Flying low a high for Qantas

[Wirraway]

Thurs "The Australian"

Flying low a high for Qantas
Steve Creedy, Aviation writer
January 13, 2005

NEW navigation procedures adopted by Qantas are giving the flying kangaroo an edge over its rivals to one of the trans-Tasman's most popular destinations.

Airline officials say the greater flexibility of the new procedures allows the airline to better guarantee an arrival to the ski destination of Queenstown and to do it more safely.

Qantas is only the third airline in the world, and the only one outside North America, to use the procedures, known as Required Navigation Performance.

The technology uses on-board global positioning system and inertial navigation equipment to accurately pinpoint the aircraft's position to within 37m.

It allows the design of safer routes to mountainous destinations, such as New Zealand's Queenstown, and lowers the threshold at which the pilot must be able see the ground for a visual approach.

The system is coupled to the auto-flight system and reduces reliance on ground-based navigation aids.

Qantas expects its visual threshold this year will be 1500ft lower than its competitors, who must be at 2700ft to fly visually. It will progressively step down to a design minimum of 250ft.

"If you go to Queenstown, that's what will happen next winter," said Qantas chief pilot Chris Manning.

"Unless it's fog, we will be able to guarantee, in most conditions, an arrival into Queenstown."

Other advantages of the new system include an increased payload and reduced engine wear.

Qantas intends to introduce it to Australian destinations such as Canberra and on its "Silk Route" over China.

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[Tagneah]

Qantas is only the third airline in the world, and the only one outside North America, to use the procedures, known as Required Navigation Performance.

Nice research Mr Creedy (again)

DJ are doing RNAV GNSS approaches too now, just not into Queenstown (yet)

Tag

[Capt Fathom]

I think you will find there is a difference between GPSNPA approaches, and GPS approaches using RNP.

RNP can also be used for departure.
Alaskan Airlines use RNP0.15 / RNP0.3 for their operations into Juneau, Alaska.

Juneau (http://www.boeing.com/commercial/aeromagazine/aero_12/navigation_alaska.html)

[neville_nobody]

Insert Foot here :E

GPS approaches and RNP are two different things. RNP can involve making turns during the approach, and give you vertical profile same as a ILS.

GPS approaches are only giving you a position left or right of the centreline. The same could be done with a FMC but with no vertical NAV. RNP actually gives a glide path

Where are DJ doing these approaches as there is nowhere in Australia that would require it except for possibly Mt Hotham.

For more info Check out

http://www.aviationnow.com/avnow/news/channel_comm.jsp?view=story&id=news/aw070845.xml

http://www.washingtonpost.com/ac2/wp-dyn/A54830-2002Sep8?language=printer

There are a few technical articles I've read over the last few years on this but none posted on the web

[Capn Bloggs]

Nev,
Where are DJ doing these approaches as there is nowhere in Australia that would require it except for possibly Mt Hotham.
There are plenty of places where this type of approach could be used in Oz: try all the GPS NPAs that aren't aligned with the runway, for a start, and all those that have vertical limits that are very close to or on the standard 3° glidepath, which are difficult to manually fly.

[neville_nobody]

This type of technology COULD be used everywhere. But it isn't REQUIRED due to terrain as it is in Alaska, PNG etc etc. Those places need a curved approach to dodge mountains. And where are DJ doing these approaches at the moment??

Having RNP's at major airports in Australia is only out of convience rather than necessity. By the sounds of it though it could be everywhere within 10 years.

[Tagneah]

The technology uses on-board global positioning system and inertial navigation equipment to accurately pinpoint the aircraft's position to within 37m.

So QF are using GPS (now called GNSS) to reduce the Aircraft's ANP to the RNP that the approach requires.

By manualy inserting 0.15 into the RNP field the aircraft will alert the crew if the ANP exceeds the set value. By inhibiting DME updating the aircraft then uses GPS for updates so that any loss of signal will cause the ANP to increase.

The fact is DJ NG's are using the same technology as QF NG's. QF are not the only airline outside North America use it.

I dont think there is such a thing as an RNP approach but rather an approach (GNSS or VOR etc) that has a RNP value that the aircraft has to achieve.

Tag

[Capt_SNAFU]

Tagneah

Sorry but you are incorrect, although the technology on the aircraft is the same. The QF approaches into Queenstown are completely different to the type used for a standard GNSS approach in Aus. Curved approaches (as neville stated) with differing minimas (200' HAT type minimas) based on ANP are what is being trialled into Qtown at the present also departures are in the works.

QF are infact the third airline in the world to use these procedures, as initialy stated.

There are plenty of places in Aus were lower approach minimas or curved approaches could be used. E.g TSV.

Where did DJ get it's GPS training package from?????

[Capn Bloggs]

From a PC, no less! ;)