Hot answers tagged

10

LNAV/VNAV approaches were originally designed for larger, more sophisticated turbine aircraft utilizing onboard Flight Management Systems (FMS). These types of approaches uses barometric altimeters and ground radio equipment to compute a descent path and add vertical guidance to an existing non-precision approach. An LPV approach still provides vertical ...


10

There's an FAA paper on RNAV approaches that explains the differences between LP, LPV, LNAV and LNAV/RNAV approaches. I made a table for my own reference but since StackExchange doesn't allow tables (AFAIK) here's a summary: LP: no vertical guidance; WAAS required; MDA for minimums LPV: vertical guidance; WAAS required; DA for minimums LNAV: no vertical ...


7

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 calculate its position to within 10 nautical miles. If the procedure has an RNP 0.3, than the equipment must be able to calculate its position to .3nm. ANP is ...


7

LPV is a higher precision approach requiring equipment beyond what is needed for LNAV/VNAV. In particular you need dual WAAS recievers in a certified installation. The improved guidance is what allows the lower DH. See this link for more information.


6

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 to update all the procedures when the VOR is decommissioned.


5

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 their descent to the destination, they will be told which approach to expect. Pilots can always request something different but ATC is trying to get everyone to ...


5

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 racetrack pattern). To quote RTCA DO-236C, Minimum Aviation System Performance Standards: Required Navigation Performance for Area Navigation: RNP Routes and ...


5

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 to keep most aircraft on a "road network" so to speak to make it easy to manage separation, so RNAV airways were created between major centers that provide ...


4

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 of APV minima which are normally lower than using a vertical speed mode. VNAV is a better mode when conducting non-precision approaches as the aircraft is ...


4

FAA Order 8260.46F - Departure Procedure (DP) Program describes "... the policy, guidance, and standardization for initiating, developing, processing, and managing the Departure Procedure (DP) Program." Your questions are broad-based, but Order 8260.46F should provide the answers you are looking for. Here are two figures from Order 8260.46F. These ...


4

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 instrument approach procedure (IAP) with localizer-type precision and with vertical guidance, (hence the name LPV), provides a pilot with a "ILS-style" ...


3

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 variety of paperwork, thats covered in this answer. Strictly speaking if you could find a certified unit it would be legal but there are no current units (to my ...


3

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 to obstacle clearance requirements. Therefore, a "height loss" (amount of altitude expected to be lost during a go-around [missed approach]) is added to the ...


3

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 for that is that ARINC 424 exists to support the use of an FMS (or an RNAV navigator). But some SIDs don't require an FMS to fly them. The ones that start with "...


3

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 substitute for the use of the RAIM function during flight. It will only show whether the RAIM function is available during flight. RAIM stands for Receiver ...


3

. A LPV approach can provide WAAS vertical guidance as low as 200 feet AGL. LNAV/VNAV approaches also provide approved vertical guidance and existed before the WAAS system was certified. At that time, only aircraft equipped with a flight management system (FMS) and certified baro-VNAV systems could use the LNAV/VNAV minimums. Also the design of an LPV ...


2

LPV - Localizer Performance with Vertical Guidance is some kind of enhanced satellite navigation with an required accuracy of 16 meters in the horizontal and 20 meters in the vertical plane during 95 percent of the time, achieved by multiple special GPS (WAAS) receivers. Obviously this accuracy allows to reduce the minima on the approaches.


2

The FAA instrument flying handbook discusses techniques and the procedures by which circling approaches must be conducted.1 You must remain within the protected area or circling radii, but as soon as you enter this area, you may begin the circling maneuver. Usually, this means you will begin the maneuver well before the missed approach point. In ...


2

Sensors From ICAO Doc 9613: 2.2.1.3 RNAV 5 operations are based on the use of RNAV equipment which automatically determines the aircraft position in the horizontal plane using input from one or a combination of the following types of position sensors, together with the means to establish and follow a desired path: a) VOR/DME; b) DME/DME; c) INS ...


2

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. After the common route, there may be multiple enroute transtions to get an aircraft on to the rest of its flight plan. Below is the EPKEE RNAV departure from ...


2

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 allow the approach in the first place. Per this answer, ATC can only clear aircraft for an RNAV approach without an IAF if radar monitoring is available. I ...


2

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 work kind of like an ILS and will have similar horizontal/vertical responses on your way down or as the FAA puts it Localizer Performance with Vertical ...


2

RNAV was/is in the older model where each approach was designed around a specific technology, and any detected failure to meet the (assumed) fixed accuracy of that technology means you can't use the approach at all. RNP is newer ICAO terminology under their Performance Based Navigation model, which essentially means they don't care how you get your ...


1

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 APCH is defined as an RNP approach procedure that requires a lateral TSE of +/-1 NM in the initial, intermediate and missed approach segments (MAS) and a lateral ...


1

ICAO Doc 8168 "Procedures for Air Navigation Services - Aircraft Operations - Volume I - Flight Procedures" states under 2.1.3 Types of SID: Track guidance may be provided by a suitably located facility (VOR or NDB) or by RNAV. To answer your question: RNAV/RNP SIDs are considered procedures with track guidance. The better your tracking is the smaller ...


1

There are no "GNSS waypoints". GNSS is a common position source for RNAV, though not the only one. All RNAV waypoints, like conventional (e.g. VOR/DME) fixes, have an identifier composed of five alphanumeric characters that is unique within a country. Some countries don't use numbers (e.g. the US); others do.


1

The percentage of modulation hasn’t changed, rather the way it is measured. Upon further review the current measurement is 80% SDM (sum), where before the measured value was 40% for 90 & 150 hertz individually. The method of measurement change, may be due to rare case instances where 90 and 150 shouldn’t be exactly equal, but together the sum is always ...


1

You are partially correct, first of all they are called "RNAV routes" not "RNAV airways" and yes the entire point of RNAV was not needing to fly along a suboptimal preset path but that was because of the fact that you flight plan had you flying directly over the navigational beacons. Like this: RNAV routes allow more efficient flight by connecting random ...


1

You have 8 items selected, and the max allowed is 8. There is guidance material from ICAO with steps to follow on how to get down to the 8 (in case you exceed it in the future). Right now you're fine. For example: If having applied the guidance provided in Step 3 there are still more than 8 PBN codes remaining: Identify the capabilities ...


1

Answer lies on AIM 5-1-16 "rnav and RNP operations" paragraph f: f. During the pre−flight planning phase RAIM prediction must be performed if TSO−C129() equipment is used to solely satisfy the RNAV and RNP requirement [...] Operators may satisfy the predictive RAIM requirement through any one of the following methods: [...] 2. Operators may use ...


Only top voted, non community-wiki answers of a minimum length are eligible