P-rnav question
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From: Here and there
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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From: UK
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?
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?

Joined: Mar 2004
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From: Japan / Thailand
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.
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.
Per Ardua ad Astraeus
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From: UK
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From: Uh... Where was I?
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.
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.

Joined: Nov 1999
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From: Oz
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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From: PuB near U
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 ?
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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From: West
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.
"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.
Per Ardua ad Astraeus
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From: UK
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?
"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?
Joined: Nov 2005
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From: LAV A
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 March 2011 at 16:44.
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From: engineer at large
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.

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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From: engineer at large
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
http://www2.icao.int/en/pbn/ICAO%20D...Operations.pdf

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