RNP SID with RF leg

[FlightPathOBN]

I understand, but that is what were were told by the FAA, it must have been just for the custom RNP AR...

[9.G]

OK FPO, regardless of you fallouts the topic needs clarifications. First of all, airbus allows to fly DME ARC with unserviceable NAV AID, which essentially is nothing but a radius to reference point. VOR DME is stored as a reference point in our data base that's why we need to check NAV accuracy in TMA and if not satisfactory revert to raw data. No such option is available for RNP and that's the only difference. As stated before contingency is what's relevant for this type of approach. From technical and geometrical point of view however there's no difference at all. The question is however related to SID. I recommend you to read 17th airbus safety conference brochure S RNP-AR publication in which there's a table classifying what's AR and what's not. DEP and/or missed approach RNP < 1 NM is AR. 1 NM is NOT AR. You gotta give the befit of the doubt and maybe some credit to others.

[FlightPathOBN]

please provide a link to the reference document you are talking about.

From doc 9905 RNP procedure design manual

2.1.1 RNP APCH versus RNP AR APCH
2.1.1.1 RNP APCH is defined as an RNP approach procedure that requires a lateral TSE of +/-1 NM in the initial, intermediate and missed approach segments and a lateral TSE of +/- 0.3 NM in thefinal approach segment. Guidance on implementing RNP APCH operations can be found in the PBN
Manual, Volume II, Chapter 5, Implementing RNP APCH.
2.1.1.2 RNP AR APCH is defined as an RNP approach procedure that requires a lateral TSE as low as +/- 0.1 NM on any segment of the approach procedure. RNP AR APCH procedures also require that a specific vertical accuracy be maintained as detailed in the PBN Manual, Volume II, Chapter 6.

[aterpster]

9.G:

No such option is available for RNP and that's the only difference.

For the avionics engineer the coding is different for an RF leg than a DME ARC.

This is significant to the crew in the respect that the crew has no idea where the center point of an RF leg is, unlike a DME ARC.

Another significant difference between RNP AR and all other forms of RNAV procedures is that, in accordance with the table FPO posted, an RNP AR IAP does not have to taper down as it progresses towards the runway. Segment widths can decrease, then increase, then decrease, except no segment can be of a lesser RNP value than the final segment, and the final segment cannot vary in width in a given IAP. Also, there is no secondary area obstacle protection, unlike all other instrument procedures.

[FlightPathOBN]

sounds good terpster,

I would also add that currently, the public RNP design criteria does not address DEP. It will be included in 8260.PBN, whenever that may happen...RNP 1 DP Specials


other RNP 1 reference....
RNP 1 AC90-105

(1) Pilots must not fly an RNP 1 procedure unless it is retrievable by the procedure name from the onboard navigation database and conforms to the charted procedure. Numeric values for courses and tracks should be automatically loaded from the RNP navigation database for required leg types. However, the procedure may subsequently be modified through the insertion or deletion of specific waypoints in response to ATC clearances. The manual entry or creation of new waypoints, by manual entry of latitude and longitude or rho/theta values is not permitted.
Additionally, pilots must not change any database waypoint type from a fly-by to a fly-over or vice versa.
(2) The pilot must confirm the correct procedure is selected. This process includes confirmation of the waypoint sequence, reasonableness of track angles and distances, and any other parameters that can be altered by the pilot, such as altitude or speed constraints. A navigation system textual display or navigation map display must be used.
(3) For RNP 1 procedures, pilots must use a lateral deviation indicator, flight director, or autopilot in lateral navigation (LNAV) mode. Pilots of aircraft with a lateral deviation display must ensure lateral deviation scaling is suitable for the navigation accuracy associated with the procedure.

Functional Requirements.
(1) Autopilot and Flight Director. RNP procedures with RF legs require the use of an autopilot or flight director with at least “roll-steering” capability that is driven by the RNP system. The autopilot/flight director must operate with suitable accuracy to track the lateral and, as appropriate vertical paths required by a specific RNP procedure.
(2) The aircraft must have an electronic map display depicting the RNP computed path of the selected procedure.
(3) The flight management computer, the flight director system, and the autopilot must be capable of commanding a bank angle up to 25 degrees above 400 feet AGL.
(4) Maintaining LNAV in missed approach. If abandoning a procedure while on an RF Leg or initiating a go-around or missed approach (through activation of TOGA or other means), the flight guidance mode should remain in LNAV to enable display of deviation and display of positive course guidance during an RF leg. If the aircraft does not provide this capability, crew procedures must be used that assure the aircraft will adhere to the specified flight path during the RF Leg segment.
NOTE: For missed approaches with a RF Leg, the flightcrew must be able to couple the autopilot or flight director to the RNP system (engage LNAV) by 500 feet AGL.

[FlightPathOBN]

The flavor of the regs makes the assumption that the procedure may have been changed in the aircraft database by another pilot.

There are 2 main reasons why there all of the verbiage on verification of what is on the plate, concurs with what is in the FMC.
Verification that what shows up in the FMC is what is shown on the plate, and;
for you to make verify that your aircraft has the ability to perform the procedure.

In the case of the HK departure, the procedure mandates 5000 feet at 5nm from runway end, basically 1000 feet/nm climb rate. If your aircraft cannot make that, YOU must assume the procedure is NA.
It is up to the pilot, even if the procedure is in the FMC to select, if with conditions, the ac cannot comply.

Throughout my numerous posts on this site, I have been extremely vocal about adding any waypoint data, this is why.
One may accidentally overwrite a waypoint used in another procedure without even knowing it.
When you or another operator enters the other procedure, you may or may not realize the error, especially waypoints that are not part of a distinct RNP procedure.
Once the navdatabase has been uploaded on to the ac, there is NO error checking other than the AIRAC cycle.

[9.G]

FPO, I tried copying it but for it doesn't work here but if someone can copy paste that table I'd appreciate it.

This is significant to the crew in the respect that the crew has no idea where the center point of an RF leg is, unlike a DME ARC.

and how am I supposed to know that with DME being U/S? That's the whole point here. It might be depicted on the chart but if it's U/S there's no way to confirm it with raw data but as long as GPS is primary, accuracy based on a/c FMS calculation algorithm, is sufficient. DME ARC as RF is flown outta DB. The coding might be different but from operational point of view there's no difference whether I'm flying a RF leg or DME ARC without DME indication.

Another significant difference between RNP AR and all other forms of RNAV procedures is that, in accordance with the table FPO posted, an RNP AR IAP does not have to taper down as it progresses towards the runway. Segment widths can decrease, then increase, then decrease, except no segment can be of a lesser RNP value than the final segment, and the final segment cannot vary in width in a given IAP. Also, there is no secondary area obstacle protection, unlike all other instrument procedures.

That's all covered by the operational approval. I don't need to immerse into technicalities as I like to KISS. Keep it simple and short. Approval is enough grounds to make a decision.

[jorgesvrider]

If the aircraft is rnav1 sids stars aproved and is capable of rf legs you can fly all the procedures rnav 1 except those listed as "ar"authorization requiered but that only means that the crew requires special training for that specific chart, and when the airline give that training is just for that specific procedure not for all the "ar"procedures.
Just like the aproaches if you are rnp0.3 you can fly
all the rnp aproaches ( rnav gps "gnss" ) but you cannot fly
the rnp ar aproaches ( rnav rnp ) unless you get the special
trainning and aproval .

[9.G]

link

s Rnp Rnp Ar Approaches it's on the page 9.

[FlightPathOBN]

You are taking this table out of context.
For this presentation they are referencing Approach and Missed Approach.

The lack of a check, does not mean it is not considered AR at RNP 1.

Rather than a powerpoint, I would suggest the criteria, and design criteria.

[9.G]

FPO, how bout this one then

SECTION 2. AREA NAVIGATION (RNAV) AND REQUIRED NAVIGATION PERFORMANCE (RNP)
1. RNP Levels. An RNP “level” or “type” is applicable to a selected airspace, route, or procedure. As defined in the Pilot/Controller Glossary, the RNP Level or Type is a value typically expressed as a distance in nautical miles from the intended centerline of a procedure, route, or path. RNP applications also account for potential errors at some multiple of RNP level (e.g., twice the RNP level).
(a) Standard RNP Levels. U.S. standard values supporting typical RNP airspace are as specified in TBL 1-2-1 below. Other RNP levels as identified by ICAO, other states and the FAA may also be used.
TABLE 1-2-1 U.S. Standard RNP Levels

RNP Level
Typical Application
Primary Route Width (NM) - Centerline to Boundary
0.1 to 1.0
RNP SAAAR Approach Segments
0.1 to 1.0
0.3 to 1.0
RNP Approach Segments
0.3 to 1.0
1
Terminal and En Route
1.0
2
En Route
2.0
NOTE:
1. The“performance”ofnavigationinRNPrefersnotonlytothelevelofac curacyofaparticularsensororaircraftnavigation system, but also to the degree of precision with which the aircraft will be flown.
2. Specific required flight procedures may vary for different RNP levels.

(b) Application of Standard RNP Levels. U.S. standard levels of RNP typically used for various routes and procedures supporting RNAV operations may be based on use of a specific nav- igational system or sensor such as GPS, or on multi-sensor RNAV systems having suitable performance.
(c) Depiction of Standard RNP Levels. The applicable RNP level will be depicted on affected charts and procedures.

You can find it in Jeppeen Radio data general p 225. It's official source. You're one stubborn son of gun.

[FlightPathOBN]

The procedures that you see in that presentation, I have designed, provided the obstacle and flight validation, as well as trained the crew in SIM and flight val.

There is always one in the class that just doesnt get it.

[9.G]

Hang on a sec FPO, let me just get it straight here. I can live with the idea of me being a slow grasping pupil. I find it however highly improbable that all the other reputable organisations like Airbus, Jeppesen and last but not least wikipedia Required navigation performance - Wikipedia, the free encyclopedia concept description all got it wrong. Come on mate, be reasonable. It's far more simpler than you're trying to picture it. It's black on white: when AUTHORIZATION IS REQUIRED it's clearly depicted on the chart. The comparison

RNP approaches include capabilities that require special aircraft and aircrew authorization similar to category II/III ILS operations.

is the best way to understand SAAAR or AR. While operator must be approved for LVO no authorization is required for LVO take off unlike approach. That's why HKG ATC section speaks only bout the approach. That's why there's nothing mentioned about AR on the departure plate. It's really been fun.

[aterpster]

9.G:

I find it however highly improbable that all the other reputable organisations like Airbus, Jeppesen and last but not least wikipedia Required navigation performance - Wikipedia, the free encyclopedia concept description all got it wrong.

Wikipedia did get one item wrong, or at least incomplete, and I quote:

When conducting an RNP SAAAR approach with a missed approach less than RNP 1.0, no single-point-of-failure can cause the loss of guidance compliant with the RNP value associated with a missed approach procedure. Typically, the aircraft must have at least dual GNSS sensors, dual flight management systems, dual air data systems, dual autopilots, and a single inertial reference unit.

At least one IRU is also required when any part of the approach phase requires RNP of less than 0.30, even though the missed approach may not require RNP of less than 1.0.

From a pilot perspective RNP AR is easy, as are operational concepts and actual flying of the procedures.

What is not easy are the hoops the airframe OEM has to jump through to qualify the aircraft, what the operator of an RNP AR aircraft has to do to validate the database and its performance in any qualified airframe's FMSes, and the design and flight inspection requirements.

There are so many different FMSes out there with so many variables in software, it is mandatory that the additional database and performance validation steps must be taken to assure performance on the often far less forgiving RNP AR approach procedures.

[9.G]

I gotcha aterpster and no objections there. Nobody said obtaining the approval will be a walk in the park. However that's not the point here. Again that's what's it all bout :

My company is a RNP-AR certified operator. The pilots are trained (or will be) for RNP-AR ops. Other aircraft in our fleet have full RNP-AR certification but the A340-300 is not and Airbus doesn't seem too interested in certifying it for RNP-AR ops. The A340-300 can however legally fly RNP 1 SID's and can fly RF Legs.

We will have to get our Nav DB vendor to code these procedures before we use them so there will be no manual insertion into the FMS nonsense.

Can the A340-300 with Honeywell FMS 2 legally fly this procedure if it is in the aircraft's Nav DB?

It's a plain language question with all the prerequisites given. Let's see:
HKG published new SIDs with RNP1 and RF for noise mitigation purposes. The requirements for those SIDs are published and clearly written on the plate and AIP. The operator is approved for RNP 1 as per OPS SPECS. SID is in the DB as published. BTW no approval will be granted by the state of a/c registry unless vendor's DB has been demonstrated to be satisfactory. OpSpec/MSpec/LOA C063, Area Navigation (RNAV) and Required Navigation Performance (RNP) Terminal Operations is an example of OPS SPECS approval. Provided the aircraft is airworthy there's absolutely nothing precluding DH from flying this SID. All this fuss about SAAAR or AR APPROACHES is completely irrelevant to this issue. DH isn't interested in academical particularities of design criteria. He's an operator like me and sitting in the cockpit before departure my only concern is CAN or CAN'T I fly it? Again no need to mastrubate his brain.
I'm done here.

[BOAC]

Again no need to masturbate his brain.

- classic and correct. This is an example of how our 'experts' can take a reasonably straightforward question, run it to 76 posts and still not provide a proper answer.

[aterpster]

BOAC:

- classic and correct. This is an example of how our 'experts' can take a reasonably straightforward question, run it to 76 posts and still not provide a proper answer.

Only the certificate holder and the government holding that certificate can provide the "proper answer" to the question posed.

In any case, threads like this do expand by follow-on questions and comments posed.

Isn't that what an Internet forum is about?

[BOAC]

DH and 9.G - I'm sure you know this link, but I dug it out from Google in case it casts any light on the topic.

http://www.ecacnav.com/downloads/4.2...y%20Airbus.pdf

[divinehover]

Thanks for the laughs guys.

We are in discussion with the HK Authorities and I'll provide the formal answer soon.

DH

[FlightPathOBN]

DH,
Well good luck! At least you no know more about RNP procedure design than you ever hoped for Keep us informed on what happens, of course now we all want to know!

He's an operator like me and sitting in the cockpit before departure my only concern is CAN or CAN'T I fly it?

If you had approval, you wouldnt be sitting there wondering, you would already know.

As far as the A340-300, sure it can be RNP capable. If that particular airline ordered enough equipage, or if the certs have been maintained, there is no way for any of us to guess....

In the US, it has been difficult for the airlines. Many of them spent quite a bit of money getting equipped, certified, and trained, only to find out they seldom get to use RNP. Just as with alot of the CATIII ILS, the airlines are letting the calibration, certs, and recency expire, to save money on costs.