Hi All,
Got my IREX early next week and had a question regarding which MDA to use when flying an NDB approach but using the DME for distance info/vertical altimetry reference.

In Question 26 in Revision Exercise 5
I understand that there's a few things to consider here. Firstly, being the LSALT on the route, which in this case is 8700, the second being the 25NM MSA which is 8000, the 10nm MSA which is 5700 and then the MDA's. - this is where i'm a bit stuck

Since we're using the DME and the NDB. From what it says in the book - we look at the DME arrival procedures and since our inbound track to Cooma is 085 we fall under Sector C (all good so far) - the correct answer is 4250, and by looking at the graphical layout it the lowest shade before the NDB is the MDA.I'm assuming this comes from the "Circling Minima" (A,B: 4250-5.0). Does this mean 4250 from this "circling minima" becomes our new MDA and the 'new' vis is 5.0km? - What happens to the the MDA and Vis requirements on the table on the bottom of the NDB-Z page? the 3840 (752-4.3) for SI and 4150(1044-2.4) for Circling.

Am I right by saying that since its a ''DME'' Approach we disregard the MDA's and VIs on the NDB page and the new MDA becomes the one labelled "Circling Minima"

Help would be greatly appreciated, please let me know if I can clarify more.

Thanks in advance!

Hi all,
Sat IREX yesterday and passed comfortably. Thanks Bob for the great study guides, really simplified everything and got to the point.

To all those sitting IREX - if you have a thorough understanding of the concepts in the book you'll be fine. I recommend getting the online practice exams as they will be very beneficial, especially in identifying areas of weakness. As I went through the IREX book I read all the corresponding references in the AIP and highlighted them, I also tagged almost all the references bob mentioned. I had about 25 tags in the end and then once I was doing the online practice exams I narrowed it down to 10 tabs (which is what you're allowed) - make sure you know where to find things in the AIP.

The exam started off with alternate requirements and minimum fuel type questions. The TAFS I got weren't too bad, they may seem long but just use your ETA to filter out parts which don't apply to you. Remember the 30 minute buffer which applies to OPRs I found it beneficial to draw it out - if the weather is changing from "good" to "bad OPR applies 30 minutes before and vice versa.

A couple recency requirements - make sure you understand what is meant by a 2D approach and that an azimuth approach is your NDB. If you've flown off track know how to calculate your dead reckon position in regards to LSALTS (20% air distance + 5 nm). When doing a reversal procedure know when you can descend below the published height - once established. A few give always such as reading numbers of DAPs and ERSA. I got about 4 NDB/VOR questions that were pretty tricky but if you understand what Bob has taught you'll be fine. If you need an alternate due to lightning know what requirements apply to the lighting. I got a take off minima question regarding a 'qualifying aircraft' remember to check the DAPs as some airports specify their own minimas. 1 met question regarding icing and none on GNSS.

Overall if you put in the effort and understand the concepts rather than just answering the questions I'm confident to say you'll pass with no dramas.

Onwards to ATPLs.

Regards,
Ray

Hello, I am abit confused about the same question on for DME/GPS arrival in cooma.
the cicling minina in NDB is much lower than the DME, why not take the minina of the NDB? DME IS 4250 and NDB is 4050 and 3740.
im not getting it. exercise 5 question 26. can someone help me please

BUMP

Still a valid question, has arisen from a few people now, myself included. Could someone in the know please clarify this

The circling minimum for Cat B is 300 feet above the HIGHEST obstacle within the circling area. That's 2.68nm arcs on the threshold of each active runway joined by tangents. However the Runway NDB minimum and the DME/GPS Arrival minimum is based on the final inbound track or sector to the aid. That may not necessarily include the highest obstacle in the circling area.

I could be wrong but I think the confusion is coming from people (myself included) not understanding the wording of the question. The question asks the minimum height you may descend to BEFORE crossing the aid. So if using a DME/GNSS arrival procedure, this will get you lower than the MSA before crossing the aid. Whereas if you were simply using the NDB procedure, you would not be able to descend lower than the MSA before crossing the aid. Correct?

Yep, that's it