IAF minumum altitude

swingwing

swingwing

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Swingwing
Yesterday, at my arrival airport, they were using two ILS approaches. Both approaches have a IAF elevation of 3200' (per the plates.) The controller was clearing aircrafts down to 3000' before the IAF. Is it legal for a controller, who is providing vectors to the approach, to clear an aircraft to an altitude that is lower than the published IAF min. for that approach?
 
swingwing said:
Yesterday, at my arrival airport, they were using two ILS approaches. Both approaches have a IAF elevation of 3200' (per the plates.) The controller was clearing aircrafts down to 3000' before the IAF. Is it legal for a controller, who is providing vectors to the approach, to clear an aircraft to an altitude that is lower than the published IAF min. for that approach?
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Vectors to final? Sure. As long as it is above the minimum vectoring altitude in that sector (something you may not know).
 
swingwing said:
Yesterday, at my arrival airport, they were using two ILS approaches. Both approaches have a IAF elevation of 3200' (per the plates.) The controller was clearing aircrafts down to 3000' before the IAF. Is it legal for a controller, who is providing vectors to the approach, to clear an aircraft to an altitude that is lower than the published IAF min. for that approach?
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Yes, the controller can clear aircraft down to the MVA. I don't do it because it often causes pilots to question the altitude.
 
http://www.faa.gov/air_traffic/publications/atpubs/pcg/M.HTM

MINIMUM VECTORING ALTITUDE (MVA)- The lowest MSL altitude at which an IFR aircraft will be vectored by a radar controller, except as otherwise authorized for radar approaches, departures, and missed approaches. The altitude meets IFR obstacle clearance criteria. It may be lower than the published MEA along an airway or J-route segment. It may be utilized for radar vectoring only upon the controller's determination that an adequate radar return is being received from the aircraft being controlled. Charts depicting minimum vectoring altitudes are normally available only to the controllers and not to pilots.
 
Thank you for the info. I assumed there was some min. altitude for vectoring but when I was on the ground and thought about it, I realized I shouldn't be making those type of assumptions while in IMC.
 
If you're flying the full approach from the IAF (not getting vectors to join the approach), the controller must ensure before doing this that the altitude to which you are cleared will meet the relevent obstruction criteria all the way to the next segment on the approach.
NOTE-
1. The altitude assigned must assure IFR obstruction clearance from the point at which the approach clearance is issued until established on a segment of a published route or instrument approach procedure. ​
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The problem for the pilot is to not leave that last assigned altitude until established on a segment with a lower published altitude.
 
But, with all that said, if you ever "wonder" about an ATC instruction, ASK!

If you screw up, you might die.
If ATC screws up, you might die.
 
TMetzinger said:
No arguments.
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While controllers make plenty of mistakes (as do we pilots) I suspect that the chances of a pilot dying on any given flight due entirely to a controller's mistake are only slightly higher than the chances of that same flight being knocked down by a meteor.
 
gismo said:
While controllers make plenty of mistakes (as do we pilots) I suspect that the chances of a pilot dying on any given flight due entirely to a controller's mistake are only slightly higher than the chances of that same flight being knocked down by a meteor.
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Who's the PIC?

Not knocking ATC here at all, but anytime you have any doubt about anything while flying, you need to address it. That's your duty as captain, and my point.
 
TMetzinger said:
Who's the PIC?

Not knocking ATC here at all, but anytime you have any doubt about anything while flying, you need to address it. That's your duty as captain, and my point.
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Hey, I agree with you on that. I actually intended to reply to your earlier post with the bit about pilot's dying but somehow "slipped" a post or two down the list.:redface:
 
roncachamp said:
Yes, the controller can clear aircraft down to the MVA. I don't do it because it often causes pilots to question the altitude.
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I'm curious. Is that common in your neck of the woods? Do you know if it's generally common? In my neck of the woods, I'd be very surprised if on vectors to final on approaches to KAPA, I received altitudes that were as high as the charted IAF instead of the MVA.
 
When I've been vectored, I'm generally joining the localizer inside the IAF when I'm given a lower-than-published altitude. But that's around the DC metro area up to Philly.

I can't recall ever being given a low altitude way-the-hell-out-there.
 
TMetzinger said:
When I've been vectored, I'm generally joining the localizer inside the IAF when I'm given a lower-than-published altitude. But that's around the DC metro area up to Philly.

I can't recall ever being given a low altitude way-the-hell-out-there.
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I can. Parts of Texas - even to the LOC at KERV.

Even this weekend, I got a below-published altitude going into N66 (IIRC, I was given 4000' when the first segment of the LOC-6 was 4400). Granted it was VMC, but I had let ATC know I needed to decend below a deck to get a visual.
 
midlifeflyer said:
I'm curious. Is that common in your neck of the woods? Do you know if it's generally common? In my neck of the woods, I'd be very surprised if on vectors to final on approaches to KAPA, I received altitudes that were as high as the charted IAF instead of the MVA.
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I didn't think either the OP or Steven was talking about vectors to final. The issue, I thought, was being cleared to the IAF for the full approach at an altitude lower than the published IAF altitude, which is an extremely unusual procedure (and I've never had it happen to me) because it requires the controller to confirm that the approach is flyable (including navaid reception) below that published altitude, and I don't know how that's done (especially the navaid check part). Otherwise, while the pilot can fly to the IAF at that lower altitude, s/he must climb to the published initial segment altitude upon reaching the IAF to execute the procedure.
 
midlifeflyer said:
I'm curious. Is that common in your neck of the woods? Do you know if it's generally common?
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Well, it was common enough to cause me to stop using altitudes below what's on the IAP. It's not a big deal, only 100 or 200 feet depending on the approach.

In my neck of the woods, I'd be very surprised if on vectors to final on approaches to KAPA, I received altitudes that were as high as the charted IAF instead of the MVA.
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What altitudes are they using when vectoring to final at KAPA?
 

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Ron Levy said:
I didn't think either the OP or Steven was talking about vectors to final. The issue, I thought, was being cleared to the IAF for the full approach at an altitude lower than the published IAF altitude, which is an extremely unusual procedure (and I've never had it happen to me) because it requires the controller to confirm that the approach is flyable (including navaid reception) below that published altitude, and I don't know how that's done (especially the navaid check part). Otherwise, while the pilot can fly to the IAF at that lower altitude, s/he must climb to the published initial segment altitude upon reaching the IAF to execute the procedure.
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If the IAF is over a navaid (say, on a VOR approach), and you decend immediately after the navaid (chop and drop), then reception won't be an issue. For example, if you're cleared to a VOR approach where the VOR happens to be an IAF (NoPT), and the approach indicates that you start your descent at the VOR, I can see it happen.
 
Ron Levy said:
I didn't think either the OP or Steven was talking about vectors to final. The issue, I thought, was being cleared to the IAF for the full approach at an altitude lower than the published IAF altitude, which is an extremely unusual procedure (and I've never had it happen to me) because it requires the controller to confirm that the approach is flyable (including navaid reception) below that published altitude, and I don't know how that's done (especially the navaid check part). Otherwise, while the pilot can fly to the IAF at that lower altitude, s/he must climb to the published initial segment altitude upon reaching the IAF to execute the procedure.
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Well, I was talking about vectors to final. I think the OP was too, as he asked, "Is it legal for a controller, who is providing vectors to the approach, to clear an aircraft to an altitude that is lower than the published IAF min. for that approach?"
 
roncachamp said:
Well, I was talking about vectors to final. I think the OP was too, as he asked, "Is it legal for a controller, who is providing vectors to the approach, to clear an aircraft to an altitude that is lower than the published IAF min. for that approach?"
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On that there's no question -- it's safe, legal, and happens all the time. Perhaps I misunderstood the statement original question which said the controller "was clearing aircrafts down to 3000' before the IAF." That sounded to me like they were going to the IAF, not getting vectors to final, and that would be most inappropriate.
 
roncachamp said:
The NDB and ILS both show 8000'.
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Yes, for the FAF. Maybe we're talking semantics, but I think of the "IAF altitude" as the altitude when using the IAF as an "initial" approach fix - to begin the initial approach segment - the procedure turn, not as a "final" approach fix to descend to on the intermediate approach segment or fro where you start the descent to MDA on the final approach segment.

Unless you're saying that for the full approach, you fly to CASSE at 8000, then climb to 8700 or 9000 to do the PT, I'll stick by that.

Of course, if you view the IAF as the altitude you cross the fix on the way inbound after the PT, I agree with you based on your definition.
 
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midlifeflyer said:
Yes, for the FAF. Maybe we're talking semantics, but I think of the "IAF altitude" as the altitude when using the IAF as an "initial" approach fix - to begin the initial approach segment - the procedure turn, not as a "final" approach fix to descend to on the intermediate approach segment or fro where you start the descent to MDA on the final approach segment.

Unless you're saying that for the full approach, you fly to CASSE at 8000, then climb to 8700 or 9000 to do the PT, I'll stick by that.

Of course, if you view the IAF as the altitude you cross the fix on the way inbound after the PT, I agree with you based on your definition.
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I've said nothing about flying the full approach, we're talking about being vectored to the FAC. I've said nothing about "IAF altitude" or "FAF altitude". I wrote, "Yes, the controller can clear aircraft down to the MVA. I don't do it because it often causes pilots to question the altitude."

The MVA in the KATW area is 2600. The published minimum altitude inbound to the LOM is 2700. I can go to 2600 when vectoring to the localizer, but some pilots have questioned it. I use 2700 and everybody's happy.
 
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roncachamp said:
I've said nothing about flying the full approach, we're talking about being vectored to the FAC. I've said nothing "IAF altitude" or "FAF altitude". I wrote, "Yes, the controller can clear aircraft down to the MVA. I don't do it because it often causes pilots to question the altitude."

The MVA in the KATW area is 2600. The published minimum altitude inbound to the LOM is 2700. I can go to 2600 when vectoring to the localizer, but some pilots have questioned it. I use 2700 and everybody's happy.
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I misunderstood what you were talking about. The OP asked about the (and the thread is even titled) "IAF Minimum Altitude," so I thought your answer was directed to that subject.

Sorry I asked.
 
midlifeflyer said:
I misunderstood what you were talking about. The OP asked about the (and the thread is even titled) "IAF Minimum Altitude," so I thought your answer was directed to that subject.
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My answer was directed to his question, " Is it legal for a controller, who is providing vectors to the approach, to clear an aircraft to an altitude that is lower than the published IAF min. for that approach?"
 
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