows maybe Kent could get a job at the FAA....

Hey, now you're on to something.

No official answer yet, but we talked about it for a bit in chat tonight...

Fast n' Furious: Okay. Simply put. If you wanted to make that route a feeder you would have to have two DME operating at the same time given the divergence angle. As the nice folks at 420 would never allow that to happen that route can't be a feeder. The distance is purely advisory.
Fast n' Furious: IOW, we don't measure the DME on that segment and without positive guidance it's just good to know stuff.
Fast n' Furious: Don't ya hate stuff like that?
flyingcheesehead: John... Why two DME? Get on the 168 radial off OSH, go 13 miles or so, flip the DME to the localizer to identify CADVU...
flyingcheesehead: Is the reason for that just because if you had the DME on the localizer the whole time that you might mistake CADVU for a point 5 north of the airport?
flyingcheesehead: But in that case, I don't think you'd be on the localizer (or the backcourse) yet...
flyingcheesehead: I'm confused.
flyingcheesehead: I mean, why is it even marked if it's not a feeder? And why is there a PT marked when there's no other routes that use one?
Fast n' Furious: Exactly. Having to work between two DMEs to exactly fix you position in space is confusing. Like the man said, I don't code 'em...I just approve em.
RMCN172RG: what approach are we discussing?
flyingcheesehead: This one: http://204.108.4.16/d-tpp/0809/0*5231LD36.PDF
flyingcheesehead: Trying to figure out the purpose of what looks like a feeder off OSH, and why CADVU should (or shouldn't) be marked as an IAF.
jmaynard: Okkay, then...if CADVU isn't an IAF and neither is OSH, how do you get there? (Aside from inbound, of course.)
Fast n' Furious: Apart from that...as OSH isn't an IAF that radial can't be a feeder.
flyingcheesehead: There's three IAF's Jay - BAE and the two ends of the DME arc. Those should be marked on the enroute chart.
flyingcheesehead: John, if it were a feeder as opposed to a procedure route, wouldn't CADVU be the IAF?
Fast n' Furious: If it met criteria, probably.
flyingcheesehead: So John, if there were a higher angle between the OSH VOR and the FAC, would it be OK then?
Fast n' Furious: Right now, it's just another happy radial taking you on a journey towards a LOC while has DME that you should be monitoring.
flyingcheesehead: Hmmm... Under what circumstances could you/would you fly that route?

 

[flyingcheesehead]

Well, I got a response, and so far at least half of it will be fixed:

Mr. Shook,
Thank You for contacting us here at the NACG. I agree that the route from BAE to GODEC should be marked as a procedure track vice a transition route. On the question of whether CADVU should be an IAF or not, I would like to refer you to the National Flight Procedures Office since the procedure was developed on their end. The procedure states that CADVU is not an IAF. The contact for you is Mr. Larry Strout at (000) 000-0000 or email to Blah.D.Blah@faa.gov The route between BAE and GODEC will be revised to reflect a procedure track for the 23 OCT 08 Change Notice. Again, Thanks for bringing this to our attention.

Kevin M. Flowers
FAA/National Aeronautical Charting Group (NACG)

So, I wrote another note to Mr. Strout. Hopefully the other issue will get fixed too.

Agreed... I think there are two possibilities though: One is that BAE is correctly marked as the IAF and GODEC as the IF in which case the route from BAE to GODEC should be marked as a procedure route (heavy black line) and not a feeder route (lighter black line).

The other possible case is that the arrow was correctly marked as a feeder route, and in that case BAE should not be an IAF but GODEC should, and you'd still be able to navigate to GODEC from BAE. It's more of a semantics thing than a procedural thing, but there's an error one way or the other.

I think it's pretty clear, though, that CADVU should be an IAF.

Well, I never did hear back from the flight procedures office, but I was looking at this approach today, and CADVU is now marked as an IAF. Score one (or two, really!) for PoA!

http://204.108.4.16/d-tpp/0901/05231LD36.PDF

 

[jesse]

DME Arcs are simple provided you don't complicate them. Some people try to track their progress way to often which greatly increases their workload leading to higher stress and mistakes.

Are you doing the "Twist ten, Turn ten" on the VOR needle and DME readout or GPS distance?

That is a good example, in my opinion, of complicating it. I don't sit there and do it ten degrees at a time. I know I'm in the right direction, I know I'm at the right distance. No reason to mess with instruments that much.


Crap. Old thread...oh well

 

[KennyFlys]

DME Arcs are simple provided you don't complicate them. Some people try to track their progress way to often which greatly increases their workload leading to higher stress and mistakes.


That is a good example, in my opinion, of complicating it. I don't sit there and do it ten degrees at a time. I know I'm in the right direction, I know I'm at the right distance. No reason to mess with instruments that much.

Complicating it, how? Is there another procedure to use?

 

[gismo]

Complicating it, how? Is there another procedure to use?

Given that I haven't flown a DME arc without a magenta line to follow (and a roll steering autopilot to track it for me) you might want to take this with a grain or two of sodium chloride but I remember finding it very easy to do without constantly adjusting the CDI. I used a centered CDI to establish an initial heading to take when the arc was intercepted (DME distance correct) and then just turn towards the ground station 5-10 degrees every time the distance got about a tenth or two higher than the specified distance. I would normally set the OBS on the #2 nav to indicate a lead in radial if available and the #1 set to show the final course guidance.

Unlike the turn&twist this works even if the DME ground station isn't a VOR although I don't know if those are ever used for a published arc. In any case it leaves your hands free to deal with other stuff (like belatedly reviewing the approach plate or changing com freqs).

 

[KennyFlys]

Given that I haven't flown a DME arc without a magenta line to follow (and a roll steering autopilot to track it for me) you might want to take this with a grain or two of sodium chloride but I remember finding it very easy to do without constantly adjusting the CDI. I used a centered CDI to establish an initial heading to take when the arc was intercepted (DME distance correct) and then just turn towards the ground station 5-10 degrees every time the distance got about a tenth or two higher than the specified distance. I would normally set the OBS on the #2 nav to indicate a lead in radial if available and the #1 set to show the final course guidance.

Unlike the turn&twist this works even if the DME ground station isn't a VOR although I don't know if those are ever used for a published arc. In any case it leaves your hands free to deal with other stuff (like belatedly reviewing the approach plate or changing com freqs).

Lance, I do understand the GPS following and that's what most will do. I'm of the old school on remaining proficient on needles. Anyone can follow a magenta line on a mape. But someday, that magenta line may not be there and it's back to the basics. Many such pilots are destined to become a statistic.

As I've been saying... "Magenta lines kill pilots."

 

[gismo]

Lance, I do understand the GPS following and that's what most will do. I'm of the old school on remaining proficient on needles. Anyone can follow a magenta line on a mape. But someday, that magenta line may not be there and it's back to the basics. Many such pilots are destined to become a statistic.

As I've been saying... "Magenta lines kill pilots."

Well, I've survived many a magenta line so far...

I do agree that one should be able to survive when one or two failures change your navigation capabilities and I'm pretty sure I can still follow a needle when necessary.

But what do you think of the arc tracking method I mentioned? It doesn't rely on any colored lines.

 

[Trapper John]

Lance, I do understand the GPS following and that's what most will do. I'm of the old school on remaining proficient on needles. Anyone can follow a magenta line on a mape. But someday, that magenta line may not be there and it's back to the basics. Many such pilots are destined to become a statistic.

As I've been saying... "Magenta lines kill pilots."

That's just a tad dramatic, isn't it? And, really, it would be the absence of the expected magenta line that would be the problem.

But let's think about this a little more. If your handy G1000 throws craps in IMC, and you want to land ASAP are you going to:

a) Get vectors from ATC to execute a ILS or at least localizer approach,
or

b) Fly your own DME arc.

I vote "a".


Trapper John

 

[gismo]

That's just a tad dramatic, isn't it? And, really, it would be the absence of the expected magenta line that would be the problem.

But let's think about this a little more. If your handy G1000 throws craps in IMC, and you want to land ASAP are you going to:

a) Get vectors from ATC to execute a ILS or at least localizer approach,
or

b) Fly your own DME arc.

I vote "a".


Trapper John

If I were unsure of my ability to fly whatever approach was needed at my planned destination and/or lacked the ability to get there sans GPS I'd go for 'a' as well if it were available. But I can certainly see the potential that no such options exist. Most of the places I go don't have the option of vectors to final on any approach and in many cases the nearest ILS is a fair distance away. Couple the GPS outage with minimal radar low altitude radar coverage and insufficient fuel to make a diversion to somewhere that vectors to an ILS exist and you have a situation where "flying the needles" will be the best choice. That said, I don't agree with Ken that there are many pilots flying IFR who are gonna become a statistic just because their magenta lines dissapear.

 

[Everskyward]

But what do you think of the arc tracking method I mentioned? It doesn't rely on any colored lines.

Lance, I've used your arc tracking method with and without a magenta line and it works fine for me. However, I should add that I always had an HSI and an RMI. I think I have forgotten how to use a regular CDI.

As far as the magenta line goes, one thing I might point out is that if you program your GPS wrong, not only will the magenta line be wrong but the needles will be wrong as well, and with many procedures these days there are no ground-based backups. I think the key is to be able to use everything available in the airplane correctly.