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12 votes
Accepted

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

JERIT is the FAF for the LOC approach, as indicated by the Maltese cross. However, the FAF for the ILS approach is not JERIT; it is the Glide Slope Intercept Point (at 2000 ft indicated altitude) ...
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10 votes

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

It does, but it's a different issue than just positional accuracy. The goal of RNAV is to keep the aircraft within the confines of the specified airspace. Longitudinally, you will always be within the ...
  • 18.4k
8 votes

What are RNP and ANP in area navigation?

RNP is a numerical value that refers to the level of performance required for a specific published procedure. If the procedure has an RNP 10, then the on-board navigation equipment must be able to ...
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7 votes
Accepted

Why is there a GPS/RNAV waypoint co-located with a VOR?

In the US, the FAA has done this alot, as in their long term plan to phase out a lot of the VORs. Doing that, they're preemptively just adding a Fix for procedures on top of the VOR so they don't have ...
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7 votes
Accepted

Why do RNAV airways exist?

RNAV freed aircraft from the airways that were already in place that may have zig zagged from VOR to VOR, but with the limitations of the ATC system based on human controllers, it is still desirable ...
  • 114k
6 votes
Accepted

Does ATC prefer ILS over RNAV?

As egid pointed out, pilots typically do not file a specific approach as part of their flight plan. ATC will decide what runways and approaches are in use based on the weather. As the pilots are on ...
  • 70.1k
6 votes

Why are there no RNAV (ILS) approaches?

You are confusing some terminology. RNAV (GPS) approaches can have several different sets of minima. See the example RNAV (GPS) Y 28L at O'Hare: It has: LPV LNAV/VNAV LNAV sets of minima. LPV is an ...
6 votes

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

First of all, an RNP 1 procedure requires a GPS/ GNSS. And as you have said, it requires an inbuilt navigation monitoring and an alerting system. On the other hand, an RNAV 1 procedure does not. In ...
  • 1,833
6 votes
Accepted

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

Once you select and tune NAV 1 or NAV 2 (assuming the NAV 1 or NAV 2 Navaid has associated DME) and then select the "Hold" mode the DME will stay on that frequency after you change the NAV ...
  • 24.2k
6 votes
Accepted

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

Your Question: "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 ...
  • 24.2k
5 votes
Accepted

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

No. The FMS does not use rhumb lines. All RNP/RNAV flight path legs are geodesics. The only exceptions are RF legs (a constant radius circular path about a turn center) and hold legs (a closed ...
  • 18.4k
5 votes
Accepted

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

In ICAO DOC 9905 (Required Navigation Performance Authorization Required Procedure Design Manual) you can find the following definition in Chapter 2.1 RNP APCH versus RNP AR APCH 2.1.1 RNP ...
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5 votes
Accepted

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

Short answer: there seems to be no general plan to replace airways with Q and T routes. The FAA originally proposed replacing them, but the final rule doesn't include it. You can review the source ...
  • 70.9k
5 votes

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

A conventional hold based on legacy radio-navigation required overflying the hold fix on entry as guidance is only available inbound to the fix and your exact position is known at the fix (with some ...
  • 18.4k
4 votes

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

The approach above appears to be associated with the Antonio Marino Airport, Colombia, South America: (I don't know if it is current or proposed) Descent below the published DA/H is not permitted due ...
  • 24.2k
4 votes

What are the "parts" of a SID procedure?

FAA Order 8260.46F - Departure Procedure (DP) Program describes "... the policy, guidance, and standardization for initiating, developing, processing, and managing the Departure Procedure (DP) ...
  • 24.2k
4 votes
Accepted

What is the reason to have LOC/VNAV landing method?

A VNAV with localiser approach is normally a backup to a regular ILS should there be a glide slope unserviceability. The use of VNAV to manage the vertical portion of the approach would allow the use ...
  • 1,219
4 votes
Accepted

How does CDI scaling transition from terminal to approach sensitivity?

Beginning 2NM prior to reaching the final approach fix of an activated approach, the GPS will smoothly taper down the CDI scale from 1-NM full-scale deflection (from the center) to 0.3-NM at full-...
4 votes

What is GPS HIL in layman's terms?

The true position of an aircraft in flight can be measured, but the accuracy of any measurement is limited. The actual measured position is the actual true position plus the actual measurement error. ...
  • 10.7k
4 votes

Why are there no RNAV (ILS) approaches?

The gist of your question is whether it is possible to couple RNAV with ILS? The following ILS chart of Cochin Airport (VOCI) is an ILS approach where Initial and Intermediate approach are executed ...
4 votes

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

Like a chart might state, RNAV 1 and then state that you require a GNSS. This essentially makes the procedure an RNP 1 procedure. Not correct. “RNAV1 – GNSS required” means that you can fly the ...
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4 votes
Accepted

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

There is a way to do this in a 737NG using the FMC FIX page: 1 FIX Name Enter the desired fix. Valid entries are airports, navaids, waypoints or runway identifiers from the navigation database. [...] ...
  • 50.3k
4 votes

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

Unfortunately in the US many of the regulations are written to make it difficult to separate accuracy/integrity in the along-track direction from the cross-track direction. DO-229D claims this is &...
  • 6,483
3 votes

Why are there no RNAV (ILS) approaches?

RNAV(GPS) procedures being combined with LPV or LNAV/VNAV, which are Landing Systems Your confusion here is that LPV is a landing system which it is not. It is a way of saying your GPS is going to ...
  • 97.7k
3 votes
Accepted

Does EASA allow using a portable GPS for RNAV capability?

The answer, broadly is no, handheld GPS units can not be used for IFR RNAV routes (or approaches for that matter). To know if a specific GPS unit is legal for IFR navigation you need to check up on a ...
  • 97.7k
3 votes

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

The FAA website predicts pre-flight whether RAIM will be available The RAIM algorithm will tell you during your flight if GPS is working correctly. The pre-flight FAA website check is not a ...
  • 76.5k
3 votes
Accepted

What are the "parts" of a SID procedure?

Yes, a SID can have three parts as you described. The runway transition defines the path from each runway to get to the common route section of the SID. All runways then share the common route section....
  • 70.1k
3 votes

What are the "parts" of a SID procedure?

You asked the question in terms of ARINC 424 which imposes the constraints of the database structure and use. So I'll try to explain SIDs within that constraint and in the broader sense. The reason ...
  • 18.4k
3 votes

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

Since "radar" means "ATC radar", I'm not sure how a pilot could substitute anything for it. The issue isn't that the pilot needs radar to navigate the approach; it's that's ATC needs radar in order to ...
  • 70.9k

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