Starting approach at intermediate fix?

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800man
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Starting approach at intermediate fix?

Post by 800man »

Sorry for all the ifr questions.
Question, can you start a gps approach from the intermediate fix instead of one of the iawps?

In the States there is a provision saying you can, as long as there isn't more than a 90 degree turn to final.
I can't find anything in the TC aim about it in Canada however. There is a blurb in the aim (9.16) stating you can go "straight in" from an IF but it seems to be talking more about just in lieu of a procedure turn for a traditional approach.

I know of a few approaches that would be a bit if a detour to go to an iawp instead of straight to the IF then straight in.
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Re: Starting approach at intermediate fix?

Post by Oxi »

Small tip, if you aren't flying or going to fly in the US, I wouldn't bother with learning their rules until needed.

Yes you can do what you've posted. If it's going to be a tight turn and farther away why bother? You can go to the FAF, IAWP, MAP etc etc
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Re: Starting approach at intermediate fix?

Post by watermeth »

think twice before cutting corners.
depending on your aircraft which will have increasing performances as your career proceeds, you might have to think twice before cutting corner. you also have to consider your avionic eqpt in the equation.
unless vfr, just do the published procedure and you will always touch down wether or not you are familiar with the airport.
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Re: Starting approach at intermediate fix?

Post by leftoftrack »

+1 on doing anything that may cause more stress than what it will save you. Set the FMS up to do the most normal predictable stable approach that you can. No sense in trying to save time and money and going missed because you were unstable. If it were important to an employer they will have RNP approaches that can reduce track miles. The only wild card is ATC changing runways on you. You talk to anyone in a transport category airplane and the worst thing that happens on a regular basis is runway changes
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Re: Starting approach at intermediate fix?

Post by eh3fifty »

The only regulation that I know of that relates to this is CAR 602.127, "Unless otherwise authorized by the appropriate air traffic control unit, the pilot-in-command of an IFR aircraft shall, when conducting an approach to an aerodrome or a runway, ensure that the approach is made in accordance with the instrument approach procedure."

An "instrument approach procedure" starts with the IAF, proceeds to the MAP, and then to the MAHP. My take on that is that, when you are cleared to fly a specific approach, you must fly the instrument approach as stated on the plate by going to the IAF and continuing all the way to the MAHP and holding at that point until you receive further clearance or you see the runway and have clearance to land. If you want to do anything other than that, you need to get clearance from ATC to do so when in controlled airspace.

When you're in uncontrolled airspace, there is no ATC and you can do whatever you like with regards to joining the IAP. You still need to abide by the altitudes and other restrictions on the plate.

You have to be careful when doing this though. In the prairies it's generally OK to go direct the IF and inbound but if you're around mountainous terrain, the difference in altitude between the minimum sector and the intermediate segment altitude might be quite significant and you would be better off starting at the IAF/IAWP. If you have an FMS make sure you're familiar with it - you don't want to get into a "what's it doing now?" situation when you're inbound on the approach.
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Re: Starting approach at intermediate fix?

Post by Liquid Charlie »

The other issue is the hardware -- some of the more common GPS units such as Garmin are not smart enough to accomplish approaches started inside the IF -- their little silicon brains sometimes just refuse to do what you think they should do -- I never had issues with the Universal but Garmin has surprised me several times ----- know your hardware --
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Re: Starting approach at intermediate fix?

Post by Big Pistons Forever »

Liquid Charlie wrote:The other issue is the hardware -- some of the more common GPS units such as Garmin are not smart enough to accomplish approaches started inside the IF -- their little silicon brains sometimes just refuse to do what you think they should do -- I never had issues with the Universal but Garmin has surprised me several times ----- know your hardware --
In the Garmin G430/530 series you can activate any leg of the approach. I have been cleared the full LNAV and then been vectored to intercept the final approach course just outside the FAWP. When this happens you simply skip down the list of waypoints on the flight plan page with the cursor, highlight the end of the leg you wish to activate and double click the direct to key.
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Re: Starting approach at intermediate fix?

Post by sstaurus »

I would agree with the majority here, the most detail I've found on this straight from the AIM:

"The pilot has the option of proceeding by the route so cleared by ATC in a previous clearance, by any published transition or feeder route associated with the selected procedure, OR by a route present position direct to a fix associated with the selected instrument procedure".... yadda yadda.. and further more the pilot is supposed to advise ATC of the type of route and or procedure to be flown (which mostly I find they don't care).


In other words, any fix associated with the procedure may be chosen. At least that's my interpretation, subject to the caveats mentioned by others above.
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Re: Starting approach at intermediate fix?

Post by eh3fifty »

sstaurus...
In other words, any fix associated with the procedure may be chosen. At least that's my interpretation, subject to the caveats mentioned by others above.
I don't believe that's what they mean.

When you quoted the AIM you left out the last part which is the most important.. it continued, "...which will permit the aircraft to commence a published instrument approach."

So you are cleared to a fix where you may commence (begin; start) the approach.... not join the approach.

A number of approaches have multiple IAFs and multiple feeders/transitions. The blurb in the AIM is stating that when you're cleared for a particular approach (without specifics of where to start the approach), you have the option of following any feeder/transition or doing direct from your current position to any IAF to commence the approach.

If you would like to deviate from that, you require clearance from ATC. It's similar to requesting a contact approach - generally (considering good airmanship) you would reference an IAP when doing a contact approach and may choose to go direct the FAF to align the airplane up with the runway. Since you are not following the approach as laid out on the plate (IAF to FAF to MAP to MAHP), ATC requires you to get a specific clearance.
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Re: Starting approach at intermediate fix?

Post by Liquid Charlie »

In the Garmin G430/530 series you can activate any leg of the approach. I have been cleared the full LNAV and then been vectored to intercept the final approach course just outside the FAWP. When this happens you simply skip down the list of waypoints on the flight plan page with the cursor, highlight the end of the leg you wish to activate and double click the direct to key.
Exactly my point -- the unit is too dumb to figure it out and you need to do a manual leg change --
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Re: Starting approach at intermediate fix?

Post by Cap'n P8 »

RAC 9.16 Has all the answers. You most certainly can proceed to any intermediate fix (IF) on the final approach course without navigating via a designated IAF. You just have to be cognizant of the required minimum IFR altitude...most likely to be MSA, as you wouldn't be allowed to leave it until you are established on a published portion of the approach.

Also, if you're planning to do a contact approach, but still want to use the FAF. make sure you're aware of your particular GPS's parameters for automatic sequencing from terminal to approach mode. Most likely within 15 degrees of track centre line at least two miles behind FAF...or somewhere thereabouts.
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Re: Starting approach at intermediate fix?

Post by sstaurus »

eh3fifty wrote:sstaurus...
In other words, any fix associated with the procedure may be chosen. At least that's my interpretation, subject to the caveats mentioned by others above.
I don't believe that's what they mean.

When you quoted the AIM you left out the last part which is the most important.. it continued, "...which will permit the aircraft to commence a published instrument approach."

So you are cleared to a fix where you may commence (begin; start) the approach.... not join the approach.

A number of approaches have multiple IAFs and multiple feeders/transitions. The blurb in the AIM is stating that when you're cleared for a particular approach (without specifics of where to start the approach), you have the option of following any feeder/transition or doing direct from your current position to any IAF to commence the approach.

If you would like to deviate from that, you require clearance from ATC. It's similar to requesting a contact approach - generally (considering good airmanship) you would reference an IAP when doing a contact approach and may choose to go direct the FAF to align the airplane up with the runway. Since you are not following the approach as laid out on the plate (IAF to FAF to MAP to MAHP), ATC requires you to get a specific clearance.
Reading RAC 9.3, I see no mention of the word 'commence'. Unless the language has been changed since my albeit slightly outdated AIM. It just mentions that you are responsible for your own obstacle clearance should you choose your own route to a fix (off of an airway, route, or transition). In any case, I believe this is one where 3 TC guys would give you 3 different answers.
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Re: Starting approach at intermediate fix?

Post by Gene Hasenfus »

I've never understood why this is such
a conundrum for people.

If you're flying into an airport with ATC,
they will give you vectors.

If you're flying into an uncontrolled airport
out in the middle of BF nowhere, ATC couldn't
care less what you do - you own the airspace
until you cancel IFR in the air, or you call them
after you land.

If you're out in the middle of BF nowhere, the
100nm altitude applies, then the 25nm MSA,
then the PT altitude. Assuming you're approaching
from the PT side, just head for the FAF and
crank it onto the final approach course, drop
the gear and down you go to the MDA.

If ATC had their way, they'd vector you inside
the FAF, every time, with at least a 110 degree
intercept angle.
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Re: Starting approach at intermediate fix?

Post by sstaurus »

^ ^ I would totally agree.
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eh3fifty
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Re: Starting approach at intermediate fix?

Post by eh3fifty »

sstaurus..

I'm getting my information from a combination of sources. The "commence" word is used in the ATC MANOPS document.. the document that ATC uses and expects pilots know what they shall and shall not do.

http://i.imgur.com/ABUVezq.png

Look at 465.1 Note 1 (B).

The AIM isn't clear and the CARs aren't explicitly clear either. However, based on what I know I see all of these to mean that you must start the approach at an IAF unless cleared otherwise.

The CARs state: "...ensure that the approach is made in accordance with the instrument approach procedure." An IAP starts at the IAF, progresses to an IF (if one exists) then to the FAF, and then to the MAP.

The ATC MANOPS concurs with this based on its definition: "INSTRUMENT APPROACH PROCEDURE — A series of predetermined manoeuvres 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."

So, if the CARs state that you must make the approach in accordance with the instrument approach procedure, and the instrument approach procedure starts at the initial approach fix (initial approach segment), then I think that's quite clear that you must start at the IAF unless otherwise cleared by ATC.

You're free to do what you want but that's my take on it and that's what I teach.

When you're in uncontrolled airspace, CAR 602.127(1) doesn't apply because there is no "appropriate air traffic control unit", and you may do whatever your little heart desires... as long as you comply with CAR 602.127(2) because that still does apply!
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Re: Starting approach at intermediate fix?

Post by B208 »

I'm getting my information from a combination of sources. The "commence" word is used in the ATC MANOPS document.. the document that ATC uses and expects pilots know what they shall and shall not do.
Eh3fifty,

The ATC MANOPS tells ATC how to do ATC stuff. It is not mandatory reading for pilots. The RAC tells pilots how to do pilot stuff. The RAC says pilots can go to the IF, then pilots can go to the IF.
The CARs state: "...ensure that the approach is made in accordance with the instrument approach procedure." An IAP starts at the IAF, progresses to an IF (if one exists) then to the FAF, and then to the MAP.
IAW does not mean that you must start at the IAF. It means that what ever part of the approach you are doing must be done IAW the plate. If you want to proceed direct an IF that is fine, as long as you are respecting the sector altitudes you are flying IAW the approach; that is, after all, why the work out sector altitudes when the TERPS an approach.
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Re: Starting approach at intermediate fix?

Post by eh3fifty »

B208..
The ATC MANOPS tells ATC how to do ATC stuff. It is not mandatory reading for pilots. The RAC tells pilots how to do pilot stuff. The RAC says pilots can go to the IF, then pilots can go to the IF.
If MANOPS tells ATC that pilots will do a certain thing then don't you think it'd be good if pilots actually did that? Let's keep our brains on here.

A slight clarification... the MANOPS and the TC AIM are both not mandatory for reading by pilots. Mandatory reading for pilots would be the CARs.

The TC AIM is recommended reading for pilots. Since it doesn't give a clear answer I have looked at additional resources. Considering that we have to work closely with ATC it made sense to check to see what ATC expects us to do when they give us an approach clearance. Makes sense right?

As far as going to the IF or not, you need specific clearance for that. Generally, what will happen is you ask ATC for clearance to fly the straight in LOC 26 approach via LONTU (IF) and they will give it to you.

Under RAC 9.16 STRAIGHT-IN APPROACHES FROM AN INTERMEDIATE FIX it says: "Subject to ATC requirements and local traffic conditions, a straight-in approach may be made from this fix." "Pilots may begin a straight-in approach from any depicted transition that intersects the final approach track inside the designated IF provided that ATC is aware of their intentions and subsequent manoeuvring is within the capabilities of the aircraft." "If the aircraft is badly positioned, laterally or vertically, after being cleared by ATC for the straight-in approach, pilots should climb to the procedure turn altitude,..."

It seems pretty clear that to do an approach from the IF requires clearance from ATC. Obviously, ATC clearances are only valid in controlled airspace.
IAW does not mean that you must start at the IAF. It means that what ever part of the approach you are doing must be done IAW the plate. If you want to proceed direct an IF that is fine, as long as you are respecting the sector altitudes you are flying IAW the approach; that is, after all, why the work out sector altitudes when the TERPS an approach.
Do you have a reference for that? As far as I know, as I have said already, is that the IAP starts at the IAF and is defined as being the lateral route from the IAF to the FAF and to the MAP... you either do a landing or follow the rest of the IAP via the missed approach procedure. You're correct that the altitude restrictions are also part of the IAP. However, the 100NM Safe Alt is not part of the IAP and neither is the sector altitude.

Based on your interpretation I could fly the procedure backwards, or go direct the FAF or OBS the MAP and intercept inside of the FAF... of course maintaining the proper altitudes like you said. Or I could fly an RNAV and go from the IAWP direct to the FAWP... it'd still go active and I could fly the approach on the GPS. You'd have to be a bit silly to think that that would be legal without clearance! You should call your local ACC and see what they think about that. Ask to speak to the supervisor.

As far as Canadian approaches being designed by TERPS... they're not. They're designed in accordance with the Canadian document, TP 308 "CRITERIA FOR THE DEVELOPMENT OF INSTRUMENT PROCEDURES".
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Re: Starting approach at intermediate fix?

Post by B208 »

eh3fifty wrote:If MANOPS tells ATC that pilots will do a certain thing then don't you think it'd be good if pilots actually did that? Let's keep our brains on here.
Dude, MANOPS doesn't say pilots must start at the IAF. If a pilot wants to go to the IF there is nothing stopping him from requesting it in controlled airspace, and nothing stopping him from just doing it in uncontrolled.
eh3fifty wrote:Do you have a reference for that?
Yep, the RAC ref previously quoted by someone else in this thread.
eh3fifty wrote:Based on your interpretation I could fly the procedure backwards,
Nope. The approach depicts headings and tracks. Flying the approach backwards would not be IAW the published approach.
eh3fifty wrote:...or go direct the FAF or OBS the MAP and intercept inside of the FAF....
In uncontrolled airspace you could, and in controlled airspace you could ask; if you felt like doing something funky. However, just because something is legal doesn't mean it is smart.
As far as Canadian approaches being designed by TERPS... they're not. They're designed in accordance with the Canadian document, TP 308 "CRITERIA FOR THE DEVELOPMENT OF INSTRUMENT PROCEDURES".
A slightly different shade of the same colour.


Just curious, are you in training to be a pilot, or a controller?
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Re: Starting approach at intermediate fix?

Post by eh3fifty »

B208..
If a pilot wants to go to the IF there is nothing stopping him from requesting it in controlled airspace
In uncontrolled airspace you could, and in controlled airspace you could ask
Those are the key points! My point was that to do anything other than going to the IAF (via direct or via a feeder route) and following the approach points in sequence, requires a specific clearance if in controlled airspace. This is clearly depicted in RAC 9.3.

The only point that isn't clear in RAC 9.3 is when it says: "...by a route present position direct to a fix associated with the selected instrument approach procedure."

That could be interpreted as any fix associated with the IAP, however, since the CARs say you must follow the IAP and any IAP starts at the IAF, it's clear to me that the fix you choose to go direct to must be one of the IAFs... unless you have clearance to do something else.

Based on your two quotes I used, it seems we are in agreement now.
A slightly different shade of the same colour.
Yes, TERPS and TP 308 are similar but different. The SOPs for Sunwing's 737 and WestJet's 737 are similar but different... a slightly different shade of the same colour. But you won't see any Sunwing pilots using the WestJet SOPs or vice versa!
Just curious, are you in training to be a pilot, or a controller?
A little jab at me, I see! No, I have an ATPL and fly for an airline. But thanks for asking. :lol:
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Re: Starting approach at intermediate fix?

Post by wingandaprayer »

Just out of curiosity, how'd you aquire a copy of MANOPS? Normally only NavCanada employees have access to those documents.
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