Rnav1 (gnss)
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Rnav1 (gnss)
Hi
How is one supposed to comprehend the following statement which is sometimes mentioned on the approach charts:
" PROCEDURE FOR RNAV1 (GNSS) ACFT "
Does it mean that this procedure is for:
a) RNAV1 Aircraft which must have a GPS input; or
b) RNAV1 Aircraft (regardless of GPS input) OR Aircraft which has a GPS
Thankyou
How is one supposed to comprehend the following statement which is sometimes mentioned on the approach charts:
" PROCEDURE FOR RNAV1 (GNSS) ACFT "
Does it mean that this procedure is for:
a) RNAV1 Aircraft which must have a GPS input; or
b) RNAV1 Aircraft (regardless of GPS input) OR Aircraft which has a GPS
Thankyou
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Neither. It means an aircraft meeting RNAV1 and has an appropriate GPS (or GLONASS or Galileo). This would be standard for European RNAV1 operations and could fly any RNAV1 route, departure or approach.
Under the FAA, an aircraft can meet RNAV1 without a GPS. This could then fly RNAV1 routes and RNAV1 DME/DME/IRU departures and approaches (which are constrained by ground navaid placement and availability). This plane could not fly an RNAV1 (GNSS) approach.
Under the FAA, an aircraft can meet RNAV1 without a GPS. This could then fly RNAV1 routes and RNAV1 DME/DME/IRU departures and approaches (which are constrained by ground navaid placement and availability). This plane could not fly an RNAV1 (GNSS) approach.
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Catia,
This is not correct, there is no need for GNSS to meet RNAV-1, infact if you look at a LIDO chart it is endorsed by the ANSP as "RNAV-1, DME/DME,IRU or GNSS required"
You should also note that RNAV-1 and European P-RNAV are although similar not the same thing.
PT6A
P-RNAV is a European Navigation Standard, which equates to a track keeping accuracy of +/-1nm on SIDs, STARs and Initial Approaches for 95% of flight time. It requires the procedures to be coded into a navigation database and used without modification by the flight crew, other than ‘direct to' ATC clearances. It also includes the need for ‘fly-by' and ‘fly-over' waypoints. Whilst the procedures are designed to a +/- 1nm tolerance, track keeping is based on air navigation service provider assessment of the available navigation aids against the minimum airborne equipment standard. There is no requirement for RNP alerting functions within the FMS and track keeping can be assumed to be met on the condition that airborne equipment and radio updating are functioning correctly, the aircraft is being flown with Autopilot or Flight Director and navigation cross check has been completed at the start of the procedure as defined in the aircraft operations manual. P-RNAV approval covers SIDs and arrival procedures only to the Final Approach Fix (FAF). P-RNAV was primarily intended to be a Terminal Area navigation specification, however some European air navigation service providers are also intending to specify use of P-RNAV in the continental en-route structure to provide greater capacity with closer route spacing. P-RNAV will not be a navigation specification in the PBN since it allows the use of DME/VOR updating which the equivalent RNAV1 in the PBN manual does not. Furthermore for RNAV1 SID's there is a requirement for RNAV guidance no later than 500 ft above airfield elevation which some current P-RNAV approved aircraft do not meet.
This is not correct, there is no need for GNSS to meet RNAV-1, infact if you look at a LIDO chart it is endorsed by the ANSP as "RNAV-1, DME/DME,IRU or GNSS required"
You should also note that RNAV-1 and European P-RNAV are although similar not the same thing.
PT6A
P-RNAV is a European Navigation Standard, which equates to a track keeping accuracy of +/-1nm on SIDs, STARs and Initial Approaches for 95% of flight time. It requires the procedures to be coded into a navigation database and used without modification by the flight crew, other than ‘direct to' ATC clearances. It also includes the need for ‘fly-by' and ‘fly-over' waypoints. Whilst the procedures are designed to a +/- 1nm tolerance, track keeping is based on air navigation service provider assessment of the available navigation aids against the minimum airborne equipment standard. There is no requirement for RNP alerting functions within the FMS and track keeping can be assumed to be met on the condition that airborne equipment and radio updating are functioning correctly, the aircraft is being flown with Autopilot or Flight Director and navigation cross check has been completed at the start of the procedure as defined in the aircraft operations manual. P-RNAV approval covers SIDs and arrival procedures only to the Final Approach Fix (FAF). P-RNAV was primarily intended to be a Terminal Area navigation specification, however some European air navigation service providers are also intending to specify use of P-RNAV in the continental en-route structure to provide greater capacity with closer route spacing. P-RNAV will not be a navigation specification in the PBN since it allows the use of DME/VOR updating which the equivalent RNAV1 in the PBN manual does not. Furthermore for RNAV1 SID's there is a requirement for RNAV guidance no later than 500 ft above airfield elevation which some current P-RNAV approved aircraft do not meet.
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PT6A,
I'm not sure where I'm wrong. I said you don't need a GPS to fly RNAV1 DME/DME/IRU approach but you do need a GPS for a RNAV1 GNSS approach.
Does RNAV1 (GNSS) even exist as a specification in Europe?
I'm not sure where I'm wrong. I said you don't need a GPS to fly RNAV1 DME/DME/IRU approach but you do need a GPS for a RNAV1 GNSS approach.
Does RNAV1 (GNSS) even exist as a specification in Europe?
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There is no such thing as RNAV-1 (GNSS) just that a GNSS can be used as one way to be RNAV-1 approved.
Europe uses P-RNAV, there maybe some ANSP's using RNAV-1 as the standard, the main difference being that RNAV-1 requires the aircraft to follow guidence from 500ft, P-RNAV does not.
Neither standard requires the use of GPS at all, however, many aircraft use their GPS/GNSS as a means of compliance with the relevant standard.
With regard to the OP could he tell us for which airport he is refering, as some ANSP's do levvy a few of their own requirements depending on if the method of RNAV-1 compliance is GNSS based.
Eg. Many of the US airports require RADAR if the method of RNAV-1 compliance is not GNSS - even though the ICAO standard does not.
PT6A
Europe uses P-RNAV, there maybe some ANSP's using RNAV-1 as the standard, the main difference being that RNAV-1 requires the aircraft to follow guidence from 500ft, P-RNAV does not.
Neither standard requires the use of GPS at all, however, many aircraft use their GPS/GNSS as a means of compliance with the relevant standard.
With regard to the OP could he tell us for which airport he is refering, as some ANSP's do levvy a few of their own requirements depending on if the method of RNAV-1 compliance is GNSS based.
Eg. Many of the US airports require RADAR if the method of RNAV-1 compliance is not GNSS - even though the ICAO standard does not.
PT6A
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examples
Hi, Thanx for the input.
Click on the following links to see some examples that might help to explain my query.
1) Abu Dhabi STAR - 10-2
http://64.176.58.144/omaa10-2.pdf
2) Abu Dhabi STAR - 10-2H
http://64.176.58.144/omaa10-2H.pdf
Above mentioned chart 10-2 says RNAV 1 (GNSS) and 10-2H says RNAV 5.
It gives an impression that even if your A/C is RNAV1 certified, you still need to have a GPS input to your RNAV system in order to fly the approach of 10-2 otherwise you go for RNAV 5 procedure mentioned in 10-2H.
See this now:
3) Frankfurt STAR - 10-2
http://64.176.58.144/eddf10-2.pdf
4) Frankfurt STAR - 10-2E
http://64.176.58.144/eddf10-2E.pdf
10-2 for Frankfurt says:
"Procedures should be used ... by all RNAV (GPS) equipped a/c"
whereas 10-2E says:
"RNAV Transitions for GPS or FMS Equipped A/C"
Instructions in 10-2E are more precise and clear giving an indication that RNAV (GNSS) does not necessarily mean that GPS is required to an other wise sound RNAV system.
Please correct me if I am wrong, according to my understanding GPS input is not necessary for P-RNAV certification or for an aircraft to fly an RNAV 1 procedure. However a local area procedure can make it necessary.
There is no ambiguity if the statement is like "RNAV 1, GPS REQUIRED, RADAR REQUIRED" as mentioned in Catia's example.
But regarding the examples I have given, I am just interested to know if there is some standard phraseology and interpretation about this issue which I have addressed.
Thanks for your time.
Click on the following links to see some examples that might help to explain my query.
1) Abu Dhabi STAR - 10-2
http://64.176.58.144/omaa10-2.pdf
2) Abu Dhabi STAR - 10-2H
http://64.176.58.144/omaa10-2H.pdf
Above mentioned chart 10-2 says RNAV 1 (GNSS) and 10-2H says RNAV 5.
It gives an impression that even if your A/C is RNAV1 certified, you still need to have a GPS input to your RNAV system in order to fly the approach of 10-2 otherwise you go for RNAV 5 procedure mentioned in 10-2H.
See this now:
3) Frankfurt STAR - 10-2
http://64.176.58.144/eddf10-2.pdf
4) Frankfurt STAR - 10-2E
http://64.176.58.144/eddf10-2E.pdf
10-2 for Frankfurt says:
"Procedures should be used ... by all RNAV (GPS) equipped a/c"
whereas 10-2E says:
"RNAV Transitions for GPS or FMS Equipped A/C"
Instructions in 10-2E are more precise and clear giving an indication that RNAV (GNSS) does not necessarily mean that GPS is required to an other wise sound RNAV system.
Please correct me if I am wrong, according to my understanding GPS input is not necessary for P-RNAV certification or for an aircraft to fly an RNAV 1 procedure. However a local area procedure can make it necessary.
There is no ambiguity if the statement is like "RNAV 1, GPS REQUIRED, RADAR REQUIRED" as mentioned in Catia's example.
But regarding the examples I have given, I am just interested to know if there is some standard phraseology and interpretation about this issue which I have addressed.
Thanks for your time.
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Even the GPS REQUIRED notation might be ambiguous depending on your aircraft documentation.
For example the generic boeing 737 FCOM tells us the following about GPS approaches:
GPS approach - an approach designed for use by airplanes using stand-alone GPS receivers as the primary means of navigation guidance. However Boeing airplanes using FMS as the primary means of navigation guidance, have been approved by the FAA to fly GPS approaches provided an TNP of 0.3 or smaller is used.
Since that is achievable without GPS updating this excerpt actually allows us to fly GPS approaches without having a GPS, for example in 737 classics without GPS retrofit.
Granted, that is only for approaches and not arrival procedures. however as you correctly say GPS is not required for P-RNAV certification, no clue about RNAV 1 though.
For example the generic boeing 737 FCOM tells us the following about GPS approaches:
GPS approach - an approach designed for use by airplanes using stand-alone GPS receivers as the primary means of navigation guidance. However Boeing airplanes using FMS as the primary means of navigation guidance, have been approved by the FAA to fly GPS approaches provided an TNP of 0.3 or smaller is used.
Since that is achievable without GPS updating this excerpt actually allows us to fly GPS approaches without having a GPS, for example in 737 classics without GPS retrofit.
Granted, that is only for approaches and not arrival procedures. however as you correctly say GPS is not required for P-RNAV certification, no clue about RNAV 1 though.
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RNAV 1 is one thing. But sometimes it is not enogh with RNAV 1. They also require GNSS. Meaning that IRS/DME/DME is not acceptable even if you have RNAV 1 approval.
The Abu Dhabi procedures are RNAV GNSS: GPS required (still no galileo available)
the Frankfurt procedures:
10-2 is same as Abu Dhabi, GPS required.
transitions: either GPS or FMS required
The Abu Dhabi procedures are RNAV GNSS: GPS required (still no galileo available)
the Frankfurt procedures:
10-2 is same as Abu Dhabi, GPS required.
transitions: either GPS or FMS required
Last edited by Microburst2002; 21st Jun 2011 at 17:14.
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RNAV 1 can be predicated on GNSS and/or DMEDME. This specific example is given in the ICAO PBN manual. Each state can choose their own specification and in this case UAE require the use of GNSS. AS the same regulations do not apply in all states there will continue to be these problems. ICAO failed to fix it with the RNP regulations and have failed again with PBN.
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approved by the FAA to fly GPS approaches provided an TNP of 0.3 or smaller is used.
Depending on your navdatabase provider, you may not be able to select some of these waypoints if you are not capable.
Much of the terminology is in transition, so you will see a multitude of phrases that CAN mean the same thing, or may not. Unless you specifically see "GPS required", AR, SAAR, there are many ways to achieve RNAV-1.
ie RNAV (GPS) is not the same as RNAV 1 (GPS)...
(and of course, the local agency may have driven the terminology, or I find many mistakes on plates as well...)
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Thankyou everyone for all the inputs:
Thats where the confusion begins 
Frankfurt 10-2E is an RNAV Transition e.g. KERAX25N for Rwy 25R involves about 17 waypoints. As compared to a STAR it involves more precision, especially as compared to 10-2 RNAV STAR KERAX1G for Rwy 25R which involves just 1 way point and 2 VORs.
I cant technically understand that in the same area 10-2E (which is much more complex than 10-2) can be flown with either FMS or GPS whereas 10-2 (which involves only 1 waypoint) requires a GPS input to make RNAV status more reliable.
So when its written RNAV (GNSS) then does it mean that GPS input is mandatory?
It seems "Yes" if u look at AbuDhabi charts and looks like "No" if u look at Frankfurt charts
I think its more of a language problem than technical
I understand that requirement can be different in different regions, my query is really about the way its written i.e. RNAV (GNSS). Does it mean the same everywhere or its interpretation is also different in different regions.
the Frankfurt procedures:
10-2 is same as Abu Dhabi, GPS required.
transitions: either GPS or FMS required
10-2 is same as Abu Dhabi, GPS required.
transitions: either GPS or FMS required
Frankfurt 10-2E is an RNAV Transition e.g. KERAX25N for Rwy 25R involves about 17 waypoints. As compared to a STAR it involves more precision, especially as compared to 10-2 RNAV STAR KERAX1G for Rwy 25R which involves just 1 way point and 2 VORs.
I cant technically understand that in the same area 10-2E (which is much more complex than 10-2) can be flown with either FMS or GPS whereas 10-2 (which involves only 1 waypoint) requires a GPS input to make RNAV status more reliable.
So when its written RNAV (GNSS) then does it mean that GPS input is mandatory?
It seems "Yes" if u look at AbuDhabi charts and looks like "No" if u look at Frankfurt charts
I think its more of a language problem than technical
I understand that requirement can be different in different regions, my query is really about the way its written i.e. RNAV (GNSS). Does it mean the same everywhere or its interpretation is also different in different regions.
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So when its written RNAV (GNSS) then does it mean that GPS input is mandatory?
Regarding the "complexity" of the transition: it is just a "transition", rather than a STAR (regardless of the number of waypoints) so requirements can be more "relaxed", I guess, so it is enough if you have a GPS with RNAV capability or an FMS.
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Haroon
Frankfurt is EU and the procedures are P-RNAV.
This is similar but not the same as RNP 1.
The use of GNSS depends on the A/C type. If your AFM says you must have GNSS to meet P-RNAV then you must have it. If it doesn't then you don't. Some aircraft meet P-RNAV requirements by fitting a standalone GPS system. For these aircraft the use of GPS is mandatory.
These regs can all be found here: EUROCONTROL Navigation Domain - What is P-RNAV?
The UAE plates are PBN compliant and info can be found here: PERFORMANCE BASED NAVIGATION TRAINING PACKAGE Version 2.0
This is similar but not the same as RNP 1.
The use of GNSS depends on the A/C type. If your AFM says you must have GNSS to meet P-RNAV then you must have it. If it doesn't then you don't. Some aircraft meet P-RNAV requirements by fitting a standalone GPS system. For these aircraft the use of GPS is mandatory.
These regs can all be found here: EUROCONTROL Navigation Domain - What is P-RNAV?
The UAE plates are PBN compliant and info can be found here: PERFORMANCE BASED NAVIGATION TRAINING PACKAGE Version 2.0
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Thanks Hoppy for the links. PBN was new to me. After going through the PBN presentation I think I got your point.
However if you come across a procedure at an Airport XYZ which says RNAV (GNSS), then how does one figure out whether it is PBN or P-RNAV compliant?
Thanks everyone
However if you come across a procedure at an Airport XYZ which says RNAV (GNSS), then how does one figure out whether it is PBN or P-RNAV compliant?
Thanks everyone