IFR Approach Debate

[David Megginson]

"

But I can't imagine @David Megginson' is correct that in Canada, a clearance direct to an IAF or IF combined with an approach clearance, cancels the "direct" portion and allows a pilot to create their own intercept to the FAC without ever going to the IAF or IF.

But that's not what I wrote. I wrote that when they just clear you "for the approach" without any other instructions, you can fly the approach any way you want. If they simply clear you direct to the IF, IWP, or IAWP, that's not an approach clearance. If they clear you for the approach via the IF, then that's part of the approach clearance.

Usually, of course, they give you a limit when the clearance will become effective, eg "Fly heading 350. On intercept, cleared for the ILS 32 approach..." or "After BONDE, cleared for the RNAV 35 approach..."

If they just say "cleared for the approach," then you're cleared, even if you're 35 miles back — that replaces any older clearances — and you can navigate as needed. If it were an NDB approach, for example, I'd turn towards the navaid and start descending to MSA as soon as applicable; if it were an RNAV approach, I'd turn towards the most suitable IAWP or IWP.

I always reply telling them what I'm planning to do, even though it's not required. for example, if they said "XXX is cleared for the RNAV 35 approach into Pembroke" I'd reply "XXX cleared for the RNAV 35 approach into Pembroke. Turning direct BONDE, starting descent to 3,000." That gives them a chance to catch it if there was a mistake.

 

[David Megginson]

Really? Where does you are cleared for the approach you can descend to the MDA come from. Sounds like a good way to die.

• 602.127 (1) 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.

Thanks for catching my typo — MSA, not MDA.

 

[PaulS]

You mean like

Yes, if I recall the Dot 65 correctly, ATC should have repeated the altitude with the approach clearance as, "maintain 3000 until AGNSS. Cleared for..." But the OP's description indicates the problem was not the altitude. It was not understanding the lateral instruction to go direct to AGNSS and turn onto the extended FAC 6.7 nm before the PFAF.

Unless the controller didn't care about the altitude. The op was at the correct altitude for AGNSS already, but even if he wasn't, if the controller had no reason to restrict altitude, he wouldn't have. This would have freed the op to descend to 3000 for AGNSS.

 

[PaulS]

I think the AIM 5-4-6 Para 6 covers this.

 

[aterpster]

I don't understand the comments saying the controller was wrong. Exactly what is wrong with a 90 degree turn at an IF? It's the most common turn at an IF on a TAA. You are 2.4 from the next waypoint and almost 7 from the FAF. I'd be flying direct to AGNSS per the instruction and turning onto the FAC.

The controller was wrong. They were not on a published route or segment. The correct clearance would be, "Cross AGNSS at 3,000, cleared ILS 22R."

 

[aterpster]

99.9999% certain he did not mean while 35 miles away from any IAF, but that "cleared for the approach" means permission to descent to all published altitudes, in sequence, including the MDA.

Yes, provided you are on a published route or segment. This is shades of TWA 514.

 

[Clip4]

Thanks for catching my typo — MSA, not MDA.

I wish I would have realized it was a typo.

 

[midlifeflyer]

The controller was wrong. They were not on a published route or segment. The correct clearance would be, "Cross AGNSS at 3,000, cleared ILS 22R."

As you can see for my other posts, I agree that should have been said - in those exact words. But the real point is that this arguably missing part of the clearance has zero to do with the scenario since altitude wasn't the problem. It was the failure to follow the lateral instruction to fly to the AIF/IF.

 

[midlifeflyer]

Yes, provided you are on a published route or segment. This is shades of TWA 514.

to all published altitudes, in sequence,

Example of a violent agreement

 

[aterpster]

As you can see for my other posts, I agree that should have been said - in those exact words. But the real point is that this arguably missing part of the clearance has zero to do with the scenario since altitude wasn't the problem. It was the failure to follow the lateral instruction to fly to the AIF/IF.

The issuance of the proper clearance would have (should have?) precluded the lateral ambiguity in the pilot's mind.

 

[midlifeflyer]

I think the AIM 5-4-6 Para 6 covers this.

Yes and no.

Yes, it absolutely tells us what we are supposed to do in that scenario. As a number of us have said, maintain the last assigned altitude, fly to the fix and start the approach. It's covered in Chapter 3 of the IPH as well.

The "no" is the red herring of the controller not restating the assigned altitude, as covered in 4-8-1 of the ATC manual. Funny, the lack of a new/repeated altitude assignment is a scenario I give during IPCs But in my version it's cleared direct to the IF through a TAA with no altitude assignment other than the last assigned altitude. I only did it to test knowledge that the TAA altitudes are "published segments" of the approach. But even there, ATC is supposed to tell us to maintain an altitude "until entering the TAA."

 

[midlifeflyer]

The issuance of the proper clearance would have (should have?) precluded the lateral ambiguity in the pilot's mind.

I don't see how. Instructed to proceed direct AGNSS. Last assigned altitude 3,000, published altitude AGNSS 3,000. "Gee, I'm, not sure about what altitude I should use. I know! I'll stay at 3,000 but turn 60 degrees! That should be right."

The again, given how clear the AIM and IPH are about the pilot's obligations, I don't see the ambiguity to begin with. My bad, I guess.

 

[aterpster]

The again, given how clear the AIM and IPH are about the pilot's obligations, I don't see the ambiguity to begin with. My bad, I guess.

I don't either. But, in fact, it did exist in his mind. The proper clearance may have caused him to cross AGNSS.

 

[PaulS]

I don't either. But, in fact, it did exist in his mind. The proper clearance may have caused him to cross AGNSS.

He was cleared to AGNSS, that is the beginning of the approach, unless instructed otherwise, that is where he should have flown to.

The altitude thing, I'm still unsure about that. But Mark should know what he is talking about.

 

[luvflyin]

Unless the controller didn't care about the altitude. The op was at the correct altitude for AGNSS already, but even if he wasn't, if the controller had no reason to restrict altitude, he wouldn't have. This would have freed the op to descend to 3000 for AGNSS.

"

But that's not what I wrote. I wrote that when they just clear you "for the approach" without any other instructions, you can fly the approach any way you want. If they simply clear you direct to the IF, IWP, or IAWP, that's not an approach clearance. If they clear you for the approach via the IF, then that's part of the approach clearance.

Usually, of course, they give you a limit when the clearance will become effective, eg "Fly heading 350. On intercept, cleared for the ILS 32 approach..." or "After BONDE, cleared for the RNAV 35 approach..."

If they just say "cleared for the approach," then you're cleared, even if you're 35 miles back — that replaces any older clearances — and you can navigate as needed. If it were an NDB approach, for example, I'd turn towards the navaid and start descending to MSA as soon as applicable; if it were an RNAV approach, I'd turn towards the most suitable IAWP or IWP.

I always reply telling them what I'm planning to do, even though it's not required. for example, if they said "XXX is cleared for the RNAV 35 approach into Pembroke" I'd reply "XXX cleared for the RNAV 35 approach into Pembroke. Turning direct BONDE, starting descent to 3,000." That gives them a chance to catch it if there was a mistake.

There was thread, I thought it was here but can’t find it so it must have been on another forum, where it was a US airport near the border and Canada ran ATC to it. The US had delegated the airspace to Canada. A pilot got a ‘Cleared for the Approach’ while not on a published route/segment. And we learned that yes, absent specific routing contained in the Clearance, it’s a ‘roll your own’ thang to get established on the Approach.

 

[wayneda40]

I don't understand the comments saying the controller was wrong. Exactly what is wrong with a 90 degree turn at an IF? It's the most common turn at an IF on a TAA. You are 2.4 from the next waypoint and almost 7 from the FAF. I'd be flying direct to AGNSS per the instruction and turning onto the FAC.

I agree with Mark. Furthermore, assuming you're flying magenta needles (as you should be) on the initial approach segments, the GPS/Autopilot will do a perfect turn anticipation just prior to AGNNS (a fly-by). IMHO, I see no logic in making up your own intercept vectors.

 

[jordane93]

When in doubt, just ask. I probably would have captured the LOC in LNAV and then armed the approach once I was on lined up on the final approach course.

 

[aterpster]

He was cleared to AGNSS, that is the beginning of the approach, unless instructed otherwise, that is where he should have flown to.

The altitude thing, I'm still unsure about that. But Mark should know what he is talking about.

In the original post:

"On the en-route structure we were cleared direct AGNSS and told to descend to 3000'. The GPS showed that we were 35 miles from this fix."

The controller was required to assign not less than MVA. If in doubt, clarify!

 

[PaulS]

In the original post:

"On the en-route structure we were cleared direct AGNSS and told to descend to 3000'. The GPS showed that we were 35 miles from this fix."

The controller was required to assign not less than MVA. If in doubt, clarify!

No, what I mean is if he was not assigned 3,000 35 miles out, but was at 5,000. Could he have descended to 3,000 when he was "Cleared for the approach" without an altitude assignment.

 

[dmspilot]

No, what I mean is if he was not assigned 3,000 35 miles out, but was at 5,000. Could he have descended to 3,000 when he was "Cleared for the approach" without an altitude assignment.

No, you aren't on the approach yet, you can't just make up your own altitudes.

 

[midlifeflyer]

He was cleared to AGNSS, that is the beginning of the approach, unless instructed otherwise, that is where he should have flown to.

The altitude thing, I'm still unsure about that. But Mark should know what he is talking about.

It's in the same AIM paragraph you mentioned:

e. The following applies to aircraft on radar vectors and/or cleared "direct to" in conjunction with an approach clearance:

1. Maintain the last altitude assigned by ATC until the aircraft is established on a published segment of a transition route, or approach procedure segment, or other published route, for which a lower altitude is published on the chart. If already on an established route, or approach or arrival segment, you may descend to whatever minimum altitude is listed for that route or segment.​

No, what I mean is if he was not assigned 3,000 35 miles out, but was at 5,000. Could he have descended to 3,000 when he was "Cleared for the approach" without an altitude assignment.

No. Not until on a published segment with a lower altitude. If assigned 5,000, the pilot would have to maintain that until AGNSS.

Compare the chart we have been discussing to this one (also an ILS OR LOC). With a last-assigned 5,000' altitude and given, "direct KAKLE, cleared for the approach" without a new altitude assignment, the pilot could descend to 4,000 once within 30 NM of KAKLE, the TAA being considered a "published segment."

 

[PaulS]

It's in the same AIM paragraph you mentioned:

e. The following applies to aircraft on radar vectors and/or cleared "direct to" in conjunction with an approach clearance:

1. Maintain the last altitude assigned by ATC until the aircraft is established on a published segment of a transition route, or approach procedure segment, or other published route, for which a lower altitude is published on the chart. If already on an established route, or approach or arrival segment, you may descend to whatever minimum altitude is listed for that route or segment.​

No. Not until on a published segment with a lower altitude. If assigned 5,000, the pilot would have to maintain that until AGNSS.

Compare the chart we have been discussing to this one (also an ILS OR LOC). With a last-assigned 5,000' altitude and given, "direct KAKLE, cleared for the approach" without a new altitude assignment, the pilot could descend to 4,000 once within 30 NM of KAKLE, the TAA being considered a "published segment."
View attachment 100358

Thanks Mark, makes sense.

 

[aterpster]

No, what I mean is if he was not assigned 3,000 35 miles out, but was at 5,000. Could he have descended to 3,000 when he was "Cleared for the approach" without an altitude assignment.

No. And, the approach clearance wouldn't be complete without "Cross AGNSS at (or at or above) 3,000."

 

[John Collins]

I agree with Mark's analysis. If the controller did not include the altitude as part of the clearance, yes that is not correct, but regardless, the pilot is expected to maintain the last assigned altitude until on a published segment of the procedure. In this case, the random RNAV route direct to the IF was the last assigned route and the aircraft is not on a published segment until the completes the turn at the IF and is established on the localizer. A direct to a fix is not a vector, it uses RNAV navigation to the fix. Unless the fix is a fly over fix, turn anticipation is expected at the IF. Flying a heading is a vector and one should not turn to a heading to intercept the localizer as the OP stated.

 

[MauleSkinner]

Unless the fix is a fly over fix, turn anticipation is expected at the IF.

Just to go completely off topic, basically any fix at which you’re making a turn on a ground-based procedure is technically a fly-by, right?

obviously on an RNAV procedure it will use flyover or fly-by icons.

 

[aterpster]

I agree with Mark's analysis. If the controller did not include the altitude as part of the clearance, yes that is not correct, but regardless, the pilot is expected to maintain the last assigned altitude until on a published segment of the procedure. In this case, the random RNAV route direct to the IF was the last assigned route and the aircraft is not on a published segment until the completes the turn at the IF and is established on the localizer. A direct to a fix is not a vector, it uses RNAV navigation to the fix. Unless the fix is a fly over fix, turn anticipation is expected at the IF. Flying a heading is a vector and one should not turn to a heading to intercept the localizer as the OP stated.

ATC, "Cross AGNSS at 3,000. Cleared ILS 22R."

When do you heave 5,000?

 

[coma24]

One thing that isn't often covered (or issued as a clearance) is what happens if you're cleared for an approach without an altitude to maintain while on an airway. Pilots often quote the "unless established on a segment of the approach," without the portion referring to a 'published route.' That would include STARs and airways. So, if the airway you're on now leads to an IAF or feeder, they can issue the clnc while on the airway and without an altitude. All that said, I'm yet to see this happen in the wild. Anytime we've issued it in the simulated environment (V23 heading to OCN VOR), pilots invariably ask for an altitude to maintain since they're not yet established on a segment of the approach.

 

[dtuuri]

I agree with Mark's analysis.

Mark's analysis is based on the OP turning 60° to join final. The OP turned only 30°. Just sayin'.

Unless the fix is a fly over fix, turn anticipation is expected at the IF.

Yes, as stated in the AIM with my bolding:

5-3-5 Airway or Route Course Changes

a. Pilots of aircraft are required to adhere to airways or routes being flown. Special attention must be given to this requirement during course changes. Each course change consists of variables that make the technique applicable in each case a matter only the pilot can resolve. Some variables which must be considered are turn radius, wind effect, airspeed, degree of turn, and cockpit instrumentation. An early turn, as illustrated below, is one method of adhering to airways or routes. The use of any available cockpit instrumentation, such as Distance Measuring Equipment, may be used by the pilot to lead the turn when making course changes. This is consistent with the intent of 14 CFR Section 91.181, which requires pilots to operate along the centerline of an airway and along the direct course between navigational aids or fixes.

b. Turns which begin at or after fix passage may exceed airway or route boundaries. FIG 5-3-1 contains an example flight track depicting this, together with an example of an early turn.​

The OP may well have been doing 3 miles/minute (or more) and been within one minute of the AGNSS route change. He used up about 10 seconds in the 30° turn with 20 more seconds to go. I'm thinking he's flying a jet, you guys see him in a 172.

 

[coma24]

Regarding the original question, the 90 deg intercept at the IF was legal. 7110.65 4-8-2 (h)(2): "Established on a heading or course direct to the IF at an angle not greater than 90 degrees..."

It would've been incorrect for the controller to issue "xx miles from AGNSS, fly hdg 090, cross AGNSS at 3000..." as this wasn't a vector to the final approach course. Since the aircraft was already established direct AGNSS, the only thing that needed to be said was, "cross AGNSS at 3000, cleared ILS RWY 22 approach," as has been eluded to in previous posts. It was a controller error not to include the establish to maintain until that point. Thankfully, the current altitude matched the crossing alt, so this is more of a technical error than one which posed a real risk.

 

[midlifeflyer]

Just to go completely off topic, basically any fix at which you’re making a turn on a ground-based procedure is technically a fly-by, right?

I think ground based navaids are actually "fly-over." Think about what you do when you fly VOR approaches. You wait until the needle flips - course reversal - before turning. Of course, as a practical matter, we often fly-by them especially enroute.

You are probably familiar with the maximum turn (the reason for the "NA when approaching from" certain directions on approach plates). The max turn for a ground-based NAVAID is 120°. RNAV it's only 90°. The reason is historical but it comes down the historical fact that turn anticipation was not assumed. Basically, the amount of turn anticipation (how early you turn) increases as the angle increases. At certain speeds, the difference is great enough that can place you outside of the area protected for the turn, so they limit the "fly-by" RNAV turn to 90 while the old school "fly-over" can be 120.

I've also seen discussion where a faster aircraft using RNAV anticipates a turn in an instruction like "direct XYZ VOR, then outbound on the 260 degree radial." with ATC getting very upset about the turn which never got closer than 10 miles to the VOR.

 

[aterpster]

Just to go completely off topic, basically any fix at which you’re making a turn on a ground-based procedure is technically a fly-by, right?

obviously on an RNAV procedure it will use flyover or fly-by icons.

I can only speak to the G-5000. It will permit me to change a FB in the active flight plan to a FO and toggle it back to FB.

 

[PaulS]

Mark's analysis is based on the OP turning 60° to join final. The OP turned only 30°. Just sayin'.


Yes, as stated in the AIM with my bolding:

5-3-5 Airway or Route Course Changes

a. Pilots of aircraft are required to adhere to airways or routes being flown. Special attention must be given to this requirement during course changes. Each course change consists of variables that make the technique applicable in each case a matter only the pilot can resolve. Some variables which must be considered are turn radius, wind effect, airspeed, degree of turn, and cockpit instrumentation. An early turn, as illustrated below, is one method of adhering to airways or routes. The use of any available cockpit instrumentation, such as Distance Measuring Equipment, may be used by the pilot to lead the turn when making course changes. This is consistent with the intent of 14 CFR Section 91.181, which requires pilots to operate along the centerline of an airway and along the direct course between navigational aids or fixes.

b. Turns which begin at or after fix passage may exceed airway or route boundaries. FIG 5-3-1 contains an example flight track depicting this, together with an example of an early turn.​

The OP may well have been doing 3 miles/minute (or more) and been within one minute of the AGNSS route change. He used up about 10 seconds in the 30° turn with 20 more seconds to go. I'm thinking he's flying a jet, you guys see him in a 172.

I don't think the OP has posted in the thread again, but I do suspect he was in a jet or a fast turbo prop. He also may have been anticipating the turn and his co pilot was saying it was a flyover waypoint. It would be nice to know what he was flying and what the RNAV capabilities were. So many questions.

 

[MauleSkinner]

I think ground based navaids are actually "fly-over." Think about what you do when you fly VOR approaches. You wait until the needle flips - course reversal - before turning. Of course, as a practical matter, we often fly-by them especially enroute.

You are probably familiar with the maximum turn (the reason for the "NA when approaching from" certain directions on approach plates). The max turn for a ground-based NAVAID is 120°. RNAV it's only 90°. The reason is historical but it comes down the historical fact that turn anticipation was not assumed. Basically, the amount of turn anticipation (how early you turn) increases as the angle increases. At certain speeds, the difference is great enough that can place you outside of the area protected for the turn, so they limit the "fly-by" RNAV turn to 90 while the old school "fly-over" can be 120.

I've also seen discussion where a faster aircraft using RNAV anticipates a turn in an instruction like "direct XYZ VOR, then outbound on the 260 degree radial." with ATC getting very upset about the turn which never got closer than 10 miles to the VOR.

But they also allow for leading the turn if you have the equipment (such as DME) to identify n you’re getting close…that verbiage has always been in the AIM, but I can’t remember whether it only applies to enroute or not.
I probably should look that up when I’m not supposed to be not doing what I’m doing now

 

[PaulS]

There is a go jet with the flight number UA4833, goes to EWR, it's a CRJ-550, if that was it, at 5 miles the turn probably didn't matter.

 

[midlifeflyer]

ATC, "Cross AGNSS at 3,000. Cleared ILS 22R."

When do you heave 5,000?

Whenever I want to so so long as I am at 3,000 when I reach AGNSS (you did say "at" not "at or above").

I can easily see a controller forgetting to repeat the same altitude he gave the pilot moments earlier. I have a harder time seeing a controller forgetting to assign a new altitude, although it can obviously happen. I also see a difference from the pilot side. I would not question the former and absolutely would question the later since I have no desire to dive as son as I reach AGNSS.

 

[midlifeflyer]

There is a go jet with the flight number UA4833, goes to EWR, it's a CRJ-550, if that was it, at 5 miles the turn probably didn't matter.

The description didn't sound like guesstimating turn anticipation. He presented it as creating an intercept heading. But if you are right it probably doesn't matter. If you think you know which one it is, go to Flightawaare and se if you can pull up the track.

 

[PaulS]

The description didn't sound like guesstimating turn anticipation. He presented it as creating an intercept heading. But if you are right it probably doesn't matter. If you think you know which one it is, go to Flightawaare and se if you can pull up the track.

I know re the OP and turn anticipation, but just trying to figure it out. I feel like I'm doxing the guy, I don't want to do that, but I did look at the flight paths for the last seven days and none fit the profile he presents IMO.

 

[bluesky74656]

Regarding the original question, the 90 deg intercept at the IF was legal. 7110.65 4-8-2 (h)(2): "Established on a heading or course direct to the IF at an angle not greater than 90 degrees..."

It would've been incorrect for the controller to issue "xx miles from AGNSS, fly hdg 090, cross AGNSS at 3000..." as this wasn't a vector to the final approach course. Since the aircraft was already established direct AGNSS, the only thing that needed to be said was, "cross AGNSS at 3000, cleared ILS RWY 22 approach," as has been eluded to in previous posts. It was a controller error not to include the establish to maintain until that point. Thankfully, the current altitude matched the crossing alt, so this is more of a technical error than one which posed a real risk.

AGNSS isn’t an IAF. There is no IAF for this approach. You can’t get on this approach apart from vectors to final. It was a mistake for the controller not to issue the vector.

 

[David Megginson]

My takeaway from this thread is that while "cleared for the approach" by itself is perfectly standard (and well-understood) in Canada, if I ever hear it when I'm flying in the U.S. again after the pandemic, I'll query the controller and ask for clarification.

 

[John Collins]

ATC, "Cross AGNSS at 3,000. Cleared ILS 22R."

When do you heave 5,000?

The OP wrote: [quite]On the en-route structure we were cleared direct AGNSS and told to descend to 3000'. The GPS showed that we were 35 miles from this fix.[/quote]

So I would heave 5000 and descend to 3000 at that point.