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

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]

Originally Posted by Capt Wally

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.

[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...

[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!

[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]

Originally Posted by omniplasm

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