Questions tagged [navigation]

Navigation is the process of planning and controlling travel from one location to another. There are many methods of navigation using different techniques and instruments.

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14
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2answers
14k views

What is the purpose of a Victor Airway?

I see lots of great questions related to Victor Airways, but I haven't seen any which indicate why someone would want to fly one or what really makes them special or unique. I get that they are ...
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1answer
1k views

Do some modern VORs not spin? [duplicate]

Today in Ground School we learned about radio navigation. I read here that the rotating part of the VOR rotates at 1,800 RPM (wow! Is it an electric motor that spins it?) We know that modern Active ...
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1answer
350 views

Aircraft Turns - is there a 'pre-turn'?

I've travelled from Vancouver to London often enough to see this phenomenon as something that happens regularly enough to notice. I'm just not sure why. So... the route from Vancouver to London is ...
9
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2answers
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How wide is the cone of confusion above a VOR and NDB?

I saw in book that the cone of confusion of VOR is 40 degrees, and NDB is 50 degrees of each side! Isn't it too much? Maybe it's a mistake, or old information(book printed in 2004) Clarify please: ...
7
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1answer
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Can crews hand-fly an RNP AR approach in IMC?

Required Navigation Performance (Authorization Required) approaches require multi-crew with special training and strict equipment, similar to ILS CAT II/III. Typically, the aircraft must have at ...
7
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1answer
961 views

Why are some seemingly major waypoints nowhere to be found on sectionals (including enroutes)?

I'm looking at the BNTLY.CAVLR3 arrival at KIAD: Almost none of the waypoints (BNTLY, CAVLR, COINZ, etc.) are on a single sectional or chart, enroute or otherwise. Considering this is such a major ...
3
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2answers
794 views

Do GA aircraft pilots use predefined routes (via GPS or DME/VOR vectoring) or methods such as GPS-direct/ VOR-to-VOR in UC airspace?

Example: Flying from RIC to IAD, the most popular and "efficient" route is BENTLY -> CAVLR3: However, you could more simply depart north out of the RIC Class-D, intercept the BROOKE VOR ...
5
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1answer
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Does an Airbus A320 Navigation Display depict constraints for flightplans other than the primary?

When any other flightplan (Missed Approach, Alternate, Temporary, Secondary) except the Primary flightplan is depicted on the ND in an Airbus A320 and the CSTR (constraint) button is pressed on the ...
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What happens if a commercial airplanes navigation system completely failed during a flight?

What would happen if all of the the navigation systems (such as GPS & INS) in a commercial aircraft completely failed? Could the aircraft land safely without all the navigation aids?
3
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1answer
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Why do we have to manually tune VOR receivers?

As the VOR frequency is automatically selected when the DME is selected, under what system conditions is manual tuning of the VOR required? (aviation-safety-bureau.com)
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1answer
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How are NATs connected to European Airways?

The North Atlantic Tracks connect Northern Europe to North America. To enter/exit NATs over North America, the North American Routes (NARs) are used. Questions: What about the European side? What are ...
5
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1answer
520 views

Is there any reason to have ADS-B out that is not based on GPS?

The ADS-B system is only as accurate as the location data source it uses. In the US the 2020 ADS-B mandate requires that horizontal location data be from a GPS source with minimum performance ...
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3answers
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Is Autopilot NAV setting useful?

In flight simulator, using the NAV setting directs the Autopilot to follow the FMS' pre-setup flight plan and will navigate the aircraft through each of the configured waypoints. In real life, ...
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1answer
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What is altitude above surface / ASFC?

ASFC is an acronym frequently seen in official European publications, e.g. used by the French AIS: Also in some ICAO ones, e.g in Annex 4 (Aeronautical Charts) to the Chicago Convention: The ...
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1answer
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Is the 250kt limit below 10,000 feet MSL varied according to airfield height?

FAR part 91 Sec 91.117 for example states that "unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 ...
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2answers
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Do modern aircraft still have mechanical sensors as backup to GPS?

A comment here Why does "no aircraft cross directly over the pole"? indicates that modern aircraft use GPS for navigational purposes, which makes perfect sense. However, do these aircraft ...
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2answers
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What's is the difference among ECL, CFL, RFL, TFL messages in ATM?

These are several messages to provide a change level during air navigation. Some are sent or requested by the pilot, others by the air traffic controllers, etc. There are subtle differences. Could ...
9
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1answer
9k views

How does the ADF null positions find where the NDB is?

I understand how it operates for the most part, although I don't understand how the null positioning works. This image below doesn't include the sense antenna that limits it to one null position, ...
13
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1answer
3k views

What causes the phase to change in a VOR?

I get the light house analogy, and how the VOR essentially works, although I'm wondering what actually causes this phase shift? As it hits magnetic north the variable and reference signal are in phase,...
13
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1answer
6k views

How to calculate the heading correction with a circular flight computer?

While flying between 2 points 120 nautical miles apart, after about 40 nautical miles we discover we are 5 nautical miles off to the right of the track. What heading correction is necessary in ...
4
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1answer
1k views

What is the difference between RFL and ECL in Air Traffic Control?

There are two messages to change the Flight Level: RFL and ECL. However, I don't know the differences. Can anyone explain them?
6
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1answer
3k views

How to calculate the wind variation?

Given the: True Heading = 070 degrees True Track = 061 degrees True Air Speed = 120 knots Ground Speed = 118 knots what is the wind variation? these are the steps I am taking to calculate the ...
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2answers
240 views

Which frame of reference is used to calculate ground velocity? [closed]

During flight, in which frame the ground velocity components are calculated? in the body frame or in the earth frame?
7
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4answers
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Why does this chart seem to show airports with magnetic variation up to 90 degrees?

I am trying to understand some plots of the earth's magnetic variation (declination) by trying to correlate what I see in a figure like the one below with the variation reported for some airports. I'm ...
28
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2answers
13k views

Why does IRS alignment take so much time?

Home GPS systems (like your car navigator) is able to locate you in like a few seconds, but 737NG needs to align itself for 6-8 minutes. Why do navigation systems in aircraft take so long to align ...
8
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1answer
16k views

How do you calculate the true bearing from a station (QTE)?

Assuming that : You are flying on a compass heading of 141°, The compass deviation is given as +3°, The variation read on the chart is 3° East, The wind correction angle is +10° and The relative ...
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2answers
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What do aviation agencies do to make waypoints sequences more easy to remember to prevent navigation mistakes? [closed]

Inspired by this question. What examples are there of waypoints strung together on airways or approaches which are funny or tell a story in order to help controllers and pilots reduce navigation ...
2
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2answers
3k views

Why 360 degrees is in the top instead of 90 degrees in aviation? [closed]

Normally on 2D map, if there is point say A(0,0) in the center and there is point B in the 2nd quadrant . The angle is always in 90<=x<=180. But in aviation, it is 270<=x<=360 . Why ? ...
5
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1answer
945 views

What are outer marker horizontal dimensions at 3 degrees ILS path?

What is the outer marker "distance" along the flight path of a 3 degree ILS? I provide my two approaches below, but as they contradict each other, I am asking this question to learn the proper answer....
4
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3answers
878 views

When should a PPL student start learning navigation?

A big part of the ground syllabus for PPL training is navigation and flight planning. The ground training feeds into practising navigation in-flight and of course eventually to the qualifying cross-...
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2answers
4k views

How are you supposed to get the East/West variation on this question in the FAA PPL written exam?

While taking a practice test, I needed to calculate the magnetic heading between two airports. Most of the time I run into a problem, the map will provide me with isogonic lines with the East/West ...
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2answers
841 views

How can a pilot fly a distance of 594 NM connecting two VOR's?

I was researching worldwide airway designations when I stumbled upon this airway in Brazil: G678 with an MEA of 15,000 feet and a distance of 594 NM (nautical miles) between navaids. It's drawn ...
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0answers
166 views

Is there a "maximum" airplane count in the visible sky at a given location? [closed]

At night, I look at the planes in the sky and count them. I can normally spot between 2-5 planes, never more. As the visible sky is always a constant area and there are security distances and aerial ...
12
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3answers
3k views

What is the purpose of wide area multilateration?

From what I understand the wide area multilateration (WAM) technique is similar to Loran-C but reversed: The aircraft ADS-B transponder broadcasts a signal received by several ground stations. The ...
8
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3answers
7k views

Does True Course, Magnetic Heading, or Magnetic Course determine cruise altitude?

Imagine I plot a course on a sectional chart. The straight line plotted reads a 345° course. The nearest isogonic line is 14° W (so +14°). Weather information calls for a wind correction of +2°. Since ...
6
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2answers
1k views

What was the range of a low-frequency radio range station?

The low-frequency radio range is a historic navigation aid that was in use from the 20's to the 70's. I find it quite interesting. Using AM frequencies, what was the range of a high power LFR station?...
3
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1answer
3k views

How is the terrain displayed on the ND in a A320?

When you turn on "TERR ON ND" in a A320, you see terrain info on you navigation display (ND), but where does its source come from ? if data comes from FMGS stored inside its memory, then how come it ...
9
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1answer
642 views

How can pressure pattern navigation be applied to light airplanes?

I want to attempt max range flights in a single engine piston airplane using pressure pattern navigation. My goal is to achieve greater efficiency than what is published in the POH while still using ...
17
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3answers
5k views

Why don't aircraft fly over Tibet?

If you open www.flightradar24.com or their app, then this is what the scene commonly looks like: As you can see, the South-Central China area is strangely empty and the aircraft look to take a ...
2
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1answer
851 views

Why do commercial flights avoid overflying Shandong Province?

I noticed this a few months ago on a flight to Shanghai. Since then I've been looking on FlightAware occasionally, and every flight I've seen on a similar route has made a turn to the east just before ...
4
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1answer
2k views

What equipment does an A320 need in order to operate under RNP 2?

What are the aircraft equipment/systems eligibility requirements for Airbus A320 airplanes to operate in RNP 2 airspace?
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2answers
2k views

What happens if a student busts Dallas Fort Worth bravo airspace? [duplicate]

What would happen if a student busts a corner, exceeds the floor of Bravo airspace by 500 feet then descends after one minute? The pilot is on the frequency of a Golf airport heading towards a Delta ...
5
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1answer
295 views

Why might a moving map Android app consistently record altitude off by 120 feet?

I fly Cessna 172 and Cherokee Warrior both older models without a GPS. I have a very useful freeware navigation app on my android phone which is really good in every regard other than it always reads ...
6
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1answer
687 views

What trajectory do I fly if bearing angle is constant?

Let's suppose I am flying at constant bearing (initial and final heading are equal and constant) relative to the geographical north pole; what kind of trajectory would I be flying?
4
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1answer
946 views

What are en-route VHF marker beacons (75 MHz)?

ICAO Annex 10, Volume 1 contains a section that gives the specification for en-route VHF marker beacons. What are they? I suspect they are a relic of the past. Are they still in use anywhere in the ...
13
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1answer
1k views

What are those 5-character alphanumeric waypoints?

On the following High IFR chart from skyvector.com I notice along the meridian at 30' intervals there is a green symbol the same shape as an RNAV waypoint. Next to them are 5-digit identifiers, but it ...
4
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2answers
898 views

What is the reason for the detour flight route from AUH to BEY?

I recently flew from Abu Dhabi to Beirut and I was intrigued by the flight route. Instead of simply avoiding Syrian airspace (as would be expected) and flying across KSA, Jordan and Israel, we flew ...
21
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2answers
18k views

What is the difference between conventional VOR and Doppler VOR?

There are two types of VOR (VHF Omnidirectional Range) navigation beacons; the conventional VOR (CVOR) and the Doppler VOR (DVOR). What are the differences between them? Specifically I would like to ...
6
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1answer
412 views

Why isn't the course fixed along an airway?

Why does in some cases magnetic course (not magnetic variation) change between navaids along a same airway? Isn't it supposed that a straight line in an aeronautical chart representing an airway has ...
7
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2answers
7k views

Is it true an ILS CAT IIIc can automatically taxi-in an aircraft?

I've always wondered how would the theoretical (since no airport/plane has it) ILS CAT IIIc guide the plane off the runway? I mean from the perspective of radio signals. What component in the ILS ...

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