DME arc SNAFU question:

fiveoboy01

fiveoboy01

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Dirty B
KPSC VOR/DME 21R:

50173184-99d7-4f64-b800-24497a652210.png


Let's say you're cleared for the approach and you proceed to EXODE. You fly the arc and because of whatever reason(distracted, OBS set wrong, whatever), instead of turning onto the final approach course, you overshoot and find yourself on the opposing arc, let's say the 060 radial. Now I realize this is an enormous screw up, but let's say someone did it.

What do you do? Way too far to turn back onto the final approach course.

Also I realize that approach control would say something in this particular instance, but let's assume that perhaps it's a non-towered field and you've been switched to CTAF prior to your mistake.
 
Disclaimer: I don't know the *real* answer but, if I found myself in that position (prior to reading what I expect to be a number of enlightening posts giving better answers), what I would do is:

1) Climb to the MSA of 2900', if I'm not already there.

2) Contact approach. I was talking to them before switching to CTAF, so I'm going back to them since I'm now "enroute" again vs. on an actual approach (I'm on the plate, but going the wrong direction). Admit the mistake and ask them for further vectors.

3) Once I'm on the ground, figure out how the hell I allowed that to happen and hopefully learn from the mistake.

But, in case the question was meant more as "How would you get back on the approach IN AN EMERGENCY where you couldn't make contact with anyone else?" I guess the best option would be:

1) Climb to the MSA of 2900', if I'm not already there.

2) Squawk 7700 (If we stipulated this is an emergency, I'd go 7700 instead of 7600. Even though either would seem appropriate, 7700 trumps 7600 to me.)

3) Fly the hold at CITYS in order to reverse course and then fly the left turning arc back to the final approach course.

4) Once I'm on the ground, figure out how the hell I allowed that to happen and hopefully learn from the mistake.

Obviously, if I'm in VMC I'd squawk 7600 and land as soon as practicable... and then call FSS to let them know I'm down and close my flight plan. Followed by the "Figure out how the hell I allowed that to happen" step from above.

I await more enlightened answers...
 
Actually, I'd climb to 3200 and navigate towards CITYS while trying to raise ATC. This is in line with the missed approach procedure
 
I never thought about lost comms.

Contacting approach and admitting your screw up seems to be the most obvious thing to do, but your thought about radios out is a good one.

I know it's a really weird question. I was just watching some videos to refresh myself on arcs and the narrator mentioned overshooting the final approach course and this question popped into my head. Assuming you overshoot the localizer a little you can turn back onto it, this is way past that point.

Maybe it's so unlikely to happen that it's a dumb scenario, but I'm bored waiting to start work:)
 
What ever the correct procedure turns out to be, kudos for asking a good question!
 
flyingron said:
Actually, I'd climb to 3200 and navigate towards CITYS while trying to raise ATC. This is in line with the missed approach procedure
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Obviously, 3200' is better than 2900' but I figured the MSA for the area we'd be in was 2900' so I'd go AT LEAST that high. But definitely not a bad idea to climb to the missed approach altitude. Upon further review, I'd like to change my answer to include the climb to 3200'.
 
You don't even really need the "kept going to the opposite arc" for the scenario.

Just say you find yourself having made a mistake and you realize you're no longer on the arc or any other portion of the published approach -- which could happen on any approach.

It's a miss and you have to think about where you're headed next. Preferably not into a rock.

The arc just adds another twist to it in that you may be pointed a very bad direction. Terrain, towers, whatever.

Time to climb to a safe altitude and execute plan B. Or C. Or D. Or E.
 
denverpilot said:
You don't even really need the "kept going to the opposite arc" for the scenario.

Just say you find yourself having made a mistake and you realize you're no longer on the arc or any other portion of the published approach -- which could happen on any approach.

It's a miss and you have to think about where you're headed next. Preferably not into a rock.

The arc just adds another twist to it in that you may be pointed a very bad direction. Terrain, towers, whatever.

Time to climb to a safe altitude and execute plan B. Or C. Or D. Or E.
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The nice thing about the question including the arc, though, is that you can reasonably be assured obstacle clearance while ON the arc segment at or above the published altitude (even though you're flying it "backwards"). But you're right... not being on the arc could bring additional concerns (if MSA is above the published altitude for the arc).
 
Let's say it's Ed flying and he's got one VOR and a DME and nothing else:p
 
:D

My serious answer is missed approach procedure, call center/approach and do it all over again, OR call approach/center, confess, and get vectors to one of the IAF's
 
EdFred said:
:D

My serious answer is missed approach procedure, and do it all over again, OR call approach/center, confess, and get vectors to one of the IAF's
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What would that look like from the 060R from PSC? You wouldn't go direct to the VOR and then go missed, would you? When you have a perfectly good arc to fly to the missed approach hold? That's why I'd fly the arc and then enter the hold, with the expectation that approach would clear me for another try in the opposite direction. And, if lost comms, I'd squawk it, reverse course in that hold and then fly the arc to the final approach course (and be EXTRA careful not to miss it again) and then inbound.
 
mjburian said:
What would that look like from the 060R from PSC? You wouldn't go direct to the VOR and then go missed, would you? When you have a perfectly good arc to fly to the missed approach hold? That's why I'd fly the arc and then enter the hold, with the expectation that approach would clear me for another try in the opposite direction. And, if lost comms, I'd squawk it, reverse course in that hold and then fly the arc to the final approach course (and be EXTRA careful not to miss it again) and then inbound.
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Well, the missed isn't fly to the VOR and then intercept the 092 radial. It's climb and turn to intercept the 092 radial, by flying southeastward. So I'd intercept it by flying southeastward, and I'd conveniently intercept the 092 radial at the fix, and pretty close to the arc. Probably just go direct to the fix though.

Also, you shouldn't have to climb because you should have been at 3200 for that segment anyway.
 
mjburian said:
The nice thing about the question including the arc, though, is that you can reasonably be assured obstacle clearance while ON the arc segment at or above the published altitude (even though you're flying it "backwards"). But you're right... not being on the arc could bring additional concerns (if MSA is above the published altitude for the arc).
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Good point. Have to take all info into account.

@jesse essentially did this to me at night by failing stuff just when I was getting cocky. Ha.

*In my head* I didn't know if I was still on the arc or not. He coached me through figuring that out and continuing the arc without the DG (he knew I had a penchant for not cross referencing the mag compass because I thought looking up there was "cheating" but you have to!) and then we chatted the rest of the way around the arc on "what would you really do?" if you found yourself messing around on an arc not quite sure of the aircraft location due to a failure, a brain fart, or whatever.

The lesson was a good one. Climb and figure out how to "go missed" in a safe direction and live to fight another day, in the real world.

For added fun, he pointed out a lighted tower off of our right wing (it was a left arc) that was *above* us as we went by. It was a "safe" FAA approved distance away from the arc itself, but a few miles and you'd find it, heading the wrong direction...

Which makes your point about the arc and its published altitude being obstacle free... If you know you're on it...

I was ****ed that I let him "gotcha" me that easily. But that was his job... Ha. Got my attention for sure.

To be honest, it probably also highlighted something else -- I doubt if given the option, that willfully choosing the DME arc in pitch black nowhere Nebraska single pilot and at 1AM would have been a smart ADM move if it were a real-world flight and not training, if other approach options were available. I'm usually not 100% on my game at 1AM and I know it. :)

(Which in the end probably made a lot of that middle of the night IFR training harder and more useful to see how I react to being fatigued -- something not many pilots actively seek out during training. Can't cheat as easily with a peek in nowhereville at night, can't completely shake the sleepies and yawns, might not notice a real world gyro failure as easily as some guy reaching over to cover the thing up... And you have to do it right or splat yourself over a corn field... It'll make you think hard about whether you'd launch at sunset into IMC, a statistically higher way to die... I highly recommend folks do a late night IFR training flight sometime with a night owl instructor, assuming the risk level of flying a single at night is "okay" with you both. There's always that problem, too. It teaches you some things about yourself you won't notice during daytime when you're 100% present and on top of things. Things you should learn in a controlled environment and not behind the power curve someday later when you decided "oh, it's only a short flight and the weather looks like it'll hold...")
 
EdFred said:
Well, the missed isn't fly to the VOR and then intercept the 092 radial. It's climb and turn to intercept the 092 radial, by flying southeastward. So I'd intercept it by flying southeastward, and I'd conveniently intercept the 092 radial at the fix, and pretty close to the arc. Probably just go direct to the fix though.
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If you fly southeast from the 060R, I think you're going to miss the fix to the east. But I guess direct the fix would make sense. I'm /A, though, so can't easily go direct the fix from that point without using the arc.
 
Not EXACTLY southeast. But southeast from DMAGY (I think that's what the fix is at the two DME arcs) When I say SE, I mean between 090 and 180.
 
denverpilot said:
Good point. Have to take all info into account.

@jesse essentially did this to me at night by failing stuff just when I was getting cocky. Ha.
[snip]
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That sounds like a really good idea, actually. A "what if" session while purposely fatigued could give you some insight into how you'd react in that state... and maybe keep you from launching if that was the case (or even likely/possible). I fly at night and so does my instructor. Now, to figure out a way to get him to take a disco nap midday so at least one of us is on the ball in the middle of the night. Also, I'd be much more likely to do this in VMC under the foggles than in IMC, but I'm still a pretty low (actual) time instrument pilot.
 
EdFred said:
Not EXACTLY southeast. But southeast from DMAGY (I think that's what the fix is at the two DME arcs) When I say SE, I mean between 090 and 180.
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Got it. Was just trying to make sure I understood what you were saying, because this post really got me thinking.
 
Very good question, not easy to answer (for me, an instrument newbie). I do not recall (off the top of my head) any regulation governing this scenario specifically but I believe that Ron is technically right, it might be a missed approach scenario.

Food for thought: you are protected 2 miles on each side of the DME arc so making a tear-drop course reversal to turn back toward the IF would not be unsafe (provided your speed and wind allows you to stay inside the 2-mile buffer), however probably not per procedural regulations.

What do our resident CFIIs say?
 
It seems everyone missed that both arcs are to be flown at or above 3200 over their entire length.

No climb necessary. You're above the MSA, and you're already at the missed approach altitude.

We're pretending this is nontowered, so no more than one airplane can be on the approach at a time. So, it's safe, and probably best, to continue level along the arc to the missed approach hold. It's not much worse to fly a 270 (still level at 3200) or teardrop back to the inbound course. You are above the MSA.

Note that it's not realistic to suppose you've been handed off to CTAF on the arc. That happens near the FAF.
 
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mjburian said:
Got it. Was just trying to make sure I understood what you were saying, because this post really got me thinking.
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Yeah, more like SE from the FAC. And if you are /A, your best bet is going to be the arc. Because really, what's your other option? You aren't going to parallel the FAC while /A. I mean you could, but you'd be making up your own route.
 
EdFred said:
Yeah, more like SE from the FAC. And if you are /A, your best bet is going to be the arc. Because really, what's your other option? You aren't going to parallel the FAC while /A. I mean you could, but you'd be making up your own route.
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Right, and I think that was part of my confusion with your initial answer. I forget that some people get to fly equipment from sometime in the last few decades. ;-)

In an emergency, if I find myself off of the arc and off of the FAC as well... I guess my best bet is climb and check my location in Foreflight. But, that'd mean I screwed up a few different ways. Which, hopefully, wouldn't happen. *knocks on wood
 
MAKG1 said:
It seems everyone missed that both arcs are to be flown at or above 3200 over their entire length.

No climb necessary. You're above the MSA, and you're already at the missed approach altitude.

This is nontowered, so no more than one airplane can be on the approach at a time. So, it's safe, and probably best, to continue level along the arc to the missed approach hold. It's not much worse to fly a 270 (still level at 3200) or teardrop back to the inbound course. You are above the MSA.
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Yep, I missed it at first and changed my answer to "climb to 3200 feet" but also said "if I'm not already there". I definitely *should* already be there, but I also shouldn't have missed the final approach turn, so...
 
mjburian said:
Right, and I think that was part of my confusion with your initial answer. I forget that some people get to fly equipment from sometime in the last few decades. ;-)

In an emergency, if I find myself off of the arc and off of the FAC as well... I guess my best bet is climb and check my location in Foreflight. But, that'd mean I screwed up a few different ways. Which, hopefully, wouldn't happen. *knocks on wood
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If I found myself off the arc and off the FAC, and I was /A, I would spin the OBS to find out which radial I was on. I now have my distance from and my radial. From there I ballpark the most expeditious way to the 092 radial while remaining inside the 14 DME arc.
 
mjburian said:
That sounds like a really good idea, actually. A "what if" session while purposely fatigued could give you some insight into how you'd react in that state... and maybe keep you from launching if that was the case (or even likely/possible). I fly at night and so does my instructor. Now, to figure out a way to get him to take a disco nap midday so at least one of us is on the ball in the middle of the night. Also, I'd be much more likely to do this in VMC under the foggles than in IMC, but I'm still a pretty low (actual) time instrument pilot.
Click to expand...

Well ... Not saying he wouldn't need to be on his game, but if it's an approach he knows and has flown with students in daylight, a little fatigue over there in the non-hot-seat and a little help from an iPad at making sure you're both not somewhere you don't want to be, and I doubt the disco nap is even truly needed. ;)

Another plus of doing it late at night, probably no vectors for traffic or conflicts. Ha. Some of the places we went didn't look like they saw many airplanes even on a busy day, we were definitely by ourselves for multiple approaches. The controllers pretty much sounded like we were waking THEM up half the time when we'd pop back up on a missed. Ha. The tone of voice was usually "yeah, yeah, do whatever you want, nobody is out there anyway..." Haha.
 
flyingron said:
Actually, I'd climb to 3200 and navigate towards CITYS while trying to raise ATC. This is in line with the missed approach procedure
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This. It keeps it simple. Do the turn in holding and do the approach from there. Traffic will be no factor, the missed approach will be protected and ATC should assume you will do the approach again or procede to your alternate. They should be protecting for both.
 
I'd personally climb to 3500 going towards CITYS in case I drifted past the 280 radial turning around if I were in IMC. A little altitude never hurt no-one. Then go back down to 3200 once past CITYS coming back in.
 
That hold is going to have plenty of protected area around it.
 
The Arc is protected out to the next county. +/- 4 NM either side of center is the primary area, another 2 NM beyond that is the secondary area. ROC is 1000 feet.

If you are already screwed up, continue on at 3200 to the missed approach hold and hold. Call ATC, request a do over.
 
BigBadLou said:
Food for thought: you are protected 2 miles on each side of the DME arc so making a tear-drop course reversal to turn back toward the IF would not be unsafe (provided your speed and wind allows you to stay inside the 2-mile buffer), however probably not per procedural regulations.
Click to expand...

A DME arc is protected 6 miles each side of centerline; 4 mile primary each side of centerline, with a 2 mile secondary each side of those primaries.
 
Textbook answer may be continue on arc to CITYS and hold while advising ATC.

The real-world practical answer at that point is do a left 180, back to the arc (or a 210+ to put you on the intercept for final), intercept the final approach course and get on the ground. ATC has protected ALL that airspace for you. You're well above the MSA at that point and will remain in the protected space of the arc in the turn. The best scenario for all involved is to get you safely on the ground as soon as possible.
 
LDJones said:
Textbook answer may be continue on arc to CITYS and hold while advising ATC.

The real-world practical answer at that point is do a left 180, back to the arc (or a 210+ to put you on the intercept for final), intercept the final approach course and get on the ground. ATC has protected ALL that airspace for you. You're well above the MSA at that point and will remain in the protected space of the arc in the turn. The best scenario for all involved is to get you safely on the ground as soon as possible.
Click to expand...

IMO the right answer, as others have posted, is to immediately execute the missed approach procedure. Anytime any approach gets buggered that's what you're supposed to do, not improvise some BS on the fly.
 
tsts4 said:
IMO the right answer, as others have posted, is to immediately execute the missed approach procedure. Anytime any approach gets buggered that's what you're supposed to do, not improvise some BS on the fly.
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I would do the miss procedure also. Reminds me of flying into Monterrey Mexico on the arc there for the ILS. Most of the time you can't see the mountains that form a semi circle around the city because of the smog (from American factories there) but when you can see them, wow, makes you glad you're on the arc. Even though you're protected on either side of the arc, a 180 degree turn around to intercept the arc again is foolish IMO.
 
LDJones said:
Textbook answer may be continue on arc to CITYS and hold while advising ATC.

The real-world practical answer at that point is do a left 180, back to the arc (or a 210+ to put you on the intercept for final), intercept the final approach course and get on the ground. ATC has protected ALL that airspace for you. You're well above the MSA at that point and will remain in the protected space of the arc in the turn. The best scenario for all involved is to get you safely on the ground as soon as possible.
Click to expand...

I suspect the real-world practical answer is that approach control would be all over a pilot blowing the turn onto the localizer.
 
fiveoboy01 said:
KPSC VOR/DME 21R:

50173184-99d7-4f64-b800-24497a652210.png


Let's say you're cleared for the approach and you proceed to EXODE. You fly the arc and because of whatever reason(distracted, OBS set wrong, whatever), instead of turning onto the final approach course, you overshoot and find yourself on the opposing arc, let's say the 060 radial. Now I realize this is an enormous screw up, but let's say someone did it.

What do you do? Way too far to turn back onto the final approach course.

Also I realize that approach control would say something in this particular instance, but let's assume that perhaps it's a non-towered field and you've been switched to CTAF prior to your mistake.
Click to expand...
Confess, communicate, and head to citys via the arc
 
LDJones said:
Textbook answer may be continue on arc to CITYS and hold while advising ATC.

The real-world practical answer at that point is do a left 180, back to the arc (or a 210+ to put you on the intercept for final), intercept the final approach course and get on the ground. ATC has protected ALL that airspace for you. You're well above the MSA at that point and will remain in the protected space of the arc in the turn. The best scenario for all involved is to get you safely on the ground as soon as possible.
Click to expand...

I'd probably do this unless whatever caused me to miss the turn in the first place had me feeling getting behind the airplane. If things were feeling weird I'd continue to CITYS, enter the hold and start over.
 
luvflyin said:
I'd probably do this unless whatever caused me to miss the turn in the first place had me feeling getting behind the airplane. If things were feeling weird I'd continue to CITYS, enter the hold and start over.
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You'd need a new clearance to do that.
 
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