When to descend?

[TonyC]

You guys have too many balls in the air at once.

That just makes it more interesting.

You're established, in your scenario, when you're on the arc. That means when you're at 12 miles. The +/- stuff is a PTS standard that is not applicable to anything but a Practical Test. You're supposed to stay at the correct distance all the time.

So, I begin the left turn at 13.1, when the DME reads 12.0 I begin my descent. I roll out with too much drift correction, so I eek out to 12.1. Do I climb back up?

I'm not asking for a tolerance. I realize the goal is to maintain 12.0 exactly. But, if 12.0 exactly were required to descend, none of us humans could fly the approach.

Established with respect to any type of course guidance means when you are on the centerline of the course in question.

So, when you're cleared to fly a LOC or VOR or NDB appraoch, are you saying you don't begin descent on final until the needle is exactly centered? Something tells me you either consider yourself established using a more lenient criteria, or you're a heckuva lot better than us, or you do a lot of missed approaches.


Now, whatever criteria it is that you use to maintain that centerline, or determine "established", whether it be measured in degrees or needle widths, or dots, or whatever, they don't apply to an arc. Arcs don't have a "centerline" per se. The only measure I can imagine that would apply to an arc would be measured in Nautical Miles DME. The DME might be an absolute number (say, 1 NM?) or it might be a percentage of the arc (10% of 12 would be 1.2?) or it might be based on aircraft category, or... well, I don't know. I just can't find anything to say, one way or another, what constitutes "established" on an arc for the purposes of beginning a descent.

I've seen an FAA interpretation from the guy in Washington who knows all about what the regs mean (someone here must remember his name - I can't). If you can find him you can probably locate the same source for this info that I did.

Boy, I'd like to meet the guy that knows all about what the regs mean. Does he go by Avbug, by chance?








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[A Squared]

THe Arc has the same protection as an airway, which is to say, 1000' above any obstacle 4 nm from centerline, and 500' tapering to zero from 4nm to 8nm. If a fed or a check airman was looking over my shoulder, i'd probably wait until I had completed the turn onto the arc, merely because it's a grey area and who knows what opinion (right or wrong) that guy holds. ie: the most conservative approach is the path of least resistance when subject to official oversight. Left to my own devices, I have no qualms about starting a descent as I start my turn onto the arc (about 1.5-1.7 NM before the arc) after all I'm 6.5 miles past anything I could possibly hit at arc altitude (assuming correct altimeter setting) and it's another 9.5 nm until anything else I could hit.

 

[PropsR4Boats]

Tony C,

Ask me some specific questions; I will answer them with references. After I do that I will let you take me to Ruth’s and you better not stick me with the bill.

Vectors4fun what facility do you work.

Props

 

[A Squared]

..........In addition once an approach clearance is given altitude is the pilot’s discretion to the lowest permissible altitude, unless there is a specific crossing instruction or other ATC instruction..........

PropsR4Boats,

Can you direct me to exactly where in the AIM it says this?

 

[Yellow Snow]

Vectored and TIS are 100% correct. Established in the hold is when you are centered on the inbound leg. You guys are quoting the AIM like it is regulation and it isn't. The AIM is informational. It is helpful and will make life easier but it isn't regulation. The pattern entries, for example, are nice suggestions but you can enter a pattern any way you like as long as you stay in the protected airspace. If you are cleared for an approach you may, when established on a published segment, descend to the altitude allowed by that procedure.

 

[PA31Ho]

you are 'established in a hold' once established on the inbound leg... great!

Another question, in relation to the barb. Say you are flying straight to ASHLY LOM (IAF), you have to make a right turn initally for the PT, however once you are flying the 018 heading, you have to stay on the left side of that barb? Or can you make a right turn if you'd like?

I just want to clarify some of these questions because some people have different answers than the other when I ask around at the airport, just wanting to get other opinions as well.

Thanks

 

[MTpilot]

Follow the Barb

I didn't look at the approach but the barb denotes the direction of the procedure turn, that is the way you have to go.

 

[TonyC]

Tony C,

Ask me some specific questions; I will answer them with references. After I do that I will let you take me to Ruth’s and you better not stick me with the bill.

Props,

Ya gotta pay attention. I've already asked the question - - read the thread.


What constitutes "established" with regards to an approach segment defined by a DME arc?



I'm not looking for PTS standards. I'm not looking for "maintain certerline." I'm not looking for TERPs obstacle clearance design. I've been through all that, and though it is very informative, it doesn't answer the question, "what is established?".






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[PropsR4Boats]

I see, there was a lot of talk about other stuff. Some people where talking about holds, etc. Hang on and I'll find it for you.

Of course if you just stayed right on course you wouldn't have to worry, just kidding.

Seriously I see what I can find you. Oh by the way there is a Ruth Chris within walking distance of the crew hotel I’m in.

 

[TIS]

You guys are quoting the AIM like it is regulation and it isn't. The AIM is informational. It is helpful and will make life easier but it isn't regulation.

Actually, this is a popular idea but it isn't true - when you have to answer the tough questions from across the big conference table. The FAA treats the AIM as gospel if you become involved in something and they can show that you didn't follow their suggestions. In fact, they use it to help support the 91.13 careless or reckless charge they append to any filing against an airman.

In other words, "You didn't do things the way we said to and now look where you've ended up!"

The pattern entries, for example, are nice suggestions but you can enter a pattern any way you like as long as you stay in the protected airspace.

True to a point. If you're on a practical test of any kind this is NOT true. the PTS specifies that you must use the appropriate entry from the AIM.

If you are cleared for an approach you may, when established on a published segment, descend to the altitude allowed by that procedure.

Correct!

TIS

 

[TIS]

Oh by the way there is a Ruth Chris within walking distance of the crew hotel I’m in.

You in Weehawken?

 

[TIS]

That just makes it more interesting.

So, I begin the left turn at 13.1, when the DME reads 12.0 I begin my descent. I roll out with too much drift correction, so I eek out to 12.1. Do I climb back up?

I'm not asking for a tolerance. I realize the goal is to maintain 12.0 exactly. But, if 12.0 exactly were required to descend, none of us humans could fly the approach.


So, when you're cleared to fly a LOC or VOR or NDB appraoch, are you saying you don't begin descent on final until the needle is exactly centered? Something tells me you either consider yourself established using a more lenient criteria, or you're a heckuva lot better than us, or you do a lot of missed approaches.


Now, whatever criteria it is that you use to maintain that centerline, or determine "established", whether it be measured in degrees or needle widths, or dots, or whatever, they don't apply to an arc. Arcs don't have a "centerline" per se. The only measure I can imagine that would apply to an arc would be measured in Nautical Miles DME. The DME might be an absolute number (say, 1 NM?) or it might be a percentage of the arc (10% of 12 would be 1.2?) or it might be based on aircraft category, or... well, I don't know. I just can't find anything to say, one way or another, what constitutes "established" on an arc for the purposes of beginning a descent.


Boy, I'd like to meet the guy that knows all about what the regs mean. Does he go by Avbug, by chance? .

Tony,

Your comments are well taken. Understand that I wasn't trying to say how one should fly things. I was just saying what the FAA has said about the term established. I'm still looking for the guy's name - I can't think of it to save my life. He'll answer e-mailed inquiries about the rules. He's well recognized as the rule guru in the FAA. Surely someone here knows who I'm talking about

A Squared? AvBug?

Oh, and about arcs, see A Squared's post. I'd forgotten about the 4 mile protection. An arc is treated like an airway from an airspace protection point of view and they do indeed have a centerline.

 

[TIS]

Found him! John Lynch! I'll keep looking for what I mentioned now.

TIS

 

[A Squared]

Found him! John Lynch! I'll keep looking for what I mentioned now.

TIS

TIS,

Unfortunately, John Lynch isn't going to be much help in ths situation. 2 reasons:

1.) He deals exclusively in maters involving pilot certification so he answers questions only about part 61 and 141.

2.) His answers have no official standing. while his FAQ pages contain some useful information, he has in the past given advice that was not in agreement with the FAA's official legal stance on the issue, as articulated by the office of chief counsel.

 

[Vector4fun]

Tony,
Oh, and about arcs, see A Squared's post. I'd forgotten about the 4 mile protection. An arc is treated like an airway from an airspace protection point of view and they do indeed have a centerline.

That may be true, I dunno, from a TERPs standpoint. But for plotting separation non-radar, we used 4 miles from an airway, and 5 miles from a DME arc...

 

[TIS]

1.) He deals exclusively in maters involving pilot certification so he answers questions only about part 61 and 141.

That wasn't always true and the stuff I read goes back a ways (1997 or so). It might also have been put out by someone else anyway.

2.) His answers have no official standing. while his FAQ pages contain some useful information, he has in the past given advice that was not in agreement with the FAA's official legal stance on the issue, as articulated by the office of chief counsel.

Also not completely accurate. DPEs are given guidance by OKC that his FAQ answers ARE indeed FAA policy. I realize that there may well be a difference between legal precedent and current FAA policy, but I think it's important to also reacognize that unless you've already gotten into the legal part of things, FAA policy is more important.

The reason is that FAA policy defines what the FSDOs will do with any sort of investigation. If an investigation finds that under existing policy a matter can be closed at the FSDO level then legal precedents don't matter.

This is getting pretty far afield now though. I think as a practical matter, establishment on a course is defined by whether you have course guidance - a needle off the case wall. In the case of an RMI things get a little stickier. 10° for VOR and 15° for an NDB are the nnumbers I've seen thrown around.

Whatever. I just let the FMS do it. If it looks good I go with it. If it looks bad I take over.

TIS

 

[TonyC]

I think as a practical matter, establishment on a course is defined by whether you have course guidance - a needle off the case wall. In the case of an RMI things get a little stickier. 10° for VOR and 15° for an NDB are the nnumbers I've seen thrown around.

Such practical application (needles, bearing pointers, etc.) has no place with a DME ARC, and it still doesn't give us a reference.







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[PA31Ho]

What is the reasoning behind the "1600 NoPT" on that 12DME Arc? What exactly is that telling me?

 

[TonyC]

What is the reasoning behind the "1600 NoPT" on that 12DME Arc? What exactly is that telling me?

Are you asking what's the reasoning behind the 1600 (obstacles) or the reasoning behind the NoPT (simplify the procedure) or are you asking what does "1600 NoPT" mean?

It means that the minimum altitude to which you may descend on that segment is 1,600 feet, and if you're flying that segment of the approach, you will NOT perform the procedure turn - - you will simply intercept the final and fly straight in.




Is that what you're looking for, or did I miss something?



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[PA31Ho]

Okay, I just wanted to confirm, that the 1600' meant that once you are cleared for the approach (even at the very beginning of the 12 dme arc, which is probably never going to happen), you can drop immediately to 1600' all the way to the OM. And the NoPT just simply says that you will not be making a procedure turn. Which, really doesn't need to be there in the first place right? I mean, looking at the layout it clearly shows that no PT is even needed to get to the LOC.


Thanks for the replies

 

[DC8 Flyer]

+/- 1 mile is in my AIM now. Let's go eat.

The only place I've ever seen +/- 1 printed is in the PTS.

I meant to say Initial Approach Segment, but I left out a '0'

Protected airspace on the initial segment is 4 miles lateral and a 2 mi. buffer.

Controllers can have aircraft on arcs 10 miles apart within 35 miles of the station.

None of this answers the question "What is established?"

Established on a DME arc is +/- 1 NM (DME) of the defined distance and within the published radials.

Now, I have never seen it, but I believe protected airspace on an arc is 4 miles, just like and airway and ATC is looking for +/- 2 miles, the +/- 1 mile is PTS stuff and is how GPS modes of OBS's show lateral deviation from the arc, so within 1 mile would be "needle alive".

 

[TonyC]

Established on a DME arc is +/- 1 NM (DME) of the defined distance and within the published radials.

Reference, please?








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[DC8 Flyer]

Okay, I just wanted to confirm, that the 1600' meant that once you are cleared for the approach (even at the very beginning of the 12 dme arc, which is probably never going to happen), you can drop immediately to 1600' all the way to the OM. And the NoPT just simply says that you will not be making a procedure turn. Which, really doesn't need to be there in the first place right? I mean, looking at the layout it clearly shows that no PT is even needed to get to the LOC.


Thanks for the replies

You are exactly right. Keep in mind that just because you are shooting an approach doesn't mean you have to stay on it if you get the airport in site. Say you get cleared for this approach at the very beginning of this 12 DME arc, and once you hit 1600 feet you breakout to +10 miles vis and see the field, simply call field in site and do the visual (IF ATC re clears you for the visual). Saves time and gas. I realize you are prolly training for your IFR ticket, but always keep that in the back of your mind, the earlier you can get down, the more likely you can get the field in site a little sooner.

 

[DC8 Flyer]

Reference, please?








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I have never been able to find one, except for the PTS standards, but as you know thats not defining established simply a tolerance. Now, the Garmin and Bendix GPS units I have used always used the 1 mile scale on the CDI needle for arcs, so thats where I get the 1 mile, maybe its wrong, but seems a good place to start.

Keep in mind the last time I shot a DME arc was 2001.

 

[TonyC]

Keep in mind that just because you are shooting an approach doesn't mean you have to stay on it if you get the airport in site. Say you get cleared for this approach at the very beginning of this 12 DME arc, and once you hit 1600 feet you breakout to +10 miles vis and see the field, simply call field in site and do the visual (IF ATC re clears you for the visual). Saves time and gas.

Do that on the ILS RWY 3 at Casper from the Muddy Mountain 29 DME arc at say, the 180 radial or so, and good luck with the high terrain. I wouldn't recommend it.

Sometimes the potential savings in time and gas is not worth the potential threat to safety.


Just an opinion...




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[DC8 Flyer]

Do that on the ILS RWY 3 at Casper from the Muddy Mountain 29 DME arc at say, the 180 radial or so, and good luck with the high terrain. I wouldn't recommend it.

Sometimes the potential savings in time and gas is not worth the potential threat to safety.


Just an opinion...




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Of course, there are exceptions to everything, just like doing a circling approach at nite in Aspen, when it was authorized, just cause you can, doesn't always make it a good idea. Thats where judgement comes in.

 

[stagger]

Don,t make this so hard

As soon as you cross over the holding fix to go into a holding pattern regardless of holding pattern type I say to atc...BIG DOG XXX is established in holding.

 

[TonyC]

As soon as you cross over the holding fix to go into a holding pattern regardless of holding pattern type I say to atc...BIG DOG XXX is established in holding.

Well, it may not seem hard to you, but you've got it wrong.

Say, "BIG DOG XXX is ENTERING holding"






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[Singlecoil]

Well, it may not seem hard to you, but you've got it wrong.

Say, "BIG DOG XXX is ENTERING holding"






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Tony is right. All my IFR training was in a non-radar environment. You would report entering, then they would say, "Roger, report established."

 

[A Squared]

And the NoPT just simply says that you will not be making a procedure turn. Which, really doesn't need to be there in the first place right? I mean, looking at the layout it clearly shows that no PT is even needed to get to the LOC.

Yeah, it really does need to be there. In non-radar ops, if it doesn't say "no PT" you do the procedure turn, even if it looks like you don't need to do it.