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-   -   Approach chart minimun altitud interpretation (https://www.pprune.org/tech-log/412128-approach-chart-minimun-altitud-interpretation.html)

tinerrr 14th Apr 2010 23:47

Approach chart minimun altitud interpretation
 
Hi there,

I have doubts about how to interpretate this chart properly.
The question in simple. If we are cleared for the aproach and shoot it from TUM VOR. We will proceed outbound R- 186 and the question is: Should we maintain 2200`until stablished on the localizer? or, May we descend to 1700' even during the procedure turn and not stablized on the localizer yet?

I didnīt find the jeppesen chart on internet to be able to post it here. Thereīs a note on the current jeppesen chart on the 2200' altitude that says "recommended". I understand than if the altitud is recommended is not a mandatory minimum altitude, am I wrong?

Would this note change your answers?

Thank you very much for you help.

http://www.costaricaaviation.com/cha...ILS_RWY_3R.PDF

galaxy flyer 14th Apr 2010 23:50

It would help greatly to give us the ICAO identifier. I have JeppView charts on my laptop.

GF

p51guy 15th Apr 2010 00:52

Descent below the initial altitude assigned would require a transition altitude on an approach chart or you would be required to maintain your last assigned altitude when cleared for the approach. Does anybody remember the round hill mountain crash going into Dulles 35 years ago when they descended to initial approach altitude? TWA hit round hill descending to OM crossing altitude too soon. Cleared for the approach to me means you can descend to any altitude shown on your approach plate. If you are not on an approach route you have no min altitude so stay where you were.

Ndicho Moja 15th Apr 2010 02:10

From what I see here, and the chart is difficult to read from the reproduction;

1. Maintain 3300ft in the hold or over AT. VOR can be used if AT is unusable.
2. Once established out bound on the 186 bearing AT you may descend to not lower than 2200ft until established inbound on the I-NAT LOC 3R.
3. Once established on the LOC you can descend to the minima with a requirement to cross LAMB (? illegible ) at or above 1700ft.

So, Yes is the answer to your question.

abc1 15th Apr 2010 02:27

Couldn't you descend to 1700'? The procedure turn has you completing the turn inside INAT11.So when you roll out you shouldn't be bellow 1700'.
The 2200 is the next step in the step down from 3100 step at the TBG VOR or have I got it wrong again?

hawk37 15th Apr 2010 12:44

How can I view this chart? In the original post, at the very bottom, there's a small box with a red X in it. I try right click and left click but this doesn't produce an image. How do you guys see it? Hawk

bfisk 15th Apr 2010 14:50

The chart isn't working here either. So impossible to help you without any clue to what chart you are referring ;)

Mansfield 15th Apr 2010 16:10

It is the MPTO (Tocumen, Panama) ILS 3R.

I believe that ABC1 has it correct...the 2200 foot minimum applies to the TBG 8 DME fix. If you were turning inbound to intercept the localizer inside of the TBG 8 fix, you could descend with respect to the 1700 foot minimum at LAMBI. If, for some reason, you were outside of the TBG 8 fix, the 2200 foot restriction would apply until crossing the fix inbound.

That said, I don't see any reference to your comment about the word "Recommended" on the chart here...I'd be interested to know what that looks like.

seilfly 15th Apr 2010 17:25

This is a USAF-created procedure. I am looking in the legend of the DOD FLIP now, and for teardrop turns they are also giving a turn altitude. Looking at the legend, the turn altitude is 2200 minimum. The AFMAN 11-217V1, the USAF's Instrument Flight Bible, states that this altitude is minimum until established on the inbound segment. (Ref Dod FLIP Legend and the AFMAN 11-217V1 (chapter 13.9.4.2)).

But since that extra initial approach segment is there, it seems more cluttered; I would definitely treat the 2200 as a minimum for the teardrop procedure until established inbound, and if I was flying from the IAF "TBG" I would treat the altitude as minimum until established AND at TBG 8 DME.

The above post is probably the most conservative and safest way to read this procedure... My 2 cents...

tinerrr 15th Apr 2010 23:35

I found the jeppesen charts from another site. Letīs try with this link:

http://vatca.net/files/mpto.pdf

Scroll down and you will find the chart 11-1. Is the Ils 03R at tocumen int. airport (MPTO/PTY).

You can see the "recommended" note for the 2200 altitude. Does that make you mind change?

Thanks to everyone for your opinions.

abc1 16th Apr 2010 03:02

Sorry guys this got me thinking as the last time we have done something like this is many moons ago and therefore I am trying to get to the right answer.

Looking at Jepp introduction section page 109, 1700' seems to be the applicable altitude, as the profile view legend describes the depicted turn as a descending turn to minimum altitude. Note 2 is a recommended altitude applicable on the profile from TBG VOR to INAT11.
Since the turn falls inside INAT11 I am inclined to think that 1700' is the applicable altitude.
Any further thoughts on this?

aterpster 18th Apr 2010 00:52

Seilfly

But since that extra initial approach segment is there, it seems more cluttered; I would definitely treat the 2200 as a minimum for the teardrop procedure until established inbound, and if I was flying from the IAF "TBG" I would treat the altitude as minimum until established AND at TBG 8 DME.

The above post is probably the most conservative and safest way to read this procedure... My 2 cents...
I can't download the chart.

Nonetheless, you are stating "the least cost of being wrong" principle. That principle tends to save lives, especially in third world instrument procedures.

aterpster 18th Apr 2010 13:36

tinerrr:


I have doubts about how to interpretate this chart properly.
The question in simple. If we are cleared for the aproach and shoot it from TUM VOR. We will proceed outbound R- 186 and the question is: Should we maintain 2200`until stablished on the localizer? or, May we descend to 1700' even during the procedure turn and not stablized on the localizer yet?

I didnīt find the jeppesen chart on internet to be able to post it here. Thereīs a note on the current jeppesen chart on the 2200' altitude that says "recommended". I understand than if the altitud is recommended is not a mandatory minimum altitude, am I wrong?

Would this note change your answers?
I found the USAF chart here:

http://www.costaricaaviation.com/cha...ILS_RWY_3R.PDF


The minimum altitude for the teardrop is 2,200 (starting at not less than 3,100 at AT LMM or TUM VOR if AT is inop). 1,700 does not apply until established on the localizer inbound. The turn inbound on the teardrop should be commenced so as to not exceed 11 I-NAT DME. The TBG 8 DME is the stepdown fix (2200 to 1700) for the straight-in initial approach segment from TBG VOR.

The precision FAF is at 1700 at LAMBI, which is the 5 I-NAT DME (or radar fix).

This is a standard teardrop procedure turn portrayal. The underscored 2200 is a minimum alitude for the maneuver. The underscored 1700 is the minimum altitude on the localizer until G/S intercept.

I can't image Jeppesen having a recommended altitude for these circumstances.

welliewanger 19th Apr 2010 15:07

Reading betweent the lines
 
Take a look at the plate for the VOR procedure (13-1) After exiting the hold at 3100' the next altitude constraint is at LOMAR (same position as LAMBI) at 1600'.

Neither of the plates show the base turn intersecting the line for an altitude restriction at INAT / TUM10.

So, I would say that it would be safe to begin the descent to 1700' as soon as you leave the hold.

However, I would still probably stay up at 3100' until turning inbound since at 11nm the glidslope would be at 3500' so you would still intercept from beneath.

aterpster 19th Apr 2010 16:04


Take a look at the plate for the VOR procedure (13-1) After exiting the hold at 3100' the next altitude constraint is at LOMAR (same position as LAMBI) at 1600'.

Neither of the plates show the base turn intersecting the line for an altitude restriction at INAT / TUM10.

So, I would say that it would be safe to begin the descent to 1700' as soon as you leave the hold.

The altitude restriction for the teardrop is the same as the altitude restriction for the stepdown fix for the "NoPT" initial approach segment.

Descending below 2,200 before intercepting the localizer inside TBG 8/I-NAT 11 is absolutely wrong.

When do you leave a procedure turn completion altitude in the U.S.?

http://aeronav.faa.gov/d-tpp/1004/00504ILZ19.PDF

seilfly 19th Apr 2010 21:45


When do you leave a procedure turn completion altitude in the U.S.?
When established inbound - or was that a rhetorical question? ;)

welliewanger 20th Apr 2010 08:14


When do you leave a procedure turn completion altitude in the U.S.?
What does the US have to do with it?

It's a base turn, not a procedure turn. As discussed here:
http://www.pprune.org/questions/3929...dure-turn.html


The altitude restriction for the teardrop is the same as the altitude restriction for the stepdown fix for the "NoPT" initial approach segment.
Where does it say this? On the plate I'm looking at the line from TUM does not intersect the vertical line at INAT11. In fact it is not horizontal, it slopes downwards on the outbound leg.

aterpster 23rd Apr 2010 14:22

Welliewagner:

What does the US have to do with it?
Because course reversals are provided to provide essentially the same approach segment, whether in PANS-OPS or TERPS.


It's a base turn, not a procedure turn. As discussed here:
Base vs. Procedure Turn
You are hung up on symatics. A Base Turn in PANS-OPS is identical to a teardrop procedure turn in TERPS criteria.


Where does it say this? On the plate I'm looking at the line from TUM does not intersect the vertical line at INAT11. In fact it is not horizontal, it slopes downwards on the outbound leg.
It doesn't "say it," it portrays it graphically. The outbound AT NDB 186 bearing begins at not less than 3,100 and slopes downward to the course reversal maneuver completion altitude of 2,200, which is the minimum altitude until established on the localizer inbound.

Also, the teardrop outbound descent is predicated on the AT NDB, not the TUM VOR. The TUM VOR is authorized by the planview note only when the AT NDB is unsuable.

aterpster 28th Apr 2010 14:50

Current Jeppesen chart:

http://i201.photobucket.com/albums/a...JeppILS03R.jpg

EMB170 28th Apr 2010 16:38

Looking at the jepp chart, i would descent to 1700' if i'll do the procedure and, step descent to 2200' if i'll approach from TBG.
Looking at the chart it looks to me that the island where the TBG stands on is 1007' high and that is the reason for the step descent .


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