Questions tagged [rnav]

Questions about RNAV, meaning Area Navigation, which allows aircraft to navigate between waypoints not marked by radio beacons on the ground.

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9 votes
5 answers
463 views

Do GPS coordinates of a fixed point in space ever change?

As I understand, GNSS uses the WGS84 model of the earth to pin-point points in 3D space. However, once the GPS coordinates of a point in space have been determined (say a GPS waypoint), do it's ...
1 vote
0 answers
149 views

LPV, WAAS/EGNOS and GLS in 737 NG

As far as I understand, there are mainly 3 types of RNP approaches: LNAV/VNAV - we have a set of fixes with altitudes and flying it LPV WAAS/EGNOS - same as 1, but aircraft use special receiver ...
2 votes
1 answer
397 views

In what situations can LNAV/VNAV minima be higher than LNAV minima, such as RNP Approach to Runway 16 in Corfu?

I recently flew the RNP approach for runway 16 into Corfu. While reviewing the approach charts, I noticed something unusual. The LNAV/VNAV minima is set higher than the LNAV minima for this particular ...
0 votes
0 answers
42 views

When are you established on an RNAV segment under ICAO rules?

In the U.S. it is when you are within 1X the required accuracy. I have not been able to find the source publication for ICAO.
4 votes
1 answer
69 views

Why was the rate of part 121 LPV equipage projected to be so low, and has that projection come true?

On page 10 of the FAA's 2016 PBN Navigation Strategy document, found here, the USA part 121 fleet is very thoroughly equipped with RNAV capability....except for LPV. Similarly, the FAA predicted that ...
1 vote
1 answer
125 views

Can I fly a SID/STAR if a navaid is NOTAMed inoperative, using RNAV?

Take a SID like this, BARPI2K at LJPZ. The textual Route description says BARPI TWO KILO Climb on track 315 to 1700 ft; LT to PZ L; overhead PZ L; LT on HDG 295; intercept PZ QDR 325 PZ L to BARPI. ...
0 votes
0 answers
36 views

What are the equipments that are able to meet RNP specifications?

In recent times onboard the aircraft, what are the equipments that are able to meet RNP specifications?. Many articles that i have read says at present only GNSS (IFR Certified GPS with RAIM or WAAS) ...
3 votes
1 answer
181 views

1. Why does the glide slope guide you down to 0.7NM away from the runway? 2. Best way to circle from 28 to active runway 36?

Why does the glide slope guide you down to 0.7NM away from the runway? 2. Best way to circle from 28 to active runway 36? Note parachute jump site takes place on SE corner
1 vote
0 answers
45 views

Does RNAV 5 requires certification in Japan?

Through the last question, I learned that the C-130H is an aircraft capable of RNAV 5. Then my colleagues raised another question. "According to the US Airforce manual, it is true that RNAV 5 is ...
2 votes
2 answers
297 views

How is RNP's onboard performance monitoring and alerting system represented in the cockpit?

I'm trying to understand what is exactly onboard performance monitoring and alerting system related to RNP. Does it display some extent of deviation or just beeps as alarm? And if that system exists ...
3 votes
1 answer
193 views

Can I fly RNAV 5 with only INS?

First of all, I'm not a native English speaker, and this is my first question, so please understand that it can be very awkward. My military C-130H aircraft has DME/VOR, TACAN, ILS, and INS (EGI, LN-...
0 votes
0 answers
100 views

Why do they say PBN is under RNAV?

PBN exists under the umbrella of area navigation (RNAV). [FAA AIM, Section 2. Performance-Based Navigation (PBN) and Area Navigation (RNAV)] As far as I know, RNAV and RNP exist under PBN, and as an ...
0 votes
0 answers
79 views

What is the difference between RNAV-Terminal usage waypoints vs RNAV-STAR waypoints?

What is the difference between [MM604 (or) MM615] vs [RADAB (or) DAMAD] in the STAR attached below When seen using Enroute Chart The description for RADAB or DAMAD is: The description for MM604 or ...
9 votes
1 answer
841 views

Should IFR flight plans in the USA still have one waypoint per sector in 2023?

Alternate title: How come ATC has cleared aircraft direct from Laredo to Columbus 17 times? If you hop on ForeFlight today (Feb 20 2023) and search for suggested routes between KLRD and KCMH you'll ...
2 votes
1 answer
536 views

Does EASA allow using a portable GPS for RNAV capability?

Assume an older IFR-certified aircraft with the classical equipment, that is two VOR/ILS receivers with plain CDIs, ADF and DME, but no GPS. It can be flown IFR, but many routes can't be used, because ...
7 votes
2 answers
581 views

Does RNAV and RNP specify what type of longitudinal accuracy the system has?

I understand RNAV 1 to mean it will be within 1 mile of the desired track 95% of the time, but that is lateral accuracy, what about longitudinal accuracy, in front and behind the estimated position ...
1 vote
0 answers
268 views

Along Track Distance ATD

ATD (Along-Track Distance) is used by ATC for certain types of (rare) NON-Radar Separation. I am training as an Air Traffic Controller in the USA. I have been told the only way to know if an aircraft ...
6 votes
2 answers
2k views

What is RNAV transition and what is the difference between RNAV transition and RNAV STAR

Can someone explain what is RNAV transition and what is the difference between RNAV transition and RNAV STAR. Because sometimes both types of procedures are published for an airport and I don't know ...
5 votes
1 answer
325 views

How do you calculate the deviation from an RNAV waypoint radial?

As a clarification at the beginning: I'm talking about non-GPS, pure VOR-DME based RNAV devices here. On RNAV devices that use just the selected VOR-DME, not GPS, the phantom radio station is set up ...
5 votes
4 answers
373 views

How to monitor MSA sector from an RNAV waypoint in the 737?

For instance, at Manchester (EGCC) the approach procedure for RNP 23L has the MSA based off of RNAV waypoints; DOMIG bearing 142 to 322, OSNAP bearing 322 to 052, TINVA bearing 052 to 142. From NATS ...
5 votes
1 answer
584 views

What does a DME indicator do in HOLD or RNAV mode?

I found this DME indicator on the Cessna 210. Its mode switch has four positions - NAV1, NAV2, RNAV and HOLD. NAV1 and 2 are clear - it uses the NAV1 and 2 freq respectively. I'm wondering what the ...
7 votes
1 answer
2k views

What is the difference between a conventional and an RNAV holding?

While reading in the PANS-OPS (Doc 8168-OPS/611 Volume II) about holding procedures, I came across Chapter 7 of Part III section 3 defining RNAV holding procedures ...
3 votes
0 answers
935 views

Can I fly an RNAV DP (GPS & RNAV 1 required) with no FD/AP?

I’m currently planning an instrument flight which includes a full stop at an airport with a RNAV (Obstacle) Departure Procedure. The procedure plate requires RNAV 1 and GPS. In ground school I ...
5 votes
1 answer
1k views

What does "height loss" mean on an RNAV (RNP) approach plate?

While viewing the following approach chart, which is an RNAV(RNP) CAT C Approach, there are several landing minima, stating a HEIGHT LOSS OF 50' AND 150', what does that specifically mean?
10 votes
2 answers
5k views

What should I do if I intercept the glideslope before reaching the final approach fix?

On several of the ILS and RNAV LPV approaches in my area (and notably the ones I expect for my checkride), I consistently intercept the GS at 0.1-0.2nm before the FAF. An example: I am flying at ...
4 votes
2 answers
2k views

Vector to final on RNAV approach with the Intermediate and final segments are not aligned

Consider the RNAV 30 approach to C83 (Byron, CA), On a recent training flight requesting vectors for the approach, ATC pointed us to the MOVDD IF before cutting us loose (informing us that we would ...
5 votes
3 answers
857 views

Why do RNAV airways exist?

I assume there's some stupidly obvious reason that I'm missing, but why bother creating RNAV airways when I thought the entire point of RNAV was not needing to fly along a suboptimal preset path? I ...
5 votes
3 answers
3k views

What are the "parts" of a SID procedure?

In the ARINC 424 (downloadable from this link), the following information about SIDs procedures is given in the section 5.7 Route Type (RT TYPE): As you can see, it appears to me that a procedure is ...
3 votes
4 answers
3k views

Why are there no RNAV (ILS) approaches?

While studying the PBN (FAA Order 8260.58A) and TERPS (FAA order 8260.3D) documents, I still have some trouble figuring part of the logic behind the naming and definitions of the published IAP Charts. ...
7 votes
1 answer
366 views

Why would there be two RNAV waypoints co-located with a VOR?

Similar to this question but more so! The Enroute H-5 chart shows two RNAV waypoints over Spinner VORTAC (SPI): SOHOW and USIRE. Neither waypoint appears on the Low IFR charts, nor on the VFR charts. ...
3 votes
1 answer
2k views

How does CDI scaling transition from terminal to approach sensitivity?

I read in the AIM that WAAS vector modes will provide a linear course width of +/-1NM prior to the FAF and then provide a fixed width of +/-0.3NM to the point where an ILS splay would be 0.3NM and ...
4 votes
2 answers
385 views

Are VOR airways being replaced by RNAV routes as VORs are decommissioned?

I understand that VORs in the US and elsewhere are being removed from service gradually. The FAA plans to maintain a Minimum Operational Network, but still I imagine many VOR airways will also have to ...
3 votes
3 answers
3k views

Is it legal to use GPS to navigate VOR Airways?

A previous question concludes that it is legal to fly an aircraft in the US with only an IFR-approved GPS/WAAS system and no other navigation equipment on an IFR flight plan. My question is about how ...
7 votes
2 answers
6k views

Why RNAV SIDs and STARs are RNAV 1 instead of RNP 1?

I am studying for my CFII check-ride and I was wondering to know why SIDs and STARs are not RNP 1 but RNAV 1? Let's start with the following two definitions RNP - Required Navigation Performance: It's ...
-3 votes
2 answers
347 views

What is the purpose of aircraft localization? [closed]

I want to understand what is the purpose of doing localization while an aircraft is flying? What sensors are used by the instruments that do this localization of an aircraft? Is there more than one ...
6 votes
1 answer
966 views

What is the lowest RNP approach requirement without being RNP AR?

I was recently told by a friend that as soon as RNP for an approach is below the 1.0/0.3nm standard that it is required to be RNP AR. At least here in Australia, a curved segment anywhere on the ...
0 votes
0 answers
186 views

What is P-RNAV?

I came across the term P-RNAV. What is P RNAV, and what are the differences from 'standard' Area Navigation(RNAV)? Is there a specific set of requirements for P RNAV?
5 votes
1 answer
2k views

What is GPS HIL in layman's terms?

GNSS Horizontal Integrity Limit/ Horizontal Protection Level is a measure of GNSS position error/integrity that's very important in RNP operations and RAIM, but it has an obtuse definition in aviation ...
0 votes
1 answer
900 views

Does the term track guidance apply only to conventional procedures?

In ICAO's 8160 "Aircraft Operations" manual there is a term called "track guidance", for which I can not find any clear definition. A few examples: Departure Procedures 3.1 3.1.1 There are ...
2 votes
1 answer
724 views

What are the ICAO GNSS waypoint naming conventions?

I'm curious about ICAO naming conventions regarding GNSS and RNAV waypoints. Would I be correct in assuming that all GNSS area waypoints are 5 letters, and RNAV waypoints are 6? What about waypoints ...
3 votes
1 answer
134 views

Are rhumb lines ever used as leg paths for RNP/RNAV?

Are rhumb lines ever used by an FMS as leg paths for RNP/RNAV? If so, what arinc 424 leg type would use them?
2 votes
0 answers
37 views

Does a Navigation Specification characterize all legs of a terminal procedure?

I am studying the different parts of Instrument Flight Procedures, as they are described by FAA's manuals, such as the Aeronautical Information Manual, TERPS and Performance Based Navigation. For ...
21 votes
7 answers
86k views

What is the difference between LNAV/VNAV and LPV minimums on an RNAV approach?

This approach shows two sets of minimums that both have vertical guidance with a Decision Altitude (DA). What is the difference between LNAV/VNAV and LPV, and why does LPV have lower minimums?
1 vote
1 answer
1k views

What does mean 'GS' in RNAV (GPS) Chart?

Hello. I have a question about 'GS' in my RNAV(GPS) Approach Chart. Usually, (Including PAPI, VASI whatever...) Normal Glide Descent Angle means 3.00 degree. but some 'GS' says 3.07, 3.04, 3.09 ...
0 votes
1 answer
64 views

Has mod percent changed for Mark-1 glide slopes?

Mark-1F glide slopes operate at 80 percent modulation. What was it for earlier versions i. e. Mark-1C, Mark-1D, etc.
2 votes
1 answer
2k views

confusion between RNAV and RNP approaches and specifiations [duplicate]

Ive been really confused between these two specifications recently. For example my research suggested that RNP has on board monitoring and alerting and RNAV doesn't require this, however then why must ...
5 votes
1 answer
14k views

What are RNP and ANP in area navigation?

What are Required Navigation Performance (RNP) and Actual Navigation Performance (ANP)?
2 votes
1 answer
3k views

Does ATC prefer ILS over RNAV?

Listening to APP for several major (US class B) airports, it seems that every flight is vectored to intercept the localizer. Is it really possible that 100% of flights filed an ILS approach? If so, ...
0 votes
1 answer
527 views

Substitute Suitable RNAV system for Inop Radar on approach “requiring” Radar

Assuming my aircraft's navigation equipment is a "Qualified/Suitable RNAV System," as defined by AC 90-108, is it legal for me to fly the LDA Y Rwy 19 IAP to DCA with ATC Radar out of service? Here ...
5 votes
2 answers
14k views

Must RAIM be checked in flight before every GPS approach or is a preflight check acceptable?

My instructor has been teaching me to run a RAIM check for each RNAV approach we do. For some flights this can be 4 or more RAIM checks for the various airports/approaches and adds significantly to ...