FAF Altitude?

[poadeleted20]

Y'all look at this approach, and tell me what altitude you can descend to and when after completing the PT. And yes, I'm asking the Flight Procedures folks about it.

 

[tonycondon]

Procedure turn should be done between 2400 and 6000 feet. then down to at least 2400 feet after the procedure turn, then to at least MDA after station passage. am i missing something? seems to me to be a pretty standard way to draw the procedure turn on a non precision approach.

 

[alaskaflyer]

Well, the first obvious answer is that you may descend to the MDA...hmm...

 

[ScottM]

Looks like 2400 to me as well and is depicted like I have seen other approaches of this type. Is your concern because from the label 2400 on the procedure turn the profile view shows a line that appear to indicate that continued decent is still happening? If so I agree the drawing can cause confusion but the label is pretty clear.

 

[alaskaflyer]

I want to change my answer after I read Ron's question again

Yes Scott but I (in my limited experience) have never seen a descending line unless another minimum altitude is depicted prior to the FAF

One clue is the the different MDA's depending on whether you have DME - which explains why the 1580 notation prior to ADEBE, but you still have to maintain 2400 to the FAF...

 

[ScottM]

Yes Scott but I (in my limited experience) have never seen a descending line unless another minimum altitude is depicted prior to the FAF

That is why I am saying that the min altitude prior to the FAF is 2400. If it is supposed to be something lower then they should have printed it next to the FAF. That means either the descending line is in error or an altitude is missing from the chart. In the meantime I would descend to 2400 and no lower until I passed the FAF. Then start my descent down to either 1580 or 1220 if I could identify ADEBE.

 

[alaskaflyer]

I can't help but wonder if they were attempting to depict that with DME (or other way to identify the other fixes) the FAF is actually ADEBE (and that you can descend to 1580 after the PT then to 1220 after ADEBE)

and / but

without DME the FAF is SVM as depicted. But IMO that would be sufficiently confusing as to merit two different approach plates B)

 

[RMCN172RG]

That is why I am saying that the min altitude prior to the FAF is 2400. If it is supposed to be something lower then they should have printed it next to the FAF. That means either the descending line is in error or an altitude is missing from the chart. In the meantime I would descend to 2400 and no lower until I passed the FAF. Then start my descent down to either 1580 or 1220 if I could identify ADEBE.

That's how I interpet it also. 2400 until FAF then MDA of 1580 if you can identify ADEBE using DME then after passing ADEBE further descent to 1220 as MDA.

 

[ScottM]

I can't help but wonder if they were attempting to depict that with DME (or other way to identify the other fixes) the FAF is actually ADEBE (and that you can descend to 1580 after the PT then to 1220 after ADEBE)

and / but

without DME the FAF is SVM as depicted. But IMO that would be sufficiently confusing as to merit two different approach plates B)

The only FAF symbol is at SVM so I don't see the variable FAF approach that you are describing as being a viable option. The profile view is similar to some NDB approaches where you turn inbound to the NDB and just keep descending but those types of approaches do not have a FAF symbol.

 

[TMetzinger]

Cross the VOR outbound below 6000 and above 2400. No lower than 2400 until crossing the FAF, then no lower than 1580 unless you have ABEDE in which case you can descend to 1220 after ABEDE.

 

[alaskaflyer]

The only FAF symbol is at SVM so I don't see the variable FAF approach that you are describing as being a viable option. The profile view is similar to some NDB approaches where you turn inbound to the NDB and just keep descending but those types of approaches do not have a FAF symbol.

Yeah just trying to creatively rationalize the descending line segment post-PT and pre-FAF.

If it was depicted as a horizontal line it would be a fairly standard VOR/DME approach with stepdown fix. Which, I suppose, it is.

 

[TMetzinger]

Could be, or you could fly the PT at 4500, for instance, and be descending inbound to the FAF, perhaps so that you'd be descending at a constant stabilized rate right through the FAF...

Having a minimum instead of a fixed altitude for the PT just seems to indicate to me that they are clearing the lateral airspace within 5 NM and the vertical space between 2400 and 6000.

I'm purposely not looking at the new DVD I got today or older versions, just analyzing what Ron presented.

 

[alaskaflyer]

I can't help but wonder if they were attempting to depict that with DME (or other way to identify the other fixes) the FAF is actually ADEBE (and that you can descend to 1580 after the PT then to 1220 after ADEBE)

and / but

without DME the FAF is SVM as depicted. But IMO that would be sufficiently confusing as to merit two different approach plates B)

You know, if Ron is going to follow up on this one, I think I am going to stick to the answer above. Or else they accidentally deleted an intermediate altitude restriction as ScottD suggests.

Looking at the 5nm restriction, you are going to have to have a pretty consistent glide slope down to the MDA, not likely you will be at 2400 in the PT anyway.

 

[poadeleted20]

That is why I am saying that the min altitude prior to the FAF is 2400.

If it were, the line in the profile view from the PT to the FAF should be horizontal, not descending, and there should be a 2400 at the FAF. That's why I think Scott's right, although it is possible that it really is an unrestricted descent from completion of the PT to 1580 and then 1580 all the way to ADEBE (or the MAP if you have no DME). Gonna ask AFS-400 about this and the lack of an IAF. BTW, anyone do the math and see what descent gradient you'd need to get from 6000 MSL to the TDZE while staying within 5nm on the PT and (as required by TERPS) flying the PT level? My calculation shows it exceeds 400 ft/nm, and that's not kosher.

 

[alaskaflyer]

If it were, the line in the profile view from the PT to the FAF should be horizontal, not descending, and there should be a 2400 at the FAF. That's why I think Scott's right, although it is possible that it really is an unrestricted descent from completion of the PT to 1580 and then 1580 all the way to ADEBE (or the MAP if you have no DME). Gonna ask AFS-400 about this and the lack of an IAF. BTW, anyone do the math and see what descent gradient you'd need to get from 6000 MSL to the TDZE while staying within 5nm on the PT and (as required by TERPS) flying the PT level? My calculation shows it exceeds 400 ft/nm, and that's not kosher.

I got a little above 300 ft/min, based on a maximum 27 nm approach profile (to stay within the 5nm restriction) after passing what should be the IAF. But that is in a Cessna 170 Is there a standard speed for Terps construction?

 

[poadeleted20]

I got a little above 300 ft/min, based on a maximum 27 nm approach profile (to stay within the 5nm restriction) after passing what should be the IAF. But that is in a Cessna 170 Is there a standard speed for Terps construction?

Unless you include descending in the PT (which TERPS prohibits SIAP developers from considering), I don't think you can come up with 27nm in which to descend from over SVM to the touchdown zone while staying within 5nm. The most I get is about 12nm from SVM to the start of the PT, then from the end of the PT to the runway.

 

[alaskaflyer]

Unless you include descending in the PT (which TERPS prohibits SIAP developers from considering), I don't think you can come up with 27nm in which to descend from over SVM to the touchdown zone while staying within 5nm. The most I get is about 12nm from SVM to the start of the PT, then from the end of the PT to the runway.

Doh! I was including the 10 nm roundtrip from the VOR back to the FAF/VOR. Throw out the drogue chute! Though it may very well be that you are well below 6000 when starting the approach.

 

[RMCN172RG]

OK I pulled out an old copy from July last year IAF is MULINS DME 5 on the 306 radial from SVM at 2400 no PT. Then fly 126 to SVM FAF 2400. Then fly 124 to ADEBE and identical to the one above from there.

 

[Brad Z]

My guess is that they are missing an altitude (and DME) label at the FAF.

Did you add the 2100 yourself?

 

[alaskaflyer]

I'm beginning to think this is another April Fools joke - too bad it's published!

 

[TangoWhiskey]

Cross the VOR outbound below 6000 and above 2400. No lower than 2400 until crossing the FAF, then no lower than 1580 unless you have ABEDE in which case you can descend to 1220 after ABEDE.

I concur with this one, as others have also stated it. I think it's the "slanted line" inbound that makes the confusion. That could mess up a a visual thinker, but the symbology clears it up, absent a new intermediate DA depicted at the VOR (FAF), you can't go lower than was previously charted (2400).

EDIT: Ok, read down far enough to see Scott's post. Anybody have the Jepp version of this plate?

 

[TangoWhiskey]

Here's a screenshot from the G1000... the Jepp DB has 2400 as the altitude til past the FAF, then 1800 on the missed. (they don't show chart the MDA on the glass--you can dial it in, though, for alerting).

Would like to see the Jepp version from Dr. Bruce's JeppView.

 

[TMetzinger]

On the next cycle of NACO plates (effective 10 April)... it's shown as the same. So if it's an error, it hasn't been caught and corrected yet.

 

[gibbons]

I don't think anybody on the board has a CFII any wetter than mine, but I'll play.....

Cross the VOR outbound below 6000 and above 2400. No lower than 2400 until crossing the FAF, then no lower than 1580 unless you have ABEDE in which case you can descend to 1220 after ABEDE.

This is my answer also.

Yeah just trying to creatively rationalize the descending line segment post-PT and pre-FAF.

If it was depicted as a horizontal line it would be a fairly standard VOR/DME approach with stepdown fix. Which, I suppose, it is.

Another reason to use Jepp charts (see below)

My guess is that they are missing an altitude (and DME) label at the FAF.

Why? There is no DME because the FAF is the VORTAC. Here's another one almost just like it except for the "at or below" crossing the VORTAC outbound and there's no altitude on it either.
http://204.108.4.16/d-tpp/0803/06126VA.PDF

If it were, the line in the profile view from the PT to the FAF should be horizontal, not descending, and there should be a 2400 at the FAF.

I wouldn't expect a 2400 at the FAF however, since it's the same altitude as the inbound leg of the procedure turn.

 

[ghogue]

Ron,
I agree with Scott that a missing altitude is missing from the FAF. It may or may not be lower than 2400, but (without going to TERPS) I am pretty sure that any depicted FAF requires an altitude to be associated with it. If the FAF is 2400, then the sloping line from the PT to the FAF is incorrect and should, as you stated, be horizontal.

gary

 

[maddog52]

My 2 cents. 2400 till completion of procedure turn then down to 1580 to ADEBE. Then 1220 if you have ADEBE. The cross is there simply to denote the FAF for the timing for non DME aircraft. I don't beleive TERPS actually requires a hard altitude at the FAF unless it's needed. On my way to look this up.

 

[gibbons]

After re-reading Tim's post I want to change my answer and disagree:

Cross the VOR outbound below 6000 and above 2400. No lower than 2400 until crossing the FAF, then no lower than 1580 unless you have ABEDE in which case you can descend to 1220 after ABEDE.

It should be no lower then 2,400 outbound on the PT, no lower than 2,100 once established inbound on the PT and maintain 2,100 until crossing the FAF, (the rest unchanged).

I am pretty sure that any depicted FAF requires an altitude to be associated with it.

I think you might be referring to the altitude assigned to the inbound leg of the procedure turn. On NOS charts it is often printed near the FAF, but it's not associated with the fix itself - it's the min altitude once established inbound to the fix.

Here are two profiles for the VOR / TACAN RWY 26 into Tulsa. The top is the jepp chart, the bottom is the government issue. My point is that the 2000 shown to the right of the FAF on the government chart isn't related to the FAF, but to the inbound leg to the FAF. Same as on the original chart posted by Ron. I think it's much easier to see in the Jepp chart.

I don't think there's much confusion about the original approach.

 

[bbchien]

Another reason to spring for JEPP. Sigh.

 

[AWACSEng]

Well, what does the Jepp approach show?

 

[Areeda]

The current NACO and Jepp profile views look like:

Seems pretty clear to me that we should cross the Salem VOR at 2400 feet. Since this is a Cat A only we have 10 miles to descend from 6,000 to 2400 which is 360 ft/nm or 540 ft/min at 90 kts.

Joe

 

[ghogue]

I think you might be referring to the altitude assigned to the inbound leg of the procedure turn. On NOS charts it is often printed near the FAF, but it's not associated with the fix itself - it's the min altitude once established inbound to the fix.

Here are two profiles for the VOR / TACAN RWY 26 into Tulsa. The top is the jepp chart, the bottom is the government issue. My point is that the 2000 shown to the right of the FAF on the government chart isn't related to the FAF, but to the inbound leg to the FAF. Same as on the original chart posted by Ron. I think it's much easier to see in the Jepp chart.

I don't think there's much confusion about the original approach.

No, I am referring to the FAF altitude. The altitude adjacent to the FAF symbol is the FAF altitude and it is associated to the FAF. You are correct in that it is the altitude you descend to after the PT, and prior to the FAF, however in TERPS this is referred to as the FAF altitude, i.e., the altitude you do not descend below until after crossing the FAF.

 

[gibbons]

Did you add the 2100 yourself?

OK, wait. Where did the 2100 come from? Looking at the original chart (which did not have the 2100) and not this profile (which did) I'll go back to my original statement... 2,400 outbound, 2,400 inbound 'til crossing FAF.

 

[jesse]

test...

 

[Don Jones]

Well my II is almost as wet as Chips, but seems to me the only reason as stated earlier for the FAF symbol is for timing for the missed, and after completion of the procedure turn at or above 2400, once established inbound on the radial you can desend down to 1580 ft. Here is another one from around here, it differs in the missed is the VOR which is located on the field and hence no FAF is depicted. It is interesting how Jepp and Naco depict it differently, where does Jepp get the info? Did they just depict it the way they thought it should be?

 

[gibbons]

Well my II is almost as wet as Chips, but seems to me the only reason as stated earlier for the FAF symbol is for timing for the missed, and after completion of the procedure turn at or above 2400, once established inbound on the radial you can desend down to 1580 ft.

I don't agree. 2,400 throughout the entire procedure turn, then 1,580 after crossing the FAF.

 

[Dave Siciliano]

I agree that as published, 2400 to the FAF, then down to 1580 and another step down to 1220 if one can identify ADEBE. The descending line from 2400 to the VORTAC is incorrect; it should be level (as the Jepp chart shows).

Without going to the Jepp chart, one wouldn't know if the line showing the descent from 2400 to the FAF was incorrect, or if there should have been a step-down altitude at the FAF. To be safe, one would have to respect the 2400 to the FAF on the FAA chart.

Best,

Dave

 

[Dave Siciliano]

Bill Butler on AvSig made these comments:


2400 until completion of the PT, which may or may not be at the VORTAC, then descend to 1580. If you can identify ADEBE (DME required) you can then descend to 1220.

(Procedure not authorized for CAT B,C,D)

The 5 mile restriction assures that the 1749' obstruction remains in the secondary area and once you are re-established on the 304 radial, there is no need to protect it. ADEBE seems to exist to assure the passage of the 1164' obstrution to the right of the 124 radial<?>

This looks like a procedure developed for one influential Bonanza owner <g>


Best,

Dave

 

[Don Jones]

I don't agree. 2,400 throughout the entire procedure turn, then 1,580 after crossing the FAF.

Well I know I would fly it keeping 2400 to the FAF, regardless of the way it's charted. It sure doesn't make sense the way it's shown.

 

[Dave Siciliano]

Some others have flipped through some similar charts and the line to the FAF is level; thay also had an at or above altitude at the FAF.

Best,

Dave

 

[Areeda]

Does anyone know where to get the text description of instrument approaches that are used to create the NACO and Jepp plates?

Joe