Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

When is an approach complete?

Tech Log The very best in practical technical discussion on the web

When is an approach complete?

Old 23rd Dec 2012, 19:51
  #1 (permalink)  
Thread Starter
 
Join Date: Dec 2001
Location: UK
Posts: 61
Likes: 0
Received 0 Likes on 0 Posts
Question When is an approach complete?

I would like to survey pilots' opinions as to when a Cat I/II/III approach is complete. Is it at decision height? Is it after the aircraft has landed? Is it as the aircraft exits the runway onto the taxiway system. When is it?

Many thanks.

RE
Razors Edge is offline  
Old 23rd Dec 2012, 20:18
  #2 (permalink)  
 
Join Date: May 2000
Location: Seattle
Posts: 3,195
Likes: 0
Received 0 Likes on 0 Posts
When the chocks are in place. The hardest part of Cat III conditions is taxiing.
Intruder is offline  
Old 23rd Dec 2012, 20:31
  #3 (permalink)  

Dog Tired
 
Join Date: Oct 2001
Location: uk
Posts: 1,688
Likes: 0
Received 1 Like on 1 Post
Int has it.

An approach is complete when the park brake is set.
fantom is offline  
Old 23rd Dec 2012, 23:09
  #4 (permalink)  
Mistrust in Management
 
Join Date: Mar 2000
Location: UK
Posts: 973
Received 0 Likes on 0 Posts
I don't really agree with both of those replies, however I think I understand where Fantom and Intruder are coming from.

An approach to landing is just that. The approach finishes when touchdown occurs whatever the weather conditions.

During Cat3b conditions rollout guidance is given until the runway turnoff - so one could argue that you have full autoland protection up and until that point.

I agree with the sentiment of the replies in that the very difficult part is then taxiing to the stand.


Regards
Exeng
exeng is offline  
Old 23rd Dec 2012, 23:19
  #5 (permalink)  
 
Join Date: Jan 2008
Location: ...
Posts: 3,753
Likes: 0
Received 0 Likes on 0 Posts
The approach ends when the crew selects reverse or selects TOGA. After that the aircraft has either landed or is going-around. But there are only two outcomes to an approach: landing or going around! (not counting crashing ok...)

With regard to cat 3b: landing rollout... Not approach rollout!

Lets not start confusing words here just to sound like smart-a****. For taxying there is a separate word... Taxying! Then there is also parking...

Is this a serious question??? Nobody thinks the work is done after the approach do they? Threats are different in every situation, so don't suddenly treat a cat3b approach the same as low-vis taxying.

Last edited by 737Jock; 23rd Dec 2012 at 23:25.
737Jock is offline  
Old 23rd Dec 2012, 23:28
  #6 (permalink)  
 
Join Date: Mar 2012
Location: Dark Side of the Moon
Posts: 1,418
Received 194 Likes on 64 Posts
Guess it depends who you talk to. When I did my original IR test around 12 years ago the examiner (UK CAA) was very clear in stating that under the regulations in the UK the 'approaches' were complete at the DA / MDA, if you went around then that was the Go Around Phase, if you continued to land then that forms part of the landing assessment i.e. you can fly a perfect ILS to the DA and then cock up the landing, that would be judged as a pass grade for the ILS but a resit for the landing assesment.

So in answer to the above I would consider that the approach starts at the IAF and finishes at the applicable minima, in the case of a CAT III that would be at wheel touchdown when NO DA.
Ollie Onion is offline  
Old 23rd Dec 2012, 23:47
  #7 (permalink)  
 
Join Date: Jul 2001
Location: Australia
Posts: 4,955
Likes: 0
Received 1 Like on 1 Post
Folks,
There are the practicalities and the legalities.
The UK Examiner is right, but only in terms of the phases of the approach and missed approach. -- effectively the various PANS/OPS segments.
When you are "cleared for approach", the clearance limit is the runway threshold, that is where the approach ends and the landing starts. Sorry I can't give you a reference, time-wise, it is too close to Christmas.
Tootle pip!!
LeadSled is offline  
Old 24th Dec 2012, 00:29
  #8 (permalink)  
 
Join Date: Jan 2006
Location: Between a rock and a hard place
Posts: 1,262
Likes: 0
Received 0 Likes on 0 Posts
The approach usually ends with a phone number or a rejection … occasionally you make it to the landing strip
172_driver is offline  
Old 26th Dec 2012, 03:05
  #9 (permalink)  
 
Join Date: Jun 2010
Location: Canada
Age: 37
Posts: 382
Likes: 0
Received 0 Likes on 0 Posts
Thinking from an examiner standpoint.

There are two phases here: approach and landing.

So where does the approach end and the landing phase begin? For a NPA, the approach ends the moment you leave the MDA for the field, or once you reach the MAP - which is where the missed approach segment starts. For a precision approach or APV, the approach ends once you reach DA(H) - the landing starts if you're visual at that point or the missed approach segment starts at DA(H) with no contact.
italia458 is offline  
Old 26th Dec 2012, 14:43
  #10 (permalink)  
 
Join Date: Jun 2000
Location: last time I looked I was still here.
Posts: 4,507
Likes: 0
Received 0 Likes on 0 Posts
I would consider consulting the accident/incident report forms. On these it asks you to state the phase of flight. You'll note approach, landing, G/A, taxying and others. I'd agree that the approach phase ends when you descend below the applicable minima. There you enter the landing phase. if you decide not to go below you've entered the G/A phase. After vacating the rwy you've entered the taxying phase.
RAT 5 is offline  
Old 26th Dec 2012, 22:12
  #11 (permalink)  
 
Join Date: Jan 2005
Location: uk
Posts: 280
Received 0 Likes on 0 Posts
I think that, in purely technical terms an 'approach', in CAT 1 or better, could be considered to be complete either 1) at the transition to visual reference or 2) at the point of go-round. However, during low vis ops, any approach is part of 'the system' that involves traffic spacing on approach and protection of the ILS signal environment around the runway. I would therefore suggest that under low vis ops your approach is not complete until you either carry out a go round, or until you have cleared the signal protection area around the runway after landing.

Last edited by 777fly; 26th Dec 2012 at 22:13.
777fly is offline  
Old 27th Dec 2012, 02:23
  #12 (permalink)  
 
Join Date: Jul 2001
Location: Australia
Posts: 4,955
Likes: 0
Received 1 Like on 1 Post
Folks,
Perhaps I didn't make myself sufficiently clear in an earlier post, to here goes again:

Are you referring to the segments of an approach, as per ICAO Doc 8168, or what ATC means by an approach.

Even with doc. 8168 procedures, if you have the required visual segment at minima, whether DA or MDA (not applicable for some Cat 111) the continued descent to the runway is still part of the approach, it is the visual segment of the instrument approach procedure. This just a strue for a straight in as a visual circling as a segment of an instrument approach.

As far as ATC is concerned, "cleared for approach" means your clearance limit is the threshold, until you get a landing clearance.

An instrument approach is only terminated at the DA/MDA if you commence a missed approach.

Thus, it seems to me that the ATC "definition" of approach, and an approach as an an instrument procedure, including the visual segment of the instrument procedure, are entirely consistent.

Tootle pip!!
LeadSled is offline  
Old 27th Dec 2012, 03:02
  #13 (permalink)  
 
Join Date: Jun 2010
Location: Canada
Age: 37
Posts: 382
Likes: 0
Received 0 Likes on 0 Posts
Even with doc. 8168 procedures, if you have the required visual segment at minima, whether DA or MDA (not applicable for some Cat 111) the continued descent to the runway is still part of the approach, it is the visual segment of the instrument approach procedure. This just a strue for a straight in as a visual circling as a segment of an instrument approach.
I agree that it's the visual segment of the approach, but the visual segment could also start well before the DA or MDA, once the aircraft has visual reference to some part of the runway environment. At some point there needs to be a landing phase!

As far as ATC is concerned, "cleared for approach" means your clearance limit is the threshold, until you get a landing clearance.
I don't think so. When you're cleared for an approach, your clearance limit is the missed approach holding point. Obviously if you receive landing clearance, you're allowed to land if you have the runway visual - obeying all the rules associated.

An instrument approach is only terminated at the DA/MDA if you commence a missed approach.
I don't think so. The instrument approach procedure is terminated at the missed approach holding point, which is the clearance limit. The missed approach point is where you transition from the final approach segment to the missed approach segment - both part of the instrument approach procedure.
italia458 is offline  
Old 27th Dec 2012, 05:41
  #14 (permalink)  
 
Join Date: Jun 2005
Location: USA
Posts: 951
Likes: 0
Received 1 Like on 1 Post
Believe it or not ICAO actually has a document for that! It's called "phase of flight definitions"

This document describes the final approach sub-phase (as part of the IFR approach phase) as ending when the flare begins. Alternatively the missed approach phase may be commenced at any time during the approach. The approach phase begins at the IAF.

Various other entities may have other definitions geared to how they are used. Most of them would seem to be applicable to statistical or accident reporting.

Here's another one:

Airplane Flight Manuals include landing distance tables which describe the landing distance as being from a point 50' above the runway threshold until reaching a complete stop.

I'm sure there must be more...

westhawk
westhawk is offline  
Old 27th Dec 2012, 10:43
  #15 (permalink)  
 
Join Date: Jul 2001
Location: Australia
Posts: 4,955
Likes: 0
Received 1 Like on 1 Post
westhawk,
Thanks for that, and consistent with what I posted.

Italia 458,
Wherever you fly, your home CAA or whatever, have a look up your AIP, it will probably be there, it is also in Annex 10, Vol.2 somewhere: The phrase "cleared for approach" means the clearance limit is the threshold. Not any other point in space. Look it up to satisfy yourself. This sort of thing is basic, it is not a matter of opinion. You might also find it in UK CAA CAP 413.

The missed approach is certainly part of the "instrument procedure", but it is not part of the "approach". To go a little further back, phases of "approach", the "initial approach", the "intermediate approach", and the (final) approach, from the FAF/FAP, and terminating at the threshold/in the flare. The "missed approach" begins anywhere down the approach that the approach is discontinued, as Westhawk has noted. The design missed approach segment begins at the DH or MDA for the particular approach.

If you think your clearance limit when "cleared for approach" is the missed approach hold (if there is one) try a missed approach somewhere busy, and you will get a practical demonstration otherwise. For planning purposes, most CNS/ATM systems assume an approach will result in a landing, there is simply not enough airspace, at busy airports, to assume every approach will be a missed approach.

Particularly if the same runway is being used for arrivals and departures.

As to "visual segment" of an instrument approach, this is not the same thing as when you become visual somewhere on an actual approach, "visual segment" is part of the procedure design, and is fixed for a particular approach.

Tootle pip!!

Last edited by LeadSled; 27th Dec 2012 at 11:00.
LeadSled is offline  
Old 27th Dec 2012, 12:27
  #16 (permalink)  
Plumbum Pendular
 
Join Date: Aug 1999
Location: Avionics Bay
Age: 54
Posts: 1,117
Likes: 0
Received 0 Likes on 0 Posts
I would like to survey pilots' opinions as to when a Cat I/II/III approach is complete. Is it at decision height? Is it after the aircraft has landed? Is it as the aircraft exits the runway onto the taxiway system. When is it?
Why do you ask, if you gave your question some context it might be easier to answer?
fmgc is offline  
Old 27th Dec 2012, 12:58
  #17 (permalink)  
Guest
 
Join Date: Apr 2009
Location: On the Beach
Posts: 3,336
Likes: 0
Received 0 Likes on 0 Posts
LeadSled:

When you are "cleared for approach", the clearance limit is the runway threshold, that is where the approach ends and the landing starts. Sorry I can't give you a reference, time-wise, it is too close to Christmas.
Because there isn't any such reference.

A clearance for an instrument approach procedures has as it clearance limit the end point of the missed approach procedure.
aterpster is offline  
Old 27th Dec 2012, 19:38
  #18 (permalink)  
 
Join Date: Sep 2010
Location: earth
Posts: 1,341
Likes: 0
Received 0 Likes on 0 Posts
Aircraft are usually flying throughout rollout until a variable airspeed. I would say it is when the aircraft has come to a full stop or exited the taxi way. You can always get a tow to the gate.
grounded27 is offline  
Old 27th Dec 2012, 21:12
  #19 (permalink)  
 
Join Date: May 2000
Location: Seattle
Posts: 3,195
Likes: 0
Received 0 Likes on 0 Posts
Looking at the OP's question in full context, I stand by my original answer. Rollout guidance and SMGCS are unique to Cat II/III operations. While you might be pendantic and debate the definition of "approach" in FAA, PansOps, EU-Ops, or other documents, getting safely to the gate is a MAJOR consideration in Cat III operations.
Intruder is offline  
Old 27th Dec 2012, 22:03
  #20 (permalink)  
 
Join Date: Jun 2005
Location: USA
Posts: 951
Likes: 0
Received 1 Like on 1 Post
getting safely to the gate is a MAJOR consideration in Cat III operations.
And how about getting FROM the gate TO the runway during low visibility conditions? I'd say it's just as much of a challenge. If an operator is approved for 600 RVR departures, it's pretty likely that they'll encounter visibilities of LESS than that during the TAXI phase. Or is that part of the takeoff?

But I agree in spirit with what you're implying intruder. In fact low RVR isn't necessary to present effectively poor visibility types of challenges to taxiing safely to or from your parking position. Especially at night. Or while it's raining/snowing. The way some of the lighting on the airport can glare off of wet/snowy/icy surfaces and windshields might make you want to whip out the low vis taxi chart and request a new taxi route!

In any event the specific criteria defining different phases of flight vary somewhat according to who defines them and for what purpose. Accident statistical analysis, certain aviation regulations and operator SOPs all differentiate between classification of events or requirements according to "phase of flight". A separate taxonomy for each purpose and usage it seems. In flying as in normal life, I find the inconsistencies in the use of terminology to be the single biggest source of misunderstanding among my peers. As such, this little discussion certainly does no harm even though it can easily be seen as having devolved into esoteric pedantry.

westhawk
westhawk is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.