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Cleared for the ILS....

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DLconnection

Well-known member
Joined
Dec 1, 2001
Posts
121
If I was being radar vectored for an ILS approach and was cleared for the approach while being on an unpublished route.... I know that I would have to remain at my present altitude until established on a published segment of the approach plate. Then I can descend on down to whatever alt. are published.

My question is.... If I was being brought in through a feeder route and was cleared for the approach, lets say, 10 miles out. Could I descend down to the MEA that is published on that feeder route at that time? Also do I need to wait until I am at whatever distance is published on that feeder route before I descend. I'm assuming .... yes. These feeder routes are considered TRANSITION segments of an approach, transitioning me from the enroute structure to the IAF of the approach. On these feeder routes..... would I be considered "ESTABLISHED ON THE APPROACH" Which would allow me to descend?
 
If you are cleared for the approach, you may descend to any altitude published on the approach or elsewhere. You could even descend to the mea on an airway, if they cleared you that far out and you were still above it.
 
If cleared for an approach while on an airway you could descend to MEA then when within 22nm of the navaid down to MOCA.


"My question is.... If I was being brought in through a feeder route and was cleared for the approach, lets say, 10 miles out. Could I descend down to the MEA that is published on that feeder route at that time? Also do I need to wait until I am at whatever distance is published on that feeder route before I descend. I'm assuming .... yes. These feeder routes are considered TRANSITION segments of an approach, transitioning me from the enroute structure to the IAF of the approach. On these feeder routes..... would I be considered "ESTABLISHED ON THE APPROACH" Which would allow me to descend?"


Say the navaid on your airway was also the navaid begining a feeder route, then you could further descend the the minimum altitude published on the approach plate. (The term MEA is associated with altitudes on the "E"nroute chart.) The distance published is the length of the route between navaids so you would have to be within this distance to be on the route at all. Since a feeder route transitions you from the enroute structure to the IAF you wouldn't be considered established because you haven't crossed the IAF. Also, a feeder route segment can be over 30 miles in length which puts you outside the terminal area and way off the approach plate.
 
>>>>Say the navaid on your airway was also the navaid begining a feeder route, then you could further descend the the minimum altitude published on the approach plate.

Yes, that's what those altitudes are for. Once you've left the airway and are on a transition, it wouldn't make sense to continue maintaining the MEA (or MOCA) for the airway you *were* on. You'd maintain the altitude for the transition segment. In fact sometimes a minimum altitude for a transition is *Higher* than the MEA of the airway you just exited. IN such a case, maintaining the previous MEA/MOCA might get you killed.

"established on a published portion of the approach" means the transition routes also, they are published, they are part of the approach.

I'm not sure what you're getting at with your questions about the distances and such.

All transitions start with an identifiable fix.

It may be an intersection, A DME fix on an airway, a Navaid, or a RNAV/GPS waypoint. THat's the start of the transition. The fix may be depicted on the approach plate, or it may be outside the area on the chart, but the principle is the same, it satrts at an identifiable fix. Once you hit the fix and start mavigatiing hte transition, the published altitude is applicable.


DOes that answer your question?
 
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["established on a published portion of the approach" means the transition routes also, they are published, they are part of the approach. ]

Sure they're published but they're not part of an instrument approach. What part of the approach do you consider it part of? I'm familiar with the 4 segments of an instrument approach and a feeder route isn't one of them.

If you were stable or fixed on a feeder route you could be considered "established" on that route, but you would not be considered "established on the appraoch."
 
If you own a FAR/AIM look under the following:

5-4-6. Approach Clearance

Read the part that is in BOLD letters.

A Squared is NEVER wrong
 
Nobody is NEVER wrong, to include me.

AIM 5-4-6 states: "When cleared for the approach, published off airway (feeder) routes that lead from the en route structure to the IAF are part of the approach CLEARANCE."

What you referenced is with regard to an approach CLEARANCE, NOT the elements of an approach. Maybe it's semantics, which are important in aviation, but part 97 defines the segments of an approach as: Initial, Intermediate, Final, and Missed. The approach begins at the IAF and not prior. If you can show me something to the contrary I would love to learn about it. But your response doesn't and shows your lack of understanding.

There's no question that if on a feeder route and "cleared for the approach, published off airway (feeder) routes that lead from the en route structure to the IAF are part of the approach CLEARANCE". Just as a radar vector would be part of an approach CLEARANCE. It does NOT make it part of an instrument approach.

I'll ask you then, what part of an instrument approach do you consider it part of?
 
FNG,

>>>>Nobody is NEVER wrong, to include me.

While I appreciate "Check's" vote of confidence, I agree, I'm certainly wrong my share of the time. I would much rather be shown to be wrong than to be the source of incorrect information.

As far as I can see we are in agreement that you may descend to the altitude depicted on the feeder route, as soon as you are on the feeder route. Correct?


OK, as far as the semantics go, you say that Part 97 lists the segments of an approach. Correct, it does, but it falls short of saying that anything not listed is not a part of an approach. Part 97 also incorporates the TERPS by reference. If you take a look at the TERPS, You will see that for each type of approach there is a section defining standards for each type of approach, and each one of those sections, for each type of pilot nav approach is divided into 5 parts titled: feeder routes, initial approach segment, intermediate approach segment, final approach segment, and missed approach segment.
This grouping seems to suggest a feeder route being considered a part of an approach.

We can go to the AIM and find the definition of Instrument Approach Procedure which reads:

INSTRUMENT APPROACH PROCEDURE- A series of predetermined maneuvers for the orderly transfer of an aircraft under instrument flight conditions from the beginning of the initial approach to a landing or to a point from which a landing may be made visually. It is prescribed and approved for a specific airport by competent authority.

which doesn't include feeder routes .... but wait !!! That doesn't include missed approaches either, does that mean that the missed approach segment isn't part of the instrument approach??????

Well, we can look below that to the ICAO definition
which reads:

INSTRUMENT APPROACH PROCEDURE [ICAO]- A series of predetermined maneuvers by reference to flight instruments with specified protection from obstacles from the initial approach fix, or where applicable, from the beginning of a defined arrival route to a point from which a landing can be completed and thereafter, if a landing is not completed, to a position at which holding or en-route obstacle clearance criteria apply.

This definition includes both the missed approach segment and feeder routes as part of an instrument approach procedure.


So which definition do we use? The U.S. is, after all, a signatory nation to ICAO, does "our" definition rule over the ICAO's? If so, do we have to go back and correct all those references which list the missed approach segment as a part of an instrument approach procedure? Or, is the U.S. definition anachronistic in light of the newer, more complete ICAO definition?

Certainly, the FAA is not immune to publishing anachronistic information, Coincidentally, in Part 97.10 it states ".......charts prepared for the use of pilots by the US Coast and Geodetic Survey..."

Never mind that Government charts have been published by NACO for several years, the U.S Coast and Geodetic Survey hasn’t existed as a government agency for over 3 decades. In light of this, one might be cautious using Part 97 as a source of absolute truth.


regards
 
FNG,

After re-reading this entire thread I see the point you were making. I incorrectly assumed you were saying you could not descend on the feeder route.

I think you are just looking to split hairs with the orginal poster of this question but you are 100% correct that the instrument approach begins at the IAF.

My apologies
 

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