When can you descend

[midlifeflyer]

And, that question remains unanswered...

Only if you want it to be.

==============================
ESTABLISHED - To be stable or fixed on a route, route segment, altitude, heading, etc.
==============================

seems about as simple and understandable as it can be.

 

[philo beddoe]

When you hit the VOR and start to turn, you are established on that segment. That is why they give you 4 or more nm of protection in the primary area alone.

Check out that plate for appleton again. Why the procedure note if being established on the RADIAL was always a condition of descent?

Being established on a radial and being established on a segment of the approach can mean two different things.

To be fair, I believe that the military requires their pilots to be firmly on the radio prior to descent, but that does not prove anything about civilian regulations.

Point of order: If you are established on an airway that bends sharply at a vor and overshoot the new radial, are you temporarily not established, requiring you to consider the sector altitude? I think not.


Here's a question for all of you:

When do you report "established in the hold"?

A. When you first cross the holding fix.
B. When you turn outbound
C. After completing the entry on your first inbound leg
D. After you get the 1 min inbound all worked out


And to clarify the point again, you may descend regardless of the direction from which you arrive at the IAF. There is no "wrong" side when turning outbound, so no worries about overshoot. Personally, I lead the turn by about .7-.9 dme if available jsut to make a clean intercept. But then, I usually make a hold-type entry instead of the standard PT, since it is sompler and a more elegant solution than the dull axe that is the PT.

Caveat: Hold type entries do not work as well if there is a lot of altitude to lose outbound or inbound.

 

[TonyC]

If you are cleared for a vor approach (full procedure) when can you descend to the outbound leg altitude. Is it once you cross the vor or do you have to be established on the outbound radial prior to descending.

Thanks

It's rather amusing to see all the twists and turns the answer to this simple question can take.

To begin with, let's assume that ACAFool intended to specify a Procedure Turn type of Instrument Approach Procedure, as opposed to a teardrop approach or procedure track of some sort. If so, then there IS no "outbound radial." The procedure turn has an INbound Course, and a manuevering side.

Examine the question further, and notice the poser asks a multiple choice question:

Is it (A) once you cross the vor or (B) do you have to be established on the outbound radial prior to descending.

Since we've already established that there is no outbound radial, the answer must be (A)!







.

 

[bafanguy]

Midlifeflyer,


Okee, dokee... was just trying to have a little shoptalk with fellow aviators on an interesting technical issue. MEA CULPA !!! ...oops, mea culpa...

I still seriously doubt a dictionary definition suffices for an area where things are so carefully defined ( legally and technically ) as they are in instrument flying. But...that's just one guy's opinion.

ASquared seems to have a handle on the TERPS stuff.

 

[midlifeflyer]

I still seriously doubt a dictionary definition suffices for an area where things are so carefully defined ( legally and technically ) as they are in instrument flying.

In other words, it depends on what the meaning of "is" is?

That English thing? There's an awful lot of it going around.

ATC: Climb and maintain 8 thousand feet.
Pilot: What do you mean by "feet"? I can't find a definition in the FAR! Nor can I find definitions for "climb", "maintain", "eight" or "thousand". How do you expect me to know what to do?

 

[Uncle Sparky]

Now THAT'S funny!

Obviously, there are tolerances built into the system since neither people nor navigational aids are perfect

I think the answer is hinged on this statement. The reason that no defined numbers or tolerances are published regarding what is ESTABLISHED is because, as it was stated, it's human nature to bend the rules. So when a particular approach is developed, the courses, routes, and altitudes have to be established with a degree of "fudge factor".
I used to tell my students to not fixate on hold entries, "you're gonna be disregarding aviation rule NO.1, you'll be trying to hold the "Vulcan Peace Sign" over the DG with one hand and have a note pad, pencil and caculator in the other and in the mean time, will be flying into some mountain because you've blown past the holding fix."
If I am approaching the holding fix directly from the direction of the inbound leg and decide to do a PARALLEL entry instead of direct "there won't be an FAA helicopter there waiting to give me a ticket!"
In my opinion, the question has been answered. You may descend once Established(as defined), unless other specifics of the particular approach have otherwise been published(as has been discussed).

 

[lawfly]

The relevant crash was in the 70's, an arrival to Dulles, I believe. 727 or -9. Eastern? Accident aircraft was cleared for approach while still a ways out. And was not yet 'established' on any published segment of the approach procedure. And terminology back then was simply "cleared for the approach". Descended into terrain.
Once cleared the approach, can descend when "established" on published segment of the approach procedure for which a lower altitude is published. "Established" is not precisely defined anywhere by reference to instrument indications and will depend in part upon intercept angle, aircraft speed, wind speed/direction, etc., which in turn will affect the speed at which the needle is moving/centering, assuming there is a needle/CDI involved. Also, on whether it's a localizer or a less sensitive directional system. The biggie here I think is the published approach segment.
The Terminal Arrival Area descriptions in the AIM look interesting. (e.g. Figures 5-4-7, 5-4-8).

 

[Uncle Sparky]

..............."Established" is not precisely defined anywhere by reference to instrument indications and will depend in part upon intercept angle, aircraft speed, wind speed/direction, etc., which in turn will affect the speed at which the needle is moving/centering, assuming there is a needle/CDI involved. Also, on whether it's a localizer or a less sensitive directional system. ................

That's the point that I was trying to make with my obtuse FAA helicopter scenario.
I wouldn't want to intentionally make a 210 degree turn away from the fix towards the the "unsafe" side of the holding course. On the same token, there aren't complete dimensions for a holding 'racetrack', beyond leg distance and overall approach tolerances(MSA, MOCA, "do not exceed XX DME" notations) either. If I DO have a strong tail wind as I cross the fix or if I enter the hold from the direction of the dividing line for the parallel/direct sectors or am unfortunate enough to encounter both elements at once.........I may be flying a minute or so out in "unsafe side" land before I can become ESTABLISHED.

I may allow for a degree of tolerance as far personal standards for hold entries but if this same hold is associated with an approach, of course I will lead a radial but I'm not going to DESCEND until the needle is centered.

 

[100LL... Again!]

That is a common technique, but is not required. Most folks I know use a live needle.


Me, I use station passage plus a turn outbound.

4nm is a lot of real estate.

 

[igneousy2]

Now THAT'S funny!

I used to tell my students to not fixate on hold entries, "you're gonna be disregarding aviation rule NO.1, you'll be trying to hold the "Vulcan Peace Sign" over the DG with one hand and have a note pad, pencil and caculator in the other and in the mean time, will be flying into some mountain because you've blown past the holding fix."
If I am approaching the holding fix directly from the direction of the inbound leg and decide to do a PARALLEL entry instead of direct "there won't be an FAA helicopter there waiting to give me a ticket!"

Your student's will be fine unless they happen to be in a simulator for an airline interview.

I do agree with what you are saying, I am amazed that anyone can actually draw a hold entry out while still keeping the shiney side up. I have never drawn a hold in my life except as a flight instructor during initial holding ground.

 

[ekuflyer]

Must be on a parallel or intercept heading after positive station passage.

 

[nosehair]

Midlife...


What definition YOU ( emphasis again...) are happy with means nothing to the FAA. And I guess that's my point and what makes questions like this so interesting for discussion.

Am I asking the definition of "established" ?? Well, yes Sir. I don't know how to be any more clear about that. It was the gist of the original question.

And, that question remains unanswered...

bafanguy, the question has been answered, as well as it ever will, by midlife and Asquare. You are not going to find a specific definitive point, like,say, the MAP, or FAF, etc. "Established" depends on knowing your position relative to the "maneuvering zone" within the approach construction. Knowing something about the construction of airspace and obstacle clearance as outlined in TERPs will show you how much lateral and verticle distance you may be away from "centerline" and still be in the "maneuvering zone" for turns and descents. Each approach is different, so the "commonly accepted" methods of insuring you are well within those lateral and verticle distance descriptions of the airspace allowed for the approach is to use the nav instruments we have, ie., "needle off the peg", or "3/4 scale". These are not FAA official definitions of the word "established", but are standardized tolerances for demonstration of pilot certification performance standards. If you can determine that the outbound segment allows, for example, one mile lateral distance from the radial at the vor "abeam" position, and four miles lateral distance from the outbound radial at the ten mile limit, and you have a GPS display that shows you are within this "maneuvering zone" for obstacle clearance at the PT altitude, then you may descend. You are "Established" within this maneuvering zone. If you're still flying vor needles, the commonly accepted method of insuring you are "in the zone" is to wait for some needle movement. But that is a technique - not a regulatory requirement.

 

[bafanguy]

nose,


Okee dokee...

 

[100LL... Again!]

Exactly, well put.

I salute your nosehair.

 

[Atccfi]

Established inbound

I was always told if you were outbound and turning inbound on the approach once the needle "came alive" you were established.... have I always been wrong? ATCCFI

 

[100LL... Again!]

Once the needle is alive, you are inside the area protected by the trapezoid.

Go ahead and descend.

As I matter of pratice, I wait until close to 1/2 scale just to ensure that it is not a transient movement of the needle.

 

[Tinstaafl]

I can't answer for FAA definitions however Australia & the UK, operating under ICAO's PANS-OPS, define 'established' as 5 deg for NDB approaches, half-scale deflection or equivalent for VOR & ILS approaches. This means that ILS & localiser approaches have a tighter tolerance WRT 'establised' than do VOR or NDB approaches.

Originally CDI & GS accuracy was specified as 2 1/2 dots however this relied on a presumption of 5 dots either side on the display. OK originally since that was how every display was done. Not so good once other dotted scales started to be used so it was eventually changed to the half-scale terminology. This also applied to test standards for licences & ratings.

For a while Australia's documents specified both the outbound & inbound descents could only be commenced once established - with established defined as I mentioned above. I seem to recall that the descent allowance has been changed in recent times so that it only applies on the inbound course ie descent outbound is now allowed as soon as the a positive indication of outbound is seen. There have been all sorts of changes in Oz procedures over the last 20yrs as they moved to various ICAO revisions so I may have the outbound descent conditions a bit backwards ie it might have been 'descend after positive outbound determined' and is now 'only descend outbound once within 5 deg'. I certainly remember it both ways but can't quite recall which was first. They may even have been one way, gone the other, then switched back.

Anyway, that's the ICAO 'take' on things.

 

[100LL... Again!]

Good point to bring up ICAO - I had read that somewhere and I think that it makes sense to use that for domestic ops as well. (As a matter of practice rather than a matter of reg)

 

[nosehair]

so I may have the outbound descent conditions a bit backwards ie it might have been 'descend after positive outbound determined' and is now 'only descend outbound once within 5 deg'. I certainly remember it both ways but can't quite recall which was first. They may even have been one way, gone the other, then switched back.

...uuuh, is that Kerry talkin'?

 

[Tinstaafl]

Nah....that's Australia's Civil Aviation Safety Authority for you, formerly Civil Aviation Authority, formerly Department of Transport & Communications, formerly Department of Transport, formerly Department of Aviation, formerly Department of Civil Aviation......and that embraces the 21 years I've been flying.

Any surprise all the procedural & system deckchairs have been shuffled multiple times as well?