CIR renewal NDB appr.

[Capt Wally]

I wonder how many guys/gals out there realise that during an NDB approach for the issue/renewal of a rating requires that the the track of the NDB must be within +/- 5 degs before decent can be made regardless of whether it's outbound or inbound. Now before you all go off on a tangent here & say BS. It used to be that way exactly 'till they bought in the diff cats some years ago that obviously meant this requirement made no sense due to the diff outbound tracks anyway of the diff cats. I thought 'till just yesterday that on say a reversal procedure ( most cases within oz) so long as you where heading in a direction that was going to intercept the outbound track as depicted on the appr chart then decent to the next limiting ALT was permitted. Says as much in the pre-amble of the Jepps for instance ....BUT in CAO 4.2.1/ 3.5(nav aid procedure tolerances) says "that decent shall not be comenced until within the +/- 5 deg's tolerance for the NDB proceedure, or words to that effect". Doesn't say anywhere in that official document about outbound or inbound. Am sure a lot of you out there already knew this but I didn't, I have been following the Jepps procedures for years & afterall these are the documents most likely carried for such an event.

This is what I was told by the examining officer, an ex CASA guy. See we learn something everyday. Fortunetly where I work we always establish any track within the req tolerances prior to decent but I wasn't aware of the two different statements in the two diff doco's. Sure I've read the CAO's before reading just that but it didn't click then.

Now lets keep the statements here on a professional basis okay guys? Don't shoot the messenger:)

CW:)

[ForkTailedDrKiller]

Wally

My recollection over 20+ renewals is that what you say used to be the case but for the last X renewals I have only seriously bothered with the +/- 5o once inbound (ie within tolerance before commencing descent).

That said, outbound I do try to nail the required track, but the 5 either side has not been a fail/no fail item. This seems to have satisfied a number of ATOs over the last 10 years.

Dr :8

PS: About time we dumped the requirement for NDB approaches anyway. I only ever fly them for currency and renewals - GPS RNAV Apprs rule (George does them quite nicely!)

[Capt Wally]

same here Dr...............after many renewals this is the first time this has been brought to my attention. Even tho we ought not to use that less than accurate tracking allowance (by way of just a heading that's going to intercept the outbound trk) it's a buffer for those times when it's howling a gale, it's 3am & you have just done a few approaches prior to this one ! Once inbound it's always been the same.
The RNAV arrivals are great, but they can be dangerous with poor situational awaresness on some types of GPS displays.

Still anything that get's us visual while staying accurate & keeps us alive whilst doing it has to be good!

CW:)

[Lefthanded_Rock_Thrower]

Mr Jeppesen would disagree:

Terminal AU-20 Section 3.5

3.5.2 For an approach that incorporates a reversal proceedure....after the aircraft has:
* crossed the facility and is ( either ),
1) established on the specified track, "OR"
2) has turned to a heading to intercept the specified outbound track.

What your ATO ( ex CASA guy ) is stating as a fact, is not fact, perhaps his/her personal opinion.

Cheers

[Capt Wally]

Yes yr quite right there LRT but the Jepps gives you the option, not so the CAO's that's all I was trying to get across here. So I still feel he (ATO) is correct to some degree. Although you could argue the point am sure.

CW:)

[training wheels]

I thought 'till just yesterday that on say a reversal procedure ( most cases within oz) so long as you where heading in a direction that was going to intercept the outbound track as depicted on the appr chart then decent to the next limiting ALT was permitted. Says as much in the pre-amble of the Jepps for instance ....BUT in CAO 4.2.1/ 3.5(nav aid procedure tolerances) says "that decent shall not be comenced until within the +/- 5 deg's tolerance for the NDB proceedure, or words to that effect". Doesn't say anywhere in that official document about outbound or inbound.

This issue was discussed during my MECIR initial test. If you refer to AIP ENR 1.5 - 1.20.2, it says;

"the descent to the specified altitude may be commenced after the aircraft has crossed the fix or facility and is established on the specified track OR has turned to a heading to intercept the specified outbound track. The reversal procedure must be completed, again descending to any lower altitude specified. Further descent, after the reversal procedure MUST NOT BE STARTED until established on the inbound track."

I interpreted this as not having to be within +/- 5 degrees on the outbound leg before you can commence descent but you MUST be established (ie +/- 5 degrees) on the inbound track before commencing further descent to the MDA.

[Capt Wally]

Yr quite correct there training wheels we all know this & have read the Jepps many times b4 a renewal but I think most here are missing my point. Am not disputing what the likes of training wheels is quoting here it's B&W just the fact that the CAO's say it slightly differently.

I enjoy the fact that we discuss it here, afterall 'school' is never closed !

CW:)

[RUMBEAR]

Captain Wally,

As an ex ATO I would agree with the opinion of the examiner on your last renewal. Unfortunately at some point in history, the CAO and AIP/Jepp requirements have become miss matched. Some of you may recall in years gone by the AIP requirement was indeed outbound descent was not permitted until established (with 5 deg). Now we have a situation where technically the standard required under test is different than required in the everyday situation. To my knowledge most practically minded ATO apply the AIP standard, however in a court of law the CAO should probably be applied.

One of many examples of conflicts that exist in the Australian regulatory framework. :ugh:

[OZ Junglejet]

How many pilots/companies realise that there is no requiremnet to do an NDB approach for the CIR renewal, min requirement in VOR. NDB requirment went out the window early 2006.

[Centaurus]

Mr Jeppesen would disagree

Depends which of the two documents (Jepps or CAO) is considered the highest legal authority. I would suggest the CAO is the one to stick with. In any case one could argue it is sloppy airmanship not to be within the required CAO tolerance before commencing descent on the outbound leg. You could be a mile or so one side of the aid and take up an intercept heading with full scale off centre and still be legal by Jepps. Legal - but not pretty...:ok:

[landof4x]

Well I think you are all wrong.

You can't get socked just because you went outside 5 degrees whether it's outbound or inbound. It says SUSTAINED ERRORS people. You fly the approach, it wanders out to 7 degrees and you go "whoops, better fix that little fella up", make a positive correction without delay and get it back in, your fine.

The only reason he can sock you is if you go out to seven degrees and sit there fat dumb and happy and don't make a positive correction to fix it up ie. you SUSTAIN the error. If he doesn't know that then he should hand back his testing approval.

That's the problem with a lot of ATOs/CASA these days, not looking at the big picture.

[Capt Wally]

4X we hear what yr saying & most ATO's would be looking for just that, sustained errors that are not recognized or corrected, that's widely known by all whom at least instruct. BUT the CAO's are a legal document & don't mention 'sustained errors' anywhere. We`ALL ought to be doing it as per the CAO's IE within the tollerance allowed but have in recent times been able to apply what's written in the Jepps for Eg. to do otherwise. The surveying of these types of approaches am sure allow for a great deal more than the +/- 5 degs & like I said with the now diff outbound trks due to A/C cat this would obviously be the case.

RUMBEAR too true & that's exactly the point I am making here after it had been brought to my attention.

"OZ" no ones dissputing that fact. The NDB even tho almost outdated is still a uselful way of getting visual & for basic tracking. At the very least siuational awareness is during an NDB app better than most others, dissreagarding a moving map display that is.

I shall personally continue to conduct an NDB app to the best of my ability IE: within tolerances but am more aware now that the Reg's are the legal binding basis for our safety.

Please continue gentlemen, debate is healthy as long as we respect each others opinions here.:)

CW:)

[linedriva]

Without having the CAO's in front of me (Other side of the world now), does the CAO specify whether is descent restriction applies for the entire approach, or for the final approach portion?
I also agree with landof4x (you do know why it's called 4x, don't you?:)) Ducking for cover now.

[MOQ]

The requirements in Jeppesen relates to tracking tolerance allowed during an instrument approach procedure, where the requirements in CAO40.2.1 Appendix 1 paragraph 3 relates to tracking tolerance during an instrument rating test. They are two separate things.

As specified in Jeppesen, descent restriction is only applicable for the final segment of NDB approach, and the statement in CAO; “for NDB procedure, descent shall not be commenced unless established within this tolerance” should only apply to final segment of the approach also.

I can understand someone failing a test for sustained error greater than 5 degrees during outbound leg of NDB approach, but if descent was continued while on "a heading to intercept the specified outbound track", what rule is being broken? As far as I can see, both testing and procedure tolerance are still maintained.

[Howard Hughes]

How many pilots/companies realise that there is no requiremnet to do an NDB approach for the CIR renewal,
Not the airlines that's for sure, I mean they always insist on their new recruits demonstrating an NDB in the sim!:rolleyes:

[Capt Wally]

Interesting responses here that's for sure.

"Linedriva" The CAO's can't be that type specific seeing as there are numerous ways in which an NDB app has been designed.

"MOQ" interesting you believe that a test for the issue or renewal of an NDB app & an inst app procedure are 2 diff things. Yr correct as far as the statement goes 'during a test' but the tracking tolerances pertaining to that exact app are mentioned in the CAO's as diff. (my interpretation only) Test or actual I see the same risks esspecially if the test is conducted in actual IMC.
Still I appreciate the different beliefs of some in here.

Again as I mentioned in another post here the way I see it now after being shown the two diff statements (which I was aware off but never put the 2 together in my mind) is the way we used to do NDB app tollerance wise was as the CAO's state, no decent until established. But when they introduced the segregation of A/C due to speeds etc. known as catagories ABCD&E the original statement didn't make sense due to the diff outbound tracks anyway. So hence the requirment as stated in the Jepps for Eg. "or as long as a heading is maintained that is intercepting the outbound track decent is allowed to the next limiting ALT", or words to that effect now applies.

Like I said I'm not trying to say that one particular way is correct & the other incorrect it's just that there is , to me & others in here some ambiguity to the way the written word is interepted. I would have thought that the regulator (CASA) would be the ones to look too for an accurate explanation. We've all being doing the NDB app for years now like it says in the Jepps and am sure most will continue to do so but doing it 'better' can't be a bad thing now can it?:)

Please continue those that have other opinions.

CW:)

p.s.............remember in my original thread composition here 'don't shoot the messenger' !:)

[omniplasm]

Possibly a stupid question from a PPL half way through IR training - so hands up for a please don't shoot.

In several posts it seems to be that interception of an outbound track (maybe even inbound track?) is being discussed in a manner that suggests the NDB has not been over-flown initially - forgiveness please if I have misinterpreted this. Can this be done - with appropriate aids ie NDB plus DME? Can it be done with only an NDB (I can't see how given no time or distance info). I can see potential efficiency ie approaching from the direction of an inbound track or crosstrack if that means one doesn't have to a do a sector 1 or 2 holding pattern entry first - which is what I have done under instruction to date.

I do realise that NDB questions in real life are increasingly theoretical and that GPS/DME letdown or if minimums are below that RNAV approaches are the order of the day for regional non ILS approaches.

Thanks

[training wheels]

In several posts it seems to be that interception of an outbound track (maybe even inbound track?) is being discussed in a manner that suggests the NDB has not been over-flown initially - forgiveness please if I have misinterpreted this. Can this be done - with appropriate aids ie NDB plus DME?

For some NDB approaches in category A and B aircraft, the track prior to overflying the NDB is not the same as the outbound track (it may be different by 5 degrees or so) so you need to turn on to a heading to intercept the outbound track initially.

As for your second question, most NDB approaches use the NDB itself as the initial approach fix so you got to overfly it before you commence your approach. The Moorabbin NDB approach however has a few alternatives using the Melbourne VOR and DME for the IAF and so not needing to overfly the NDB before commencing the approach but examples such as this (as far as I know) are few.

[Jamair]

AFAIK in any documentary disagreement between CAO / AIP and any other source (such as Jepps), the AIP / CAO rules.

NDBs are quite useful, they are not particularly difficult and because the arow always points to the beacon, they are a great SA aid if you don't have a moving map GPS.

For sites with only a NDB, using the GPS in 'Hold' mode is also an excellent aid in track keeping and error anticipation / correction - basically turns the approach into a VOR approach.

[ForkTailedDrKiller]

Omniplasm - I can't think of any NDB approaches where you don't have to cross the aid initially. If you think about it, in the absence of ATC radar vectors or the use of other nav aids, station passage is the only way you have to fix your position with sufficient confidence to start the approach.

Lets face it, except for currency, renewals, navaid failure or the absence of another suitable approach, you wouldn't bother with an NDB Appr.

Dr :8

[MOQ]

Captain Wally,

interesting you believe that a test for the issue or renewal of an NDB app & an inst app procedure are 2 diff things. Yr correct as far as the statement goes 'during a test' but the tracking tolerances pertaining to that exact app are mentioned in the CAO's as diff. (my interpretation only) Test or actual I see the same risks esspecially if the test is conducted in actual IMC.

What I mean by "2 different standards" for IFR procedures and IFR test, is that one would be set for terrain/traffic/airspace separation, and another being measurement of applicants' flying skill.

For example, there is no prescribed tracking tolerance for en-route navigation (Jepps ATC 500 series 5.6.1), but the testing standard (CAO) requires the applicant to demonstrate 5 degrees or less.

I am not an expert in approach design, but how I read it is Jepps requirement; "descent may be commenced once on a heading to intercept out bound track" will provide terrain clearance. While the candidate is doing exactly that, aircraft may still be outside 5 degrees of outbound track. If this error is sustained (which is hard to do as aircraft is already on a heading to intercept outbound track), ATO could interpret this as not meeting testing standard.

I can't really see it anywhere in CAO40.2.1 talking about procedural standard, as the whole section is about "issue of an rating".

[Monopole]

I wonder how many guys/gals out there realise that during an NDB approach for the issue/renewal of a rating requires that the the track of the NDB must be within +/- 5 degs before decent
Capt Wally, are you talking about issue/renewal only, or for everyday approaches. CAO 40.2.1 does specifiaclly mention Instrument Rating Test. Buggered if I know why they would be differant to everyday flying.

I was always under the opinion that the AIPs/Jepps were just as legally binding, it was just that the CAOs were rather general on some topics and the AIPs/Jepps elaborated more on the everyday aspect of flying.

My input anyway :ok:

[landof4x]

4X we hear what yr saying & most ATO's would be looking for just that, sustained errors that are not recognized or corrected, that's widely known by all whom at least instruct. BUT the CAO's are a legal document & don't mention 'sustained errors' anywhere.


Okay.....:ugh:

Well here is the link to the CAOs.

http://www.casa.gov.au/download/orders/cao40/400201.pdf

In appendix 1, titled "Instrument Rating Test", scroll down to section 3 titled "Flight Tolerances".

It states,


Flight within specified tolerances is necessary for the applicant to be judged proficient in the required flying manoeuvres. There shall be no sustained errors in excess of the specified tolerances.


No sustained errors, is there in the CAOs, with regard to the instrument rating flight test.

Now for the main issue of this thread, I think many are reading too much into it. Australian Aviation Law states that CASA can issue further instructions to the Regulations. That's what the CAOs and AIP are. The AIP is one such document where CASA is providing further, or more detailed instructions on what the CAOs mean - for example, with regard to descent on track.

[Capt Wally]

Everyone here is bringing lots of good points derived from how they read the rules & regs. I'm not directly trying to dispute anyones perception on how they believe it to be done (tollerances) just attempting to understand why we seem to have 2 diff tollerances that are applied to the NDB app tracking whether it be under test conditions or in real life day to day experiences.
'landof4x you seem to be the one who is somewhat off on a diff train of thought which is fine, you obviously have read it all in detail & came up with what you believe is the case. Remember I didn't make up the rules, I didn't write them as shown & I haven't to date applied them any differently to most in here, 'till just recently that is when an approved testing officer showed me the differences. One reg is pertaining to 'flight tolerances' & the other is pertaining to 'procedure tolearances. The question is are they one & the same? Also remember these two sub headings are just that, two seperate headings with two different statements.
I take back my statement 'landof4x' that there isn't anywhere in the CAO's that doesn't mention sustained errors, for that I stand corrected but it makes no reference to such where 'procedure tolerances' are being promulgated.

Does it matter whether yr conducting general heading flight tolerances or an actual track keeping excercise as in the outbound leg of an app?
landof4x you bring good strong points to the debate here but they are, like mine & everyone elses in here just opinions & interpretations:)

Now this guy maybe right or wrong BUT seeing as he is the examiner & I was the candidate there needs to be a 'chief & an indian' on the day. Both ways would have yeilded a safe outcome I believe anyway. I believed it best to bring it to the troops for further discussion.

Lets hope that we stay civilized on this hey !

CW:)

[landof4x]

Yeah, completely agreed. I did somewhat go off on a tangent regarding sustained errors, but it's a real bee in my bonnet at the moment.

With regard to the outbound leg of a letdown procedure and when descent can be initiated, if you want a legal perspective to stand on all you would have to do is track down the law which states that the AIP is a valid document.

It's their oversight, not yours. You have completed an instrument approach in accordance with CASA instructions from the AIP. He can point out the difference in the documents to you purely for interests sake or to pass the time of day, but he can't sock you for following the AIP instructions.

[DraggingAir]

"For example, there is no prescribed tracking tolerance for en-route navigation (Jepps ATC 500 series 5.6.1)..."

I agree with MOQ. Tolerances are discussed in AIP/Jepps (ATC General Flight Procedures 5.4.1) as follows:

"Tolerances are applied to tracks to assess containment areas for the purposes of ensuring navigational integrity, separation from other traffic.....These tolerances are based on the assumption that the pilot will maintain track as closely as possible."

"The pilot in command must, at all times, take positive action to regain track as soon as a deviation from the correct track is recognized." (5.4.2)

Jepps then goes on to specify tolerances for track keeping/enroute navigation within CTA, however, these are only inferred by declaring that pilots must notify ATC if they are off track by prescribed amounts.

"... the pilot must immediately notify ATC if the aircraft is found to be off-track by any of the deviations described below..." (5.6.2)

"where track guidance is provided by NDB or Locator - +/- 5 deg or more from the specified bearing" (5.6.2 )

"NOTE: The values given above must not be interpreted as defining a sector within which the pilot is permitted to navigate" (5.6.2)

The only other reference I am aware of relating to track keeping for a pilot [B]OCTA is CTA avoidance insofar as a pilot:

"of an aircraft operating in Class "G" airspace, or to the VFR in Class "E" airspace, must apply appropriate tolerances to the flight path to ensure that controlled airspace, or restricted areas, are not infringed." (5.10.1)

"... the following navigational tolerances must be applied to the intended flight path......NDB +/- 6.9 degrees" (5.10.2).

In relation to where CAO 40.2.1 makes references to an "Instrument Rating Test", when I was teaching multi/IFR, we went through the requirements in Appendix I with each student very carefully as part of their test preparation, including the tracking tolerances (3.5) and the 'sustained errors' aspect. These are Instrument Rating test tolerances only and do not apply to normal enroute navigation, unless explicitly stated elsewhere, as far as I am aware.

Finally, reversal procedures with a base turn - as Jepps says "...the descent to the specified altitude may be commenced after the aircraft has crossed the fix or facility and is established on the specified track or has turned to a heading to intercept the specified outbound track." (Jepps Terminal 3.5.2 unless the copy I'm looking at is out of date). This differs from turning inbound during the reversal procedure turn, where the limiting procedure altitude must not be descended through until the aircraft is established on track (within 5 deg). That's certainly what we taught a few years ago.

DA

[wateroff]

Ah s*&* - we all better hand in our CIR! - Pot-a-to -freaking Pot-ah-to.

The guys that debate this crap are generally the ones that carry a full set of AIP around in the aircraft - not realising charts are AIPs!!

[Capt Wally]

No worries 'landof4x', I've enjoyed yr posts, well thought out, direct & relevant.

'Dragginair'.....good post, & a well put together list of references of what we already know as per the various regs.

'wateroff', yr coments are noted. The AIP charts have various notes in the pre-amble stating what's required. Some planes I have flown over the years have had a full set of the AIP in the aircrafts library kept onboard. Some thing are done professionally.

I guess more can be said here about this subject but in order for a new entrant to this thread to understand my original post & the possible alternate reasonings the whole thread would need to be read. Some threads run for sooooo long that we get lost with the original comment, still am sure someone will get a little heated under the collar:) Just reiterating here, I'm just the messenger, am simply putting fwd something that I recently have learned whether it be right or wrong.:)

CW:)

[Cap'n Arrr]

I once heard of a guy failing a renewal due to tracking tolerances.

Turning inbound on final approach, he rolled out within limits. However, due to quadrantal error, the needle moved outside the 5deg when he rolled level. ATO says FAIL, needless to say that particular ATO was not booked for the retest.

[Capt Wally]

..............yeah well that's open to a lot of conjecture what that ATO did, but that's another story for another time. An ATO's hardest task is to know/recognize the difference between poor airmanship and/or equipment inaccuracies & then act accordingly.

Tnxs guys for all the input here on the subject of tracking tolerances, I for one always do try to do it better every time, the words 'good enough' & 'professional' are worlds apart:)
Fly safe

CW:)

[Cap'n Arrr]

apologies, it wasnt quadrantal error at all, must have had a few.

It was coastal refraction.... he established inbound, but as he passed the coast....

I wouldnt have thought that would count as a SUSTAINED error, provided action was taken as soon as the discrepancy was noticed, especially considering you have no real way of knowing when you will pass over the coast.

[Capt Fathom]

Interesting .. that 5deg outbound thingy. I should read the rules more often!

Being an old fashioned sort of guy, I just get within the 5deg before descending outbound!

Maybe I should use the rules to my advantage and not be such a high achiever!

After all, close enough is good enough! :E

[Cap'n Arrr]

Nope... good enough means you pass the test. Professional means you still think you could/should have done better, and then go work on it.:ok:

[Centaurus]

Nope... good enough means you pass the test. Professional means you still think you could/should have done better, and then go work on it.

Agree. Like those pilots who seem unable to land on the centre-line of a runway. Invariably on one side or t'other. Safe maybe and doubtless legal - but oh so sloppy....