When to descend?

[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.







.

 

[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?



.

 

[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