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P-rnav question

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P-rnav question

Old 13th Mar 2011, 15:09
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P-rnav question

If a STAR is described as being p-rnav(gnss) and your aircraft is not fitted with gps can you legally fly it if the best capability of your aircraft is IRS/DME/DME?
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Old 13th Mar 2011, 15:31
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You can be P-RNAV approved without GPS, so DME/DME/IRS should be enough. But you need to check your documentation.
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Old 13th Mar 2011, 15:41
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Hi tubby linton,

I'd say no you can't because you don't have the equipment specified on the chart. Some charts show (DME/DME; GNSS) in which case you could.

Maybe there isn't good enough DME coverage? Which airport is it?
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Old 13th Mar 2011, 16:02
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Generally, DME/DME/IRS will meet the requirements for P-RNAV, but you would have to check your aircraft manual to be sure.

If you use DME/DME/IRS and the failure of a DME would affect the service coverage, then there will be a published Critical DME Gap on the chart. Your aircraft's equipment will determine how big that gap can be and still maintain the required RNP.

After a second read of your post, I would clarify my above statement. If the chart says (GNSS) then I would say that you must have a GPS and DME/DME/IRS would not permit you to fly the STAR.
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Old 13th Mar 2011, 16:08
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If the chart specifies "gnss", then that equipment is mandatory.
So without GPS, it will not be acceptable....
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Old 13th Mar 2011, 16:11
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www.ecacnav.com/downloads/BO5RNPRNAP02.pdf
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Old 13th Mar 2011, 16:12
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The airport is GVA and the star particularly says GNSS on it- the Lusar arrival.As far as I can remember this arrival use to be a plain rnav arrival but it has obviously changed.
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Old 13th Mar 2011, 18:21
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If the plate is GNSS, you need a GPS.

I understand in the case of an approach, where the geometry of DME/DME position makes precision or even availability difficult.

In a STAR, however, it is difficult that you are not within coverage of several DMEs with good geometry.
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Old 13th Mar 2011, 23:20
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The ports that I fly to that have P-RNAV departures and arrivals also have alternative charts for those aircraft unable to use P-RNAV procedures (be it because of the lack of equipment or unserviceabilities). If there is no alternative chart, then you must request an alternative clearance, which will most likely be radar vectors.
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Old 14th Mar 2011, 01:39
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This is a very interesting question....i'm always very confused by this prnav gnss ...

Can someone post some good examples of airports dep /arr for this plz?

Need to learn more.

what must the ops spec be for prnav approved? rnav 1 or rnp1 ?
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Old 14th Mar 2011, 14:38
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Do any of those of you who fly p-rnav procedures have an aide memoire,or quick reference card to cover this kind of operation or is it included in your sop?
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Old 14th Mar 2011, 15:31
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P-RNAV can be certified without GNSS

I encourage all to find source documents for questions like this. Some of the info posted by others are not accurate. Even the link I include on this post is very general in nature. Instead, your regulatory agency and company Ops Specs are better sources.

"P-RNAV capability can be achieved using inputs from DME/DME or GNSS.
Many existing aircraft can achieve P-RNAV capability without additional onboard equipment."

http://www.ecacnav.com/downloads/P-R...20notices).pdf

As Perfomance Based Navigation continues deployment in Europe and around the globe, you will see additional equipment requirements. Perhaps it is of interest to you that PBN requires certification of avionics, pilots, and pilot training programs.
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Old 14th Mar 2011, 16:38
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Not forgetting, of course, that the original question was:

"If a STAR is described as being p-rnav(gnss) and your aircraft is not fitted with gps can you legally fly it if the best capability of your aircraft is IRS/DME/DME?
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Old 14th Mar 2011, 16:55
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If the procedure is P-RNAV(GNSS) then you will need a serviceable GPS. If DME/DME/IRS updating is acceptable for a different P-RNAV procedure then the plate will say so.

Last edited by mike501; 20th Mar 2011 at 17:44.
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Old 14th Mar 2011, 18:54
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I with None on this one...there is far too much disinformation here.....

One could go on for pages on requirements, BUT...

As for documentation: The only source you should use is your respective OpsSpec. This and only this, will give all of the particular guidance, as there can be waivers, exemptions, and such. You may only have the spec for .3 RNP, even though the charts and FMS equipment show .1 RNP is available...
and the equipage requirements build upon each other, so its not if/then...its if/if/then/if/and only if/then

I will add this quickly on charts, RNP in particular.

The chart shows Glide Path Angle, the default criteria design is 3 degrees..
The chart will note if this is not ILS coincident.
RNP designs are currently uncompensated baro based for vertical. The low temperature limits shown on the charts is where the design GPA of 3 degrees hits 2.71 degrees...

The original question noted P-RNAV(GNSS) ...you need GPS to use this, currently, the governing bodies require at least 2 operational GPS to use a procedure.

For Oceanic RNP-10, I believe only one GPS unit is required, and your inertial drift time must be able to keep it in this bound.
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Old 14th Mar 2011, 19:03
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I recommend ICAOs PBN manual
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Old 14th Mar 2011, 19:09
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This AC sets out a series of performance and functional criteria necessary to conduct RNAV procedures.

http://www2.icao.int/en/pbn/ICAO%20D...Operations.pdf
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Old 14th Mar 2011, 19:46
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FAA link to ICAO PBN manual

ICAO PBN manual
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Old 15th Mar 2011, 20:35
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Upper air,thank you for the link to the guide.My first post incorrectly labelled the STARas p-rnav ,it is actually rnav(gnss)
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