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Fix from which an approach begins...


crashed_05
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We had so much fun with my last IFR question, I thought I'd ask another on here.

I know that a feeder route is included in an approach clearance. If cleared for your approach, you may commence your descent at the feeder fix. (AIM 5-4-6)

But, is a feeder fix considered a fix from which an approach begins when we're talkin about when to leave the clearance limit under 91.185? I have always been taught that a fix from which an approach begins is just the IAF, but I recently began to think about the feeder route and was curious if it was considered the begining of an approach.

Can't wait to hear the responses!

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A clearance must contain the following elements, clearance limit, route, altitude, and efc if required. A feeder fix meets all these requirements, and is a portion of an approach, therefore it qualifies as a fix from where the approach begins. Another definition of initiation of approach is, leaving the highest altitude of any of the published approaches for that destination. At least that's the way I understand it. Excellent question by the way, and so was your last topic, although it never really got resolved satisfactorily, it did generate quite a bit of interesting discussion, and entertaining conflict.

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A feeder fix meets all these requirements, and is a portion of an approach

 

 

That's correct.

 

 

If a feeder route to an IAF is part of the published approach procedure, it is considered a mandatory part of the approach.

 

A pilot must begin a Standard Instrument Approach Procedure (SIAP) at the IAF as defined in Part 97. Descent gradients, communication, and obstruction clearance, as set forth in the U.S. Standard for Terminal Instrument Approach Procedures (TERPs), cannot be assured if the entire procedure is not flown.

 

Legal Interpretations & Chief Counsel's Opinion

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But, is a feeder fix considered a fix from which an approach begins when we're talkin about when to leave the clearance limit under 91.185? I have always been taught that a fix from which an approach begins is just the IAF, but I recently began to think about the feeder route and was curious if it was considered the begining of an approach.

 

The point of 91.185 is that you have two choices when arriving at your clearance limit; leave it at your EFC time (expect further clearance) if given, or if no EFC time, then leave to arrive as close as possible to your ETA (as filed, or ammended).

 

The guiding limitation isn't whether the feeder fix begins an approach,but whether you've been issued an EFC time or not. If you have an EFC time, that's what limits you as to when to leave your clearance limit. Otherwise, the intended guidance is to get you arriving at your destination as close as possible to either your filed ETA, or your ETA as ammended by ATC or as updated by you and thus amended.

 

Most of the time your clearance is "cleared to destination via..." and your destination is your clearance limit. This isn't always the case. You may receive clearance limits or amended clearances enroute. You may receive holding or clearances to a specific waypoint.

 

Regardless of whether your clearance limit is a fix from which the approach begins or one that isn't, you're either bound by an EFC, or by your ETA. Whether you're considering the feeder fix the beginning of the procedure or the IAF, you should plan on crossing either one with such timing as to get you to the destination as close as possible to your ETA.

 

A feeder fix can be part of an approach procedure, but it not always part of the procedure, and your clearance may or may not include a feeder fix. If your clearance limit was to the feeder fix, then you may operate with it as part of the procedure. However, you may have been cleared direct to the IAF, or may have filed using the IAF rather than a feeder fix. If your clearance limit was prior to the IAF, and your flight plan or amended clearance included the IAF and not the feeder fix, you'd be expected to leave the clearance limit at your EFC, or in lieu of an EFC at a time that will allow you to proceed to the IAF and descend and approach to arrive at your ETA.

 

You should also get and stay VMC if possible, land as soon as practicable, and notify ATC, because the airspace will be locked up pending your location until you do so, or until you're no longer available to tie up that airspace.

 

14 CFR 91.185 specifically concerns lost communication, and 91.185©(3) involves leaving the clearance limit. It doesn't really matter if the IAF is the clearance limit or the feeder fix, nor whether the procedure begins at the IAF or at the feeder fix. Either way, you leave at your EFC, or in lieu of that, at a time that puts you a position to arrive as close as possible to your ETA.

 

You'll find additional Chief Legal Counsel interpretations on the subject:

 

http://www.faa.gov/about/office_org/headquarters_offices/agc/pol_adjudication/agc200/interpretations/data/interps/2010/Turri.pdf

 

http://www.faa.gov/about/office_org/headquarters_offices/agc/pol_adjudication/agc200/interpretations/data/interps/2011/Tuuri.pdf

 

http://www.faa.gov/about/office_org/headquarters_offices/agc/pol_adjudication/agc200/interpretations/data/interps/2010/Olshock.pdf

 

http://www.faa.gov/about/office_org/headquarters_offices/agc/pol_adjudication/agc200/interpretations/data/interps/2009/Desselles_Jr.pdf

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Avbug's discussion, which I appreciated, leads me to mention a pet peeve I have while operating on a clearance under radar contact. ATC will often use heading changes to deconflict traffic and ensure proper separation. Out of nowhere they will issue a directive "123AB turn left 30 degrees", or something very similar. They may or may not include "for your descent", or "for your climb". But what they almost NEVER include is an EFC. To not ask for how long on that heading, or ask for an EFC, then going lost comm can easily lead to pigs in space, courtesy of Jim Hansen and his muppets.

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A feeder route is a published part of the approach, but the approach starts at an IAF.

In the theoretical case that the clearance limit is not an IAF and no EFC time has been issued and the aircraft arrives earlier than planned the pilot should continue past the clearance limit and hold at the IAF until ETA.

For several reasons this practically never happens. Radio failures are rare, a clearance limit enroute is rare and a pilot should not accept that clearance limit without EFC.

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They may or may not include "for your descent", or "for your climb". But what they almost NEVER include is an EFC. To not ask for how long on that heading, or ask for an EFC, then going lost comm can easily lead to pigs in space, courtesy of Jim Hansen and his muppets.

 

You can ask for a reason for the vector, but it's generally given. "For your descent" or "for your climb" isn't the reason for the vector, but it's a short explanation. Generally if there's no traffic involved and you're being vectored for a climb or descent, it's because you aren't climbing or descending fast enough. Otherwise, it's for traffic separation or flow. If it's for weather, you'll be told. You can always ask the reason for a vector. In the US, controllers are very good and very professional, and you'll seldom be vectored without an explanation (unless busy). When arriving in the terminal area), you can often expect vectors off the arrival at some point, to an approach or to a runway.

 

In the event of lost communication during vectors, proceed directly from the point where communication loss is realized to your next point, as you were doing at the time you were issued the vector.

 

AIM 6-4-1 provides a valuable clue as to where you stand with lost communication:

 

6-4-1. Two-way Radio Communications Failure

a. It is virtually impossible to provide regulations and procedures applicable to all possible situations associated with two-way radio communications failure. During two-way radio communications failure, when confronted by a situation not covered in the regulation, pilots are expected to exercise good judgment in whatever action they elect to take. Should the situation so dictate they should not be reluctant to use the emergency action contained in 14 CFR Section 91.3(B).

b. Whether two-way communications failure constitutes an emergency depends on the circumstances, and in any event, it is a determination made by the pilot. 14 CFR Section 91.3(B) authorizes a pilot to deviate from any rule in Subparts A and B to the extent required to meet an emergency.

 

Generally in the case of a vector, you can expect to be told how long the vector will be in minutes or miles. Not always, so knowing what to do while on that vector is important. When you realize that you're lost comm or NORDO, squawk 7600. If your cleared routing was on an airway, return to the airway. If you were on vectors in the terminal area for an approach, proceed from the point of comm failure to the next fix in your clearance. This is a time when you really need to be aware of terrain and obstacles and the altitudes applicable to your area. If you were below the published altitudes for the terminal area or procedure, and at the controllers MVA (minimum vectoring altitude; values that aren't published where you can locate them in the cockpit), you may be in the proverbial hurt locker if you don't recognize a lost comm situation soon and act intelligently.

 

You may already be below the MSA and below various altitudes for a procedure, when you lose communications. Be aware before you get to that point what the applicable altitudes are. Know what you need to do to get back on course or to the fix which defines the approach you'll be using, and what you'll need to do to address terrain and other hazards, in the event that communication with ATC ceases. Be prepared to fly the full procedure. There are plenty of areas abroad, and certainly within the US, where you simply cannot stay on a vector for an extended period of time. Mountains and other concerns are immediate, and final. Always make a note of what you may have to do if you're no longer in contact with ATC, and you should always have a plan as to what you're going to do in the event that ATC doesn't get with you.

 

If you don't hear from ATC, especially when approaching a clearance limit or when approaching the inbound course on an approach, query them. Hey, guys, I'm about to blow right through final, did you forget about me? It happens. There are approaches in the US in which going full scale deflection on a localizer will put you into terrain. It's fatal. You can't afford to go too far on a vector in some areas, without taking corrective action on your own. When departing Anchorage, for example, there's a lot of room, but one would be very foolish to continue indefinitely on the vector. The Anchorage 4 departure is all vectors; takeoff and turn, there's a heading, and from there, it's vectors. If lost communications occur, the departure procedure has instructions, as do most departure procedures. Many approaches do, too. However, there are many circumstances when flying when vectors aren't tied to printed instructions.

 

Enroute, go directly from the point of comm failure to the next fix on your planned route, or cleared route, or the route you've been told to expect. Use the highest altitude for that particular sector of your filed altitude, cleared altitude, or that which you've been told to expect.

 

For several reasons this practically never happens. Radio failures are rare, a clearance limit enroute is rare and a pilot should not accept that clearance limit without EFC.

 

In the perfect world, yes. In the working world, not so much. Clearance limits are common; crossing any international FIR (flight information region) boundary it's possible, as well as crossing international borders, one often has a clearance up to the border, then obtains another when going beyond. We see it in Afghanistan regularly; the clearance gets us to a point in space, with nothing beyond. After that, it's up to Kazakhstan or Pakistan or other to provide us further. In domestic airspace in the US, ATC is considerably more advanced and unified, and this isn't a problem for the most part.

 

Clearance limits don't always come with an EFC. In fact, an EFC is generally only issued when holding. When filing to a busy terminal area, while your flight plan may include only the last enroute fix and then the destination, arrival procedures will always be in effect. You won't know when approaching Miami, for example, which of the 75 or so arrivals and approach procedures will be in use; not until you're close. You may be cleared to the last fix on your flight plan, and but that doesn't give you clearance along any routing to the airport; in fact, if you were cleared as filed, and you included only the last enroute fix and then the destination as your routing, now you're in a position to be cutting through a LOT of traffic while making a beeline directly for the airport (A good reason to include the departure and arrival in your routing when you file a flight plan).

 

Crossing into international airspace, your clearance may be to a point in space at the border, or it may be an initial clearance all the way, but you should usually expect a re-clearance as you approach the border. Not always, however. Some locations, one must negotiate each crossing in advance on a separate frequency (such as calling ten to fifteen minutes before crossing the border), and even then without pre-arranged overflight authorization, one may end up holding at the border or being given vectors around the country. That happens.

 

Radio failures are rare, but not too rare. Especially in piston aircraft, small, weak alternators and generators are subject to frequent failure; you may or may not have electrical power from the alternator or battery to run radios, transponder, etc. In the case of purely a communications failure, you may not be able to transmit, but only to receive, or visa versa. You may have a perfectly functioning transponder, and can squawk 7600. In an electrical failure situation, however, you've just lost your ability to transmit and receive, once the power goes dead, and that includes the transponder. If you've lost electrical, you may need whatever electricity you have left for functions as you get closer to landing, and may wish to turn off high-draw items like the transponder. Therefore, assuming that ATC can still see you won't necessarily work.

 

Bear in mind that ATC wants you on the ground or accounted for as soon as possible. Some feel that they should go to the IAF and wait there until their ETA, holding as long as necessary. ATC does not want you holding in their airspace for an hour, tying up traffic and presenting a hazard to aerial navigation. ATC would much rather you be on the ground, whether it's landing while you have a VFR opportunity, or getting to a fix, flying the procedure, and getting on the ground.

 

Holds generally represent a clearance limit, and come with an EFC. Not always, however. Holds can occur enroute, or they can occur on the arrival or approach in a terminal area. I've had holds in the middle of nowhere, over Kazakhstan, and I've had them while flying the approach procedure in Chicago. I've even been told "hold right there" while on the ILS in Riyadh, inside the GSIA/FAF, on relatively short-final; orbit and hold, while the king and his precession of Blackhawks and other equipment turned onto the approach ahead of me, and landed. Once they were clear of the runway, I was cleared to proceed and land. It happens.

 

Not all clearance limits come with an EFC, just as not all vectors come with a reason, a time, or a distance. You should always plan, or have a plan, to act on your own in the event that you never hear from ATC again. Approach the entire flight this way. Ask yourself what you need to do to operate safely from here to there,and keep asking yourself that question every minute throughout the flight. What do I have to do now? And how about now? Now? Keep asking. Your flight is dynamic, it changes, and much of the country is populated, and has busy airspace. Much of it is considered mountainous, and where it's flat, there are big radio towers and other hazards. Stay oriented, know where your course and fixes are, and know what altitudes you'll need in the event nobody else is watching out for you. It can happen at any time.

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If the clearance limit is not a fix from which an approach begins, leave the clearance limit at the EFC time if one has been received, or if none has been received, upon arrival over the clearance limit, then proceed to a fix from which an approach begins and commence descent or descent and approach as close as possible to the estimated time of arrival as calculated from the filed or amended (with ATC) estimated time en route.

 

Execute the entire approach procedure commencing at an IAF or an associated feeder route as described on the IAP chart. In other words fly it AS PUBLISHED.

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