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36 votes
Accepted

Why would a pilot need to change their heading when flying through a cold front?

In the Northern Hemisphere, wind usually veers to the right when a cold front passes. If you fly through a cold front, the wind also veers to the right. To maintain a constant track, a correction to ...
Mike Sowsun's user avatar
  • 37.8k
18 votes

Is the Garmin G1000's heading indicator based on a Magnetic compass?

The Horizontal Situation Indicator (HSI) rosette display on a G1000 works in a similar fashion to a conventional HSI operating in slave mode. It is slaved to a 3 axis magnetometer which gives it ...
Romeo_4808N's user avatar
  • 74.1k
15 votes
Accepted

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

1 - First I calculate the track deviation angle: To find the track angle: outer scale: distance off track (NM) in this case 5 NM divided by inner scale: distance already travelled(NM) in this ...
Marcello Miorelli's user avatar
14 votes
Accepted

Does ATC use True Course or Ground Track?

A heading is the direction the plane's nose is pointed. A course is the direction it is actually traveling. The difference between the two depends on wind. A true heading or course is corrected for ...
StephenS's user avatar
  • 27.7k
11 votes

Are aircraft pilots required to fly runway heading for a certain distance?

The initial turn should be made at 400 feet AGL. Unless otherwise specified in the departure procedure, the initial turn should be made when reaching an altitude of 400 feet above the runway elevation ...
Bianfable's user avatar
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10 votes
Accepted

What trajectory do I fly if bearing angle is constant?

The term bearing is not so clear, as the link to another answer in the comment shows. But let's say bearing means the angle between the track (over ground) of an aircraft and a fixed location. This ...
sweber's user avatar
  • 7,267
7 votes

What is an autopilot washout filter?

A washout filter is used in a yaw damper autopilot to remove the steady state component from the yaw rate sensor. Feedback from the rate sensor is used to damp dutch roll mode, but during turns ...
Pilothead's user avatar
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7 votes
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What are Altitude, Attitude and Heading Hold?

These are generally 3 different auto pilot modes. The first two are related to pitch and the third to heading/roll a nice overview can be found here Altitude Hold: Generally speaking setting an ...
Dave's user avatar
  • 101k
7 votes

Does the radial needle of a HSI automatically deflect to the correct position when tuning the NAV radio to a localizer / ILS?

It depends on your instrument suite. If you have just a radio with connected HSI, you have to set the course yourself, because on the radio you only set the frequency and there are hundreds ILS ...
Jan Hudec's user avatar
  • 56.3k
7 votes
Accepted

How do you realign a directional gyro in an area of magnetic unreliability?

You initially align it while on the ground, using a known reference like the runway. While in flight, you'll need to use an astrocompass or sextant, if you have one and know how to use it and can see ...
John K's user avatar
  • 132k
7 votes

What does the number in degrees indicate on an approach chart?

An approach plate is a map, so the directional values presented are always magnetic track angles (except near the magnetic North Pole). A heading is where the airplane points when it's flying. So, ...
John K's user avatar
  • 132k
7 votes

Is the Garmin G1000's heading indicator based on a Magnetic compass?

A good way to figure this out is to look up the annunciation modes of the Garmin display. Here's a Cessna-specific version of the G1000 that I grabbed. This page shows the red X will happen from the ...
300D7309EF17's user avatar
  • 2,400
6 votes
Accepted

How do I determine which radial intercept angle to use?

There is no definite answer to this question. If you are far away from the beacon radials are far away from each other and thus small intercept angle would be insufficient to reach desired track in ...
busdriver's user avatar
  • 3,340
6 votes

Can a commercial pilot decide where to make their turn after departure?

The short answer is yes, a commercial pilot can make a decision when to turn. To clarify a few points though, there really isn't such a thing as a "published vector". If a departure procedure with ...
Michael Hall's user avatar
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6 votes
Accepted

Should I set the runway heading to the course box on G1000 before takeoff or should I set the SID course I will intercept after takeoff?

The G1000 avionics are RNAV capable, or in Garmin jargon "GPS navigation". Even though this SID is the conventional type and does not require RNAV equipment, you can use GPS navigation as a ...
Robert Chapin's user avatar
5 votes

What principle does the attitude indicator in the G1000 use?

G1000 is a multi-unit system. The attitude information comes from a specialised unit called AHRS (Attitude and Heading Reference System), typically GRS 77. AHRS uses two solid-state gyros (vertical ...
Zeus's user avatar
  • 9,083
5 votes

When resetting the heading indicator to match the magnetic compass, do I need to use the compass deviation card?

Yes the DG is supposed to be set to the corrected magnetic indication whenever you set it, so you should mentally add or subtract the degree or two or three based on the closest segment on the card as ...
John K's user avatar
  • 132k
5 votes
Accepted

How do airplanes measure cross-wind?

There is not a specific instrument for this, because it is not directly measurable. Most modern aircraft have digital sensors for heading and airspeed, and their GPS/IRS will know ground track and ...
StephenS's user avatar
  • 27.7k
4 votes
Accepted

What is an autopilot washout filter?

A washout filter is a building block of a control system. As such, it's hard to say exactly where it'd be used, but I'll make some guesses about where it could go. In general it's used for removing ...
RealAnswersNotAI's user avatar
4 votes
Accepted

How would you use the mental clock code to solve this dead reckoning problem?

Step 1: Calculate maximum drift. Max drift $ = \frac{wind speed}{TAS (NM/min)} = \frac{24}{120/60} = \frac{24}{2} = 12$ That means if you have a direct crosswind, you'll need to correct 12$^{\circ}$. ...
Steve V.'s user avatar
  • 23.3k
4 votes
Accepted

How does a flux gate compass system work?

Fluxgates are a way to determine a magnetic field, in this case for navigational purposes. The basic principal is based on the lines of flux that the magnetic field of the planet gives off, a nice ...
Dave's user avatar
  • 101k
3 votes
Accepted

How to visualize compass deviation?

I assume your question is about Declination/Variation, not Deviation that is addressed with the compass correction card. It's confusing because you are reading the compass card from behind so to ...
John K's user avatar
  • 132k
3 votes

Where do I land if I fly from KLAX with a constant east heading, crossing the US and the Atlantic ocean?

Finally I'm adding this update to the answer sweber provided years ago, using current magnetic declination at an altitude of 15,000 ft. It shows a larger deviation. It's not the magnetic declination ...
mins's user avatar
  • 74.8k
3 votes
Accepted

Understanding UNOS and exceptions from it

Because the compass works correctly on east/ west magnetic headings (or on the magnetic equator).1 Suggestion: learn more about how the "dip" of the earth's magnetic field, combined with the ...
quiet flyer's user avatar
  • 22.8k
2 votes
Accepted

How do you find the difference in degrees between two headings?

Figured it out. LH turn: [origin hdg] - [destination hdg] (if less than 0, add 360) RH turn: [destination hdg] - [origin hdg] (if less than 0, add 360) Edit: for the acute angle between two ...
Murey Tasroc's user avatar
  • 1,172
2 votes
Accepted

How does the attitude and heading reference (AHRS) work on Boeing 737 aircraft?

The 737 does not have a separate AHRS. Those functions are simply outputs from the two IRS's. (Source) 737 IRS panel. ATT (attitude) mode selects the AHRS-only output of the IRS.
Ralph J's user avatar
  • 51.8k
2 votes

Flight directional headings

What you are hearing is a departure clearance. ATC is giving instructions to pilots on the ground before they take off on what runway to use and what to do next. 27 Left is the runway, which points ...
GdD's user avatar
  • 54k
2 votes

How do airplanes measure cross-wind?

Yes, it is called a driftmeter and consists of a telescope aimed straight down at the ground. It has a set of scribed lines projected onto its field of view which the navigator can rotate so the ...
niels nielsen's user avatar

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