Go Around Procedures

[fred737]

A question for you Instrument Instructors out there.

If one does a go-around from DA on a ILS approach and the Missed Approach Procedure involves a turn does one have to fly straight ahead to the MAPt before commencing the turn.

Similarly on a Non Precision Approach, NDB;VOR; LOC or GPS LNAV approach, flown using the Continuous Decent method and the Missed Approach procedure involves a turn, having started the go around at MDA (or just above it so as not to descend below it) does one have to fly straight ahead to the MAPt before commencing the turn.

Thanks,

Fred

[IRRenewal]

Yes and yes

[beamer]

When you go to Innsbruck for the first time you may realise just why that is the case !

[chrisbl]

Just think this through. The missed approach procedure starts at the missed approach point so it does not make sense the start the procedure from anywhere other the missed approach point.

[DFC]

For non-precision approach it is very simple. The Missed Approach Point will always be specified and easily determined.

When flying a non-precision approach, no matter if using the CDFA or flying level at or above MDA, the missed approach point as published must be overflown during the missed approach.

The only possible exceptions to this could be where

a) The aircraft is at or above the minimum vectoring altitude and after being informed of the missed approach they issue an immediate vector.

b) The aircraft is above the applicable MSA and ATC approve a routing that doed not go via the MaPT.

c) The one OEI requirements make overflight of the MaPT impossible.

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In the case of the precision approach, the procedure is basically the same however, if you are flying an ILS you are left to determine at what point the glideslope intersects with the published DA - note I said published DA which could be lower that your personal or company minima.

If there is a DME then it is reasonably easy to determine where 200ft AAL is - about 2/3nm.

The rules in this case require that if a missed approach is started early, one still has to overfly the position where the glideslope intersects the DA.

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So let's look at ana example;

Sea level aerodrome

ILS procedure with DA 200ft

LOC (GS Out) procedure with MDA 400ft and MaPT at the on field NDB

Missed approach procedure is Straight ahead to 1000ft then left turn back to the LOM climbing to 2000ft

Your minima - DA500ft for ILS and MDA 600ft for LOC - using CDFA

In the case of the ILS the missed approach climb would be started at 500ft - (about 1.7nm) but even if the aircraft levels at 2000ft the left turn can not be made until 0.7 DME is passed because this is about where the published DA is.

For the LOC it is easy. Go arround at 600ft and start the turn at the NDB.

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The lesson to be learned is that when flying a precision approach one still needs to be aware of where the published DA lies despite using a higher value.

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Finally be aware. ATC may be expecting you to start the missefd approach at the published DA and may have based a non-standard missed approach instruction on this eg "straight ahead to 1000 then right turn heading 360" and might be a bit surprised if you manage to establish on heading 360 prior to passing the landing threshold!! - They shoulod not be but it can happen.

[Pull what]

If one does a go-around from DA on a ILS approach and the Missed Approach Procedure involves a turn does one have to fly straight ahead to the MAPt before commencing the turn.

A precision approach does not have a MAPt-a MAPt is a function of a non precision approach only. If you see an MAPt on an ILS plate it is for the localiser approach only.

[DFC]

A precision approach does not have a MAPt-a MAPt is a function of a non precision approach only

Partially correct.

On precision approach the missed approach point will where the nominal glide slope intersects the DA.

Similarly the final approach point is where the nominal glideslope intersects the intermediate altitude (platform altitude).

Since different operators may use different DA's then it is not possible to publish a common point.

Just because the missed approach point is not a fix doesn't mean that it does not exist.

[Dan Winterland]

I think the answers to the questions are:

1. Generally yes.

2. Yes in nearly every case with probably a couple of exceptions. (I can actually think of one).

As mentioned, any MAP for a PA has to have a notional MAP because of variences in operators minima and type of precision approach. For example, a CAT3B approach may not have a DA. Also, there may be local variences, for example, TERPs or PANSOPs.

A good clue is to see what aircraft with Flight Management Systems do. The approach will always terminate in a waypoint. For a PA, this is invariably the runway threshold and initiating a GA will sequence the Missed Approach waypoint string from this. Some NPAs will terminate at the threshold and some at the MAP. The procedures are written assuming the GA will be made at minima. So in the case of higher level GA, it's very safe to say that you should overfly the MAP or the runway threshold. Which depends on the procedure - and the approach plates should tell you in the case of a GA.

If the MAP is an on airfield beacon, this will not generally be the last waypoint as it may be displaced, and in anycase, the approach will not be stabilised. Many published approaches now have an RNAV overlay and the Flight Management Computer sequence the waypoints along this path.

In any case, the autoflight aircraft will invariably go into a runway track or heading mode after a GA and it's up to the pilot to engage some form of lateral managed navigation to make it happen. Of course, once the realisation has dawned the aircraft can't land and the GA initated with subsequent flap and gear retractions, this won't happen immediately, so there is usually some lattitude, even with very low level turns.

[DFC]

A good clue is to see what aircraft with Flight Management Systems do.

Dan,

While there are a variety of systems out there one common important thing is that one can never fly an ILS or LOC approach using the FMS.

This is critical.

To put it in GA terms - one can never use GPS to fly an ILS or LOC approach.

In most cases the ILS does not become an issue because even those in drastic need of help seem to remember to arm APP which couples the FD to the ILS (and not the fms).

The problem is when the GS is U/S and the "bright spark" thinks "I can do this in LNAV (FMS)" or "I can use the GPS".

This is dangerous.

The localiser gets more and more narrow as one gets closer to the threshold and therefore 1/2 scale deflection represents a smaller distance from the centreline at 1nm than at 5nm.

If one tries to use FMS LNAV / GPS then 1/2 scale deflection maintains a constant distance from the centreline and therefore one could leave the obstacle protected airspace.

As for the Missed approach. Generally, the missed approach becomes available for activation one one passes the FAF or FAP.

When one flies the approach one should set the heading bug appropriately. Therefore one initially has a heading to fly that will cause the aircraft to track straight ahead. Note I say straight ahead and not the runway centerline because the initial missed approach is a continuation of the final approach track and unless the tracking aid is on the runway centerline one will be flying across the centerline.

Having established the aircraft on the missed approach, if we arm LNAV then the FMS will cause the aircraft to track in accordance with the published missed approach procedure. The only time it will just leave you on a heading is when (just like on a SID or STAR) the procedure specifies that a heading is followed.

If the MAP is an on airfield beacon, this will not generally be the last waypoint as it may be displaced, and in anycase, the approach will not be stabilised.

I don't know what you are getting at here. The position of the MAPt has no relevance to stabilised approach criteria. We are now required to use CDFA (and I hope all schools are teaching it). No matter the type of straight in approach, the IMC stabilised criteria are normally determined at something like 1000ft AAL which will be a long way from the MApT (unless someone has mucked up the procedure!!

Finally the last thing I would ever recomend is to base what one does on what the FMS has coded into it. Quite common to have coding errors and also find that (as some people did in Chambery recently) that the FMS can ask that a turn is made in the wrong direction is you get the missed approach speed wrong.

If we could trust the FMS / GPS we would not spend all that time every flight cross checking the waypoints etc!!

[SNS3Guppy]

If one does a go-around from DA on a ILS approach and the Missed Approach Procedure involves a turn does one have to fly straight ahead to the MAPt before commencing the turn.

YES!!!

One may climb early, but not turn.

[Dan Winterland]

DFC, my illustrations were so that the questions raised could be answered and not for a discussion of how to manage a GA in an FMC equipped aircraft which is not really what this forum is for. But I will answer your points as I'm on standby and don't have much to do.

"While there are a variety of systems out there one common important thing is that one can never fly an ILS or LOC approach using the FMS."

You may be suprised to know that it is acceptable in at least one (and maybe some more) aviation authorities jurdisdiction to fly a LOC approach in NAV on certain aircraft types- as with any NPA. But if it doesn't have an RNAV overlay (as a LOC will not), raw data has to be displayed somewhere on the flightdeck.

"To put it in GA terms - one can never use GPS to fly an ILS or LOC approach".

Do you mean General Aviation or Go Around by your use of GA. If the first, no. The latter maybe. And FMS position derived from a mix of inertial, radio and GPS position and never from GPS alone.

"As for the Missed approach. Generally, the missed approach becomes available for activation one one passes the FAF or FAP".

Not on the aircraft from the airliner manufacturer who sold more than any other last year. It becomes active from the IAF, or when the approach is manully activated. If the MAP is an on airfield beacon, this will not generally be the last waypoint as it may be displaced, and in anycase, the approach will not be stabilised.

"When one flies the approach one should set the heading bug appropriately. Therefore one initially has a heading to fly that will cause the aircraft to track straight ahead. Note I say straight ahead and not the runway centerline because the initial missed approach is a continuation of the final approach track and unless the tracking aid is on the runway centerline one will be flying across the centerline".

You can't on an Airbus, well you can for 45 seconds, but there's no point. FMCs will specify which directional reference is active on a go around and apply it when the GA is initiated. They all do it differently and some even know which standard (TERPs or PANSOPs) the approach is using and apply the relevant technique.

"I don't know what you are getting at here. The position of the MAPt has no relevance to stabilised approach criteria."

The MAP in an FMS waypoint on a NPA with an RNAV overlay cannot be past the threshold, so there is another waypoint inserted before - either at the threshold or the MAP. It is relevant to stabilsed approaches as some types can fly NPAs fully managed, i.e in 3D. With both lateral and vertical navigation down to MDA.

I have used three very different FMCs in my career and they all do things differently. But one thing in common is that they all sequence waypoints when you get within certain parameters. It's crucial that the TO waypoint is relevant. If you are vectored on the approach and miss the TO waypoint without noticing it, your GA procedure may have you fly back to tthe waypoint you missed. If you activate the GA before you get to the MAP and there is another waypoint before the MAP, you need to make sure the GA track is flown from the MAP. Not a problem usually as the heading reference will usually be Runway Track or similar and you just need to make sure the NAV reference is activated with the MAP as the sart point for the GA procedure.

"Finally the last thing I would ever recomend is to base what one does on what the FMS has coded into it".

Well, I do. It's my company's SOPs and it will be the same with many others. The approach coded in the FMC is checked by each pilot from the approach plates. Every track, distance and constraint. And then we fly the approach with FMC guidance where relevant. However, usually, it's an ILS so from intercept, we are flying something other than FMC derived navigation. But we have a number of NPAs on our network, including a some GPS approaches (now referred to as RNAV) approaches, so we have no choice but to follow the FMC. An further to that, we can fly the approach fully managed. That is to say, we leave the autopilot in, when cleared for the procedure, we arm the approach and then watch the aircraft fly itself down to MDA just as if if were an ILS. All we have to do is click the autopilot out at the "Minimum" call and land it. And this isn't limited to RNAV approaches. We can do this on any NPA with an RNAV overlay. It's very safe, much safer than the pilots interpreting and chasing wobbling needle and we are encouraged to use this method rather than hand fly.

I don't know when you last flew an FMC, but things have changed.

[DFC]

DFC, my illustrations were so that the questions raised could be answered and not for a discussion of how to manage a GA in an FMC equipped aircraft which is not really what this forum is for.

Unfortunately, your "illustration" was rather confused wich does not help the reader and I think that this is the perfect forum for instructors and examiners and not limited to PPL level instruction.

Just some of the major points;

The MAP in an FMS waypoint on a NPA with an RNAV overlay cannot be past the threshold

1. There does not have to be an RNAV overlay for the NPA to be coded in the FMS.

2. The MAP can be past the threshold. However, if that is the case, then Virtual Glidepath or whatever your system calls it will not be available. i.e. you will get the normal LNAV indications but no VGP and will have to use some other vertical mode to follow the ideal profile as published for each mile on the chart.

3. GPS procedure - use GPS. RNAV - use any appropriate RNAV system. In most cases the FMS will use DME/DME and/or VOR/DME in addition to GPS so RNAV could be available when GPS is U/S ergo one could fly an RNav approach but not a GPS one.

As for the missed approach being available after the IAF - I again think that you are confusing being available rather than being available to be activated in accordance with normal procedures. Here is an important point related to the question posed - the missed approach must be started from the final approach track to ensure obstacle clearance.

If one starts a missed approach just after the IAF then unless one is cleared otherwise one follows the procedure to the MAPt. To do otherwise in many places could cuse one to fly into a mountain.

I am glad that you agree one should never use the FMS coded procedure without first checking that it is in accordance with the up to date chart and notams because we both agree that it is the chart that is what one follows be it by hand-flying raw data or sitting back and watching the aircraft do it for you.

Everyone needs to remember that no matter if you are flying a basic old PA34 on an instrument approach or the latest fly by wire FMS equipped aircraft it is the pilot that needs to know what is happening and about to happen because making an incorect decision eg early turn will put an Airbus into the mountain just the same as the PA34.

So to sum it up - do what the chart says. If there is any doubt then do not let the FMS database programmer become PIC!!

[Pull what]

Quote:
If one does a go-around from DA on a ILS approach and the Missed Approach Procedure involves a turn does one have to fly straight ahead to the MAPt before commencing the turn.

YES!!!

One may climb early, but not turn.

No-because there is not a chart MAPt on a precision approach as per PANS OPS
You follow the missed approach procedure (or ATC instructions) if an early turn is not allowed the missed approach procedure will make that statement

[samusi01]

I was taught not to turn until reaching the MAP or point at which DH/DA would normally be found. Consequently, my students have been taught the same. The FAA's guidance on the matter, per AIM 5-4-21:

Obstacle protection for missed approach is predicated on the missed approach being initiated at the decision altitude/height (DA/H) or at the missed approach point and not lower than minimum descent altitude (MDA).

Therefore, on an approach predicated on TERPS, an early turn below MSA/TAA or equivalent may result in loss of separation, as you are no longer operating at an altitude that has been surveyed.

[Dan Winterland]

DFC, Another standby day, so I'm going to answer. WRTo FMS overlays. It depends on the provider of your navigation database, but you will find these days that a RNAV overlay is generally required for a NPA to be included in the FMC as an available approach. Nearly every NPA in my company's route structure now has an overlay and suitably coded waypoints. You still find some which don't in the approach book, the older NDB A and B procedures which require timing outbound, but these are not in the FMC database. You can of course build these youself or fly them on raw data, but neither technique is recommended and has in fact been recently disallowed by my company's SOPs. The one exception of course is a LOC approach, but this uses the ILS as the selected approach in the FMC.

Ergo, any NPA with an RNAV overlay with a pulished MAP of a beacon past the threshold will have a termination waypoint at the runway threshold or another waypoint before the threshold to make it work. A managed approach with vertical guidance is not possible in this case.

GPS approaches are becoming known as RNAV approaches. I think this is to discourage pilots flying them with standalone or inappropriate GPS set which has caused a few accidents I gather. It depends on the equipment fitted, but in our operation we must have GPS navigation in High accuracy on all FMCs to commence the approach. If you haven't then you will almost certainly not have the RNP to commence the approach. (Our FMCs dispaly the RNP and ANP - Actual Nav Performance values). Flying a RNAV approach without GPS updating is not allowed within our SOPs

The Missed Approach procedure becomes active after the IAF, it is included in the waypoint string from the last waypoint on the approach. Initiating it depends on aircraft type, I can't remember how to do it on glass cockpit Boeings - it's been several years since I last flew them. But in the Airbus, you select TOGA (even if you don't want TOGA power - you just immediately bring the Thrust Levers back to the Climb detent before the engines respond) and the aircraft will go into a heading refrence mode. It's up to the pilot to reselect a NAV mode and ensure the TO waypoint is the one he wants and that the sequence follows the procedure. It will never fly you direct to the start of the Missed Approach Procedure unless it it the TO waypoint. In my experience, ATC will invariably give you a radar heading on a GA anyway, so being in a heading mode is probably best.


Apologies for the thread creep to all those of you who seek the answer to the original question.

I think it's been answered BTW!

[DFC]

You can of course build these youself

One must never build one's own procedure. If it is not in the database then it can not be used. If for no other reason than you have no way of ensuring that the sensitivity of the CDI changes appropriately for the various phases of the operation. Your company's SOPs are merely following what has been a requirement for a very long time.

Perhaps you (in common with many others) are confusing using the FMS to fly an RNAV approach and using the FMS to fly a series of tracks that you are using to fly an approach based on raw data i.e. the FMS is doing all the brain-work but the only reference for the approach is the raw data. You could do just the same by flying in Heading mode and working out the required headings yourself.

and the aircraft will go into a heading refrence mode

Ah we agree. As I said previously, the initial missed approach is in heading mode and provided one has set the heading bug to a figure that will maintain the final approach track then the initial missed approach will track straight ahead (an extension of the final approach track) as per the requirements.

The most important thing about GPS approaches is RAIM.

I think this is to discourage pilots flying them with standalone or inappropriate GPS set

It is entirely legal and common for aircraft to use a single (approved) GPS unit for GPS approaches.

It is also entirely legal and common for aircraft with no GPS to perform RNAV approach procedures (based on VOR/DME).

If I remember correctly the only time one needs an FMC (FMS) is when doing DME/DME procedures.

However, no matter what one is using to work out where to point the nose of the aircraft it remains the responsibility of the PIC to ensure the safety of the flight and this means following the relevant approach procedure correctly.

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Pull What,

No-because there is not a chart MAPt on a precision approach as per PANS OPS
You follow the missed approach procedure (or ATC instructions) if an early turn is not allowed the missed approach procedure will make that statement

Originally Posted by PANS OPS

6.1.4 It is expected that the pilot will fly the missed approach procedure as published. If a missed approach is

Originally Posted by PANS OPS

initiated before arriving at the missed approach point (MAPt), the pilot will normally proceed to the MAPt (or to the middle marker fix or specified DME distance for precision approach procedures) and then follow the missed approach procedure in order to remain within the protected airspace.

Originally Posted by PANS OPS

Originally Posted by PANS OPS

Note 1.— This does not preclude flying over the MAPt at an altitude/height greater than that required by the
procedure.

Note 2.— In the case of a missed approach with a turn at an altitude/height, when an operational need exists, an
additional protection is provided for the safeguarding of early turns. When it is not possible, a note is published on the
profile view of the approach chart to specify that turns must not commence before the MAPt (or before an equivalent

point in the case of a precision approach).

The above is from PANS-OPS. In the second note I have highlighted the important words - when an operational need exists. You will not normally know when this is and there are many places where turning before the MApT would turn you into the side of a mountain. This also only applies to a turning missed approach where the turn is at an altitude.

To keep safe, unless you are sure of obstacle clearance and have ATC clearance then always overfly the MAPt.

[Dan Winterland]

"One must never build one's own procedure. If it is not in the database then it can not be used."

I'm not advocating building your own procedure! If it's published and not in the database, it's possible and legal withinin some authorites rules and regulations to build it from the approach plate. It should be checked independantly by both pilots and it has to be flown selected, not managed (if managed approaches are legal on your type/Authority/AOC).

''Perhaps you (in common with many others) are confusing using the FMS to fly an RNAV approach and using the FMS to fly a series of tracks that you are using to fly an approach based on raw data''

No, I'm not. The FMS flys a RNAV overlay NPA through a series of waypoints coded in the FMC. The raw data is there and has to be displayed, but we are essentially flying an RNAV approach (not to be consfused with a RNAV GPS approach) from the database. The raw data is now largely irrelevant. The old approach has been converted into a more mangeable and safer procedure. I've posted an example of an RNAV overlay NPA below.



The faint references in the square brackets are the RNAV waypoints and are coded as such in the FMC. In this case, the approach can be flown fully managed in aircaft so certified. i.e - it can be flown with a 3D profile with vertical guidance in automatic flight just as an ILS would be

There is no confusing of anything. This is a certifed and authorised method and is now the primary technique for flying such approaches with many operators.



Incidently, this is an example of an approach which does not terminate at the threshold, but the MAP. So in this case, the missed approach should be initiated from the MAP, if the decision to go around is made before or at the MAP.

[Pull what]

DFC -- It doesnt matter how many times you quote PANS Ops or make other statemements, a precision approach does not contain an MAPt!

To keep safe, unless you are sure of obstacle clearance and have ATC clearance then always overfly the MAPt.

You keep quoting an MAPt-it doesnt exist for a precision approach as your posted Pans Ops example shews. You proceed to the MKR or published DME distance, as you have quoted. So to recap again what I said, in the event of a missed approach on a precision approach you follow the published procedure, if an early turn is not allowed that will be written into the procedure by direct statement or DME distance.

If one does a go-around from DA on a ILS approach and the Missed Approach Procedure involves a turn does one have to fly straight ahead to the MAPt before commencing the turn.

That was the original question, the answer is NO because there isnt a published MAPt on a precision approach and as your example shews, you fly to a stated DME distance or to a MKR. the only way the pilot knows this is by an associated statement with the GA procedure.

when an operational need exists. You will not normally know when this is

Not sure what you mean by that-how are you interpreting an operational need?

[DFC]

DFC -- It doesnt matter how many times you quote PANS Ops or make other statemements, a precision approach does not contain an MAPt!

Every instrument approach has a missed approach point.

Originally Posted by PANS OPS

Missed approach point (MAPt).

Originally Posted by PANS OPS

That point in an instrument approach procedure at or before which the prescribed

Originally Posted by PANS OPS

missed approach procedure must be initiated in order to ensure that the minimum obstacle clearance is not

infringed.

QUOTE=PANS OPS] 6.1.5 The MAPt in a procedure may be defined by:

a) the point of intersection of an electronic glide path with the applicable DA/H in APV or precision approaches;
or
b) a navigation facility, a fix, or a specified distance from the final approach fix (FAF) in non-precision

approaches.[/quote]

Just because it is not charted and/or is not a fix does not mean that the missed approach point does not exist.

Everyone needs to be aware of where the missed approach point is on every precision approach that they fly. The reason is that starting the missed approach later than the missed approach point can cause a loss of obstacle clearance. Note well that when you fly an ILS the missed approach point is the intersection of the nominal glide path and the decision altitude.

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Dan,

You could have picked an example outside the Former USSR / China countries!!

You could even have left people with some clue about where you are talking about if you wanted to discuss the matter.

Give us an example of an Authority that permitts a pilot to construct an approach procedure in their FMC or GPS and then fly that procedure. Perhaps you could explain to us how when flying such a procedure you ensure the automtaic changes in RAIM requirements and CDI scale.

[Dan Winterland]

I could have, but it doesn't matter where the procedure is. I used it as I happened to have the plate stored on my hard drive as this approach was the subject of a recent OPC. It exists and it's topical. This plate is one of my company's daily destinations in China - and I have flown there in the last week.

RAIM will not have any effect on the accuracy of the information displayed. If a lack of satellite coverage was an issue, then the degradation in Nav accuracy will be annunciated and an alternative method will have to be chosen. As for a CDI range, no aircaft equipped for such an approach will be fitted with a CDI these days. It will have an ND which will have it's range manually selected by the pilot according to personal preference or SOPs.



DFC, I don't know what your experience or background is, but either you are an ex-airline pilot who is out of date with the current techniques and equipment, or an instructor who thinks he knows it all. Either way it's clear that you don't fully understand what you profess to know.