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RNAV Minima

  • mzucchetto
  • Topic Author

mzucchetto created the topic: RNAV Minima

Hey all

Working through the Bob Tait IREX book at the moment and am stuck on the Minima stated in the RNAV examples in the book (Flinders Island and Bathurst).
I have the October 2014 book and have checked the errata for any changes in regards to this.
On my page 261 (RNAV (GNSS) 2D Approach), paragraph 5:

"For a landing on runway 05, the aircraft must be clear of cloud by 570ft with a visibility of 3.1km by the missed approach waypoint [FLIWM]"

On the chart shown in the book as well as the current DAPs, the straight in GNSS minima is 620ft with 3.4km vis (a difference of 50ft height and 300m of vis). Boxes are shaded therefore minima can be reduced by 100ft if AWIS QNH has been received in last 15mins, making it 520ft. If using TAF forecast QNH then stays at 620ft, and if using Area QNH increased by 50ft to 670ft.


Over a couple of pages to 265/266 (RNAV runway 17 approach into Bathurst).
"to land on runway 17, we must be clear of cloud by 3070 feet AMSL (649ft AGL) and have an in-flight visibility of at least 3.7 km. So, levelling off at MDA, we hope to become visual if not visual already."

On charts shown in the book, the straight in GNSS minima is 3040ft with 3.7km vis (a difference of 30ft height). Boxes are shaded therefore minima can be reduced by 100ft if AWIS QNH has been received in last 15mins, making it 2940ft. If using TAF forecast QNH then stays at 3040ft, and if using Area QNH increased by 50ft to 3090ft.
The 649ft AGL + Threshold Elevation of 2391ft gives us 3040ft.

If anyone can shed some light on this, that would be greatly appreciated. I'm sure I've missed something somewhere and I'll feel silly once it's pointed out to me :P , but I haven't been able to find it in the text or AIP.

Thanks in advanced
Mark
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bobtait replied the topic: RNAV Minima

Gidday Mark

The changes from 570 feet to 520 feet and the change from 3070 feet to 3040 feet were due to an updated approach plate when I failed to change the associated text. The text has now been changed to 520 feet and 3040 feet respectively and an errata has been posted to reflect that. Thanks for your feed back, it is most appreciated.

Bob
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  • mzucchetto
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mzucchetto replied the topic: RNAV Minima

Hey Bob

Thanks for the quick reply, I was hoping i hadn't missed anything previously in the text.

Cheers
Mark
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