IFR: Missed approach tracking requirements

[THE IRON MAIDEN]

G'day all, a mate and I are having a debate with reguard to tracking requirements on Missed approaches.

where an approach says to "turn right onto a track of 070"
is this;

a) a Dead Reckoned track (taking into account wind) of 070 from whichever point the aircraft happens to be. IE: in nill wind the aircraft would simply turn onto a heading of 070. or;

b) a Track of 070 with refference to the VOR/NDB. ie. turn right and intercept the outbound track of 070.

Cheers

[Avid Aviator]

AIP says to fly a heading adjusted for wind affect, unless the track is specified on the approach plate to be referenced from a navaid.
To complicate matters, I have also seen procedures that specify "fly heading..." which I guess is different again. Can't think of an example in Australia off the top of my head, but guess this is usually only in a radar environment.

[G Limit]

My understanding would be that if the missed approach is defined as "track 030", it would have to mean from the MAP otherwise you could be tracking 030 from anywhere and thus not guaranteeing you obstacle clearance. The charts clearly show the missed approach track originating from the MAP. This is evidenced by comparing an NDB approach with the VOR approach at the same aerodrome. eg MEK. The MA track is depicted as originating from its respective aid. If you're not tracking from the aid it would normally give you a height to reach before the turn.

But if someone can clarify the BLN Sector A GPS arrival missed approach?? "Climb on track to 2400'. At 1000' turn as appropriate track 030 from BLN NDB" ??:confused:

[Jamair]

Missed Approach Procedures begin at the Missed Approach Point (MAPT). "Track 120" etc means a ground track (ie DR corrected for wind) of 120, from the MAPT. If the procedure requires a track to intercept an aid radial, it will say "turn left track 040 to intercept the 120 VOR radial", or "turn left and track 040 ref the VOR or NDB"

If you have totally cocked the approach, before the MAPT, then you climb while still tracking to the MAPT, before commencing the missed app procedure. If you are doing a missed app because you have lost azimuth (ie the aid has shagged it) then you climb on track (DR) to the MAPT and do the missed app.

[Wing Root]

Jamair,

So, just to clarify what you and everyone are saying...

Let's look at the Kempsey NDB RWY 22 approach.

KMP RWY 22 NDB (PDF) (http://www.airservices.gov.au/publications/current/dap/KMPNB01-101.pdf)

In the missed approach from overhead the NDB are we turning LEFT to TRACK 090 or are we turning FURTHER left of 090 to intercept the 090 track outbound from KMP? Because if as you say it's track 090 from the MAPt, that would make it the latter of tracking 090 from the NDB.

[THE IRON MAIDEN]

Jamair and Wing Root make a good point,

I should claraify that when i said "tracking with reference to the VOR/NDB" I meant that in the case where the MAPt is the VOR/NDB.

For approaches like,

Maitland GPS Arrival the MAPt is D2.3 WMD VOR and therefore the Missed Appraoch Track is a DR track form D2.3 WMD out at 270

or

Phillip Island NDB or VOR, again the MAPt is 5.0nm from the CWS VOR/NDB and therefore the missed approach track of 180 is from that point.

[Black81]

G'day Iron Maiden, For my first post.

The KMP RWY 22 NDB is a DR track, not a track from the aid. You can see that this is depicted quite clearly on the chart. As opposed to this;
http://www.airservices.gov.au/publications/current/dap/BCGNB02-102.pdf
where the missed approach track is clearly from the aid.

black :)

[OpsNormal]

Jamair is right onto it (as usual).... :ok:

Wing Root wrote:
In the missed approach from overhead the NDB are we turning LEFT to TRACK 090....

Yes. The text simply says: "turn left, track 090, climb to 3400", not: "turn left, intercept the 090 track, climb to 3400".

...or are we turning FURTHER left of 090 to intercept the 090 track outbound from KMP?

No, not in this case.

....Because if as you say it's track 090 from the MAPt, that would make it the latter of tracking 090 from the NDB.

The wording on the DAP's can sometimes lead to some thinking that, but usually a quick look at the visual depiction of the concept of that individual Missed Approach proceedure will set you straight again. The difference between the KMP one you've used there Wing Root, and the CG one Black81 has also used is a case in point/there to be seen. The only other issue that people get confused with as well is the difference between tracking over the ground (ie: flying a heading with allowance made for known wind) v's tracking from an aid. ENR 1.5 Para 1.22.1 refers.

The concept of the Missed Approach as depicted in AIP ENR 1.5-1.10.2 should possibly be expanded to avoid questions or mis-understandings like the above. We are all human and interpret the same words in different ways.

[Wing Root]

OpsNormal,

So it would seem the answer to The Iron Maiden's original question would be "It depends on the diagram"

Although looking into it further the missed approach instructions are subtly different for the two examples. For KMP it says

TURN LEFT, TRACK 090. CLIMB TO 3400FT.

As for the Gold Coast example it simply says

TRACK 360, CLIMB TO 3500FT

Am I reading too much into the fact that the Gold Coast procedure omits the instruction to TURN RIGHT and hence this particular procedure requires an interception of the 360 outbound?

[ForkTailedDrKiller]

Your reading WAY too much into this.

1) Take a look at the ADELAIDE NDB Appr into Parafield (first one I came across).

The Appr MAP is about half way between Adelaide and Parafield.

MISSED APCH: Turn LEFT, track 270. Climb to 3000'.

There is clearly NO intention for you to intercept anything.

It assumes that having flown the Appr that you will have some idea of the wind and therefore should be able to make a reasonable job of laying off some drift from a heading of 270 if required, in order to make good a track of 270.

2) In the case of the Gold Coast NDB / VOR, you would hang a left onto 090 and do your best to make good a track of 090 while on climb to 3500.

3) In the case of KMP above you would hang a left onto 090 and make good a track of 090 from where you are on completion of the turn. You DO NOT have to make good a track of 090 from the NDB.

4) Take a look at Cairns NDB-A or VOR-A

MISSED APCH: Turn LEFT, intercept and track CS VOR R-045 (045 bearing from CS NDB), climb to 4000 or as directed by ATC.

Pretty clear there what you are expected to do!

Dr :cool:

[Wing Root]

FTDK,

You have basically summed up my views before I read this thread. I think everyone is agreed that to fly the KMP NDB approach you don't need to track outbound on the NDB during the missed approach.

For me the issue now is how much do we read into diagrams like the Gold Coast one above where the missed approach track clearly showes a dead straight line from the aid when there is quite a significant heading change required. After some of the replies above I'm not sure what the answer is now.

[ForkTailedDrKiller]

"For me the issue now is how much do we read into diagrams like the Gold Coast one above where the missed approach track clearly showes a dead straight line from the aid when there is quite a significant heading change required"

MISSED APCH: Track 360. Climb to 350'.

There is NO confusion here! The fact that the 360 track line on the Jepp appears to be straight off the VOR is just a co-incidence.

Hold the MDA until you get a clear indication of station passage, start the missed Appr then turn right onto a heading (initially) of 360, correct that for known wind in order to make good a track over the ground of 360, climb to 3500.

There is absolutely NO need for more precise tracking relative to the aid cause - there's nothing out there but water!

Unlike Cairns (for example), where if you don't get the drift right you could go outside the safely parameters of the Missed Approach, and you might hit something.

Dr :cool:

[Wing Root]

FTDK,

You've convinced me. What do the rest think?

[topdrop]

FTDK is spot on the money.
Terrain separation in the missed approach procedures allow for a delay in the initial turn, the turn itself and then the track - so the missed approach splay designers use can get quite large after adding the tolerance of all those in.

[Death Pencil]

The missed approach track allows for a turn after missed approach point. Whether it is then a DR track or nav aid track depends on the chart.
Compare these two charts; the 05 VOR specifies that you need to track on the 042 radial.

AD 12 VOR: http://www.airservicesaustralia.com/publications/current/dap/PADVO03-106.pdf

AD 05 VOR: http://www.airservicesaustralia.com/publications/current/dap/PADVO01-106.pdf

If it doesn't specify a radial/bearing, it's a DR track... no need to turn further and 're-intercept'. Have a look at PANS-OPS.. the terrain/obstacle considerations for missed approaches reflect this.

The EDN ILS is a classic example of how navaid tracking in the missed approach isn't required.
http://www.airservicesaustralia.com/publications/current/dap/PEDII01-109.pdf
The chart doesn't show a further turn to intercept a track of 340... further, what would you track on? its an ILS... its not as if you can track on the 340 LLZ track.:hmm: the only other civilian aid is the ndb, and there is no mention of 'ndb required' or anything like that.


DP

[SB4200]

Sorry to drag this back up.

YSBK 11C NDB (http://www.airservices.gov.au/publications/pending/dap/SBKNB03-105.pdf)

So for this missed approach "when established on track 300" effectively/practiaclly means once you've rolled out on your drift heading?

Why do the MAPts appear to vary by 0.1NM between the plan and profile diagrams?

On a similar note when a procedure turn (http://www.airservices.gov.au/publications/pending/dap/PDNLO02-107.pdf) is required during the approach, I believe I'm correct in saying that it is not intended to intercept that track from the aid, only to turn onto a drift heading (DR track) immediately after passing over the navigation aid or fix. Confirm? I find Jepps more confusing in this regard as they often draw straight lines from the aid.

[ForkTailedDrKiller]

"So for this missed approach "when established on track 300" effectively/practiaclly means once you've rolled out on your drift heading?"

Yes, turn left to make good a track of 300 degrees.

"Why do the MAPts appear to vary by 0.1NM between the plan and profile diagrams?"

Can't see it! On my chart (Jepp) the MAP is 11.6 nm from the SY DME on both the plan and the profile.

"when a procedure turn (http://www.airservices.gov.au/publications/pending/dap/PDNLO02-107.pdf) is required during the approach .... it is not intended to intercept that track from the aid, only to turn onto a drift heading (DR track) immediately after passing over the navigation aid or fix"

If my interpretation of your question is correct, Yes!
But I am not entirely sure I have the question right. Give us a "fur'instance" chart!

Dr :cool:

[Centaurus]

The concept of the Missed Approach as depicted in AIP ENR 1.5-1.10.2 should possibly be expanded to avoid questions or mis-understandings like the above. We are all human and interpret the same words in different ways

On a similar vein, be careful if you are interviewed by some Asian airlines as they have different interpretations to what Australian trained pilots are used to from reading AIP.

For example: Asked the meaning or interpretation of the terminology "TEMPO", the candidate from Australia defined the term as described in AIP with regard to one hour's holding fuel. The Asian airline interview board were nonplussed - they had never heard of TEMPO in terms of fuel. One board member said to the candidate that the airline already had 30 minutes of holding fuel aboard (In Australia we call it Fixed Reserve, a term unheard of overseas)

So if you have an overseas interview coming up, make sure you first swot up local aviation terminology. In the case described above, the candidate was unsuccessful as he quoted all the correct AIP type answers except he used Australian AIP - not the local AIP.

[insertnamehere]

I have another interesting situation...

Where is the MAP on an ILS? I always thought it was at the DA, and that the MAP shown is for the LLZ approach.

If that is the case, if you elect to carry out a missed approach from halfway down the ILS (out of tolerance or whatever), how do you first track to your MAP before following the missed app. procedure?

[Cap'n Arrr]

Arrr, That is correct... the MAP on the charts is for the LLZ approach, use the DA for the ILS.

If ye be electin to discontinue the ILS (Missed Approach), then ye'll be losing your vertical guidance (glidepath), so it becomes a LLZ Missed Approach, in which case ye shall track to the MAP (usually the Middle Marker) via the Localiser, at which time ye'll continue the missed approach as per the chart. (Climb and track as required)

That be all from me, I be off to pillage!:}:}:}

Yarr!

[insertnamehere]

Nice one... Capt Arr.. that is a nice succinct way of explaining it. What happens though if the reason you have discontinued the approach is because you go out of tolerance on the LLZ? You obviously can't then use the localiser to track to the MAP....

[MaxspeedSlowdown]

If the localiser fails while on the approach, you must to DR your track to the Missed Approach Point, while climbing to the MAP ALT. Not really nice if it happens inside to OM, especially where there are hills right next to the runway.

Also other traffic might separating itself (or ATC in CTA) with your expected track via the procedure including the missed approach. Could get ugly if the procedure is not flown as published.

I have however seen some jets below LSALT well into the ILS approach require a MA due weather and turn immediately out to sea. If there is no other traffic is the safety of the aircraft at risk?......or the the Capt ensuring the safety of the aircraft by avoiding the hazardous weather. The later I would suppose.

[Death Pencil]

back to the original question...

one requirement for a missed approach is if the navaid is suspect/fails.

where would the logic be in basing a missed approach on a procedure which requries the nav aid for tracking?! :ugh:

DP

[archangel7]

Interesting point DP, I looked into the AIP's and couldn’t find an answer to your qn.. Let me know if you find an answer. My guess would be to make an initial climbing turn to the landing runway and circle overhead the aerodrome until you are above the MSA. I think it all really depends on the position of the aircraft at the time the aircraft's radio aid became suspect or failed. If you’re lucky enough to have a secondary ADF/VOR on board then use whatever navaid is working. I wouldn’t go flying in IMC with only one navaid on the ground or aircraft anyways. At least 2 ADF's or VOR's. what would happen If you arrived to the airport still in IMC, running low on fuel, with only one navaid and it fails? then you really have a problem!! ...:ugh::confused:

[Death Pencil]

If the aid became suspect/failed during the approach you would DR track to the MAPt then fly the MAP from there.

I think you're getting mixed up with losing visual reference while circling? where you would make the climbing turn towards the runway....

My point from my previous post, was looking more at why the MAP is a DR track... not a nav aid track.

[ForkTailedDrKiller]

I have never seen this as particularly complex.

There is clearly a "protected" area associated with the Approach when flown correctly. If you are unsure of any aspect of the approach at any time, put the aircraft in a max angle climb and follow the approach procedure (in plan but not profile) using your best DR until you reach either the MAP or the DP - and then follow the MA as published until back at the appropriate LSA.

Chances are you will not hit anything!

Dr :cool:

[archangel7]

Hey DP, I dont know if im geting mixed up or not, but how would you track to a MAPt if the ADF/VOR failed in IMC?

[ForkTailedDrKiller]

".... but how would you track to a MAPt if the ADF/VOR failed in IMC ...."

If it were me I would:

If outbound in the Appr - commence a climb back to the LSA while trying to stay within the safe area of the appr. ie continue to track outbound for the indicated time, turn in the same direction as indicated on the appr chart, track back towards the aid by best bet DR and continue to time inbound, if not at LSA when back roughly over the aid then carry out the MAP using DR to make good a track.

If anywhere else in the appr - same thing. Start a climb - follow the appr plan profile and MAP to the LSA.

This is all kinda academic really. Unlikely that anyone these days is going to be flying an appr in imc with just an ADF or VOR. Start a max angle climb and use your GPS to return to the aid and the LSA then go fly the RNAV Appr, which I would have been flying in the first place.

Dr :cool:

[Cap'n Arrr]

Good point Doc, so then if ye lose the LLZ as well, I be thinkin there are nay airports with ILS which be lacking in the VOR/NDB area, so then if ye lose the LLZ, the obvious course of action be to tune in the VOR or the NDB and be setting a course for that aid instead, on climb to the LSA.

If the NDB be yer only approach, I be thinkin of a safe track out away from yonder hills when the ****e be hitting the proverbial before I be departing the hold. Assuming an escape exists.:(

Arrr!

[UnderneathTheRadar]

Assuming you're kitted out for it, set the GPS to OBS mode on the aid and dial up the tracks.

Tracking tolerance not good enough for the approaches but it will keep you out of strife if it all goes pear shaped. Even a little bitty handheld should be capable of keeping you away from the hills.

UTR.

[Capt Fathom]

Two pages on how to conduct a missed approach!

Isn't this covered during training and the test?

Do we really need a Pprune Committee Meeting to work out what to do??? It's not rocket science!

Let go of Mummy's apron strings...! :E

[SB4200]

FTDK

So "fur'instance" (http://www.airservices.gov.au/publications/current/dap/PDNLO02-107.pdf)...

The 025 track after HWS - intercept it or turn on passage and DR? Jepp/DAP give different impressions.

On another note (should this be separate thread?)...

What approach/holding design criteria lead to having a minimum holding pattern altitude higher than the 10NM MSA? Example (http://www.airservices.gov.au/publications/current/dap/CORNB01-101.pdf).

Are the tolerances/allowances in the hold so great that they go outside 10NM? Is there some other reason?

If you were to use a holding altitude of 2500 in the case above you could shave 3 or 4 minutes off the approach procedure.

[ForkTailedDrKiller]

FTDK

So "fur'instance" (http://www.airservices.gov.au/publications/current/dap/PDNLO02-107.pdf)...

The 025 track after HWS - intercept it or turn on passage and DR? Jepp/DAP give different impressions.

1) The Airservices chart show an 80/260 degree procedure turn - after station passage turn left at Rate 1 onto 025 then turn back Rate 1 to the right onto 285. The Jepp chart shows a 45/180 degree procedure turn - after station passage turn left to make good a track of 060 for 1 min (Cat A & B) then rate 1 through 180 degrees to make good 240 then intercept 285.

On another note (should this be separate thread?)...

What approach/holding design criteria lead to having a minimum holding pattern altitude higher than the 10NM MSA? Example (http://www.airservices.gov.au/publications/current/dap/CORNB01-101.pdf).

Are the tolerances/allowances in the hold so great that they go outside 10NM? Is there some other reason?

2) That's how I figure it.

If you were to use a holding altitude of 2500 in the case above you could shave 3 or 4 minutes off the approach procedure.

3) If you are worried about shaving time off an approach - stick with VFR - many of those who have gone before you had their life cycle abruptly ended by CFIT.

Fly the procedure like she is writ!

Dr :cool:

[OzExpat]

Are the tolerances/allowances in the hold so great that they go outside 10NM? Is there some other reason?
It's not unusual for the protection area to extend beyond 10 NM from the navaid. Indeed, the 10 NM MSA includes a buffer area of a further 5 NM, so it considers all obstacles up to 15 NM from the navaid. The holding pattern has a secondary area (i.e. a buffer area) of 5 NM all around the primary protection area and it's often the secondary area of the holding pattern that protrudes beyond the 10 NM MSA protection area.

Thus, if there's an obstacle beyond 15 NM from the navaid and it's higher than any of the obstacles within that radius, the pattern altitude will be higher than the MSA.