Offline Action80

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Re: i dont understand someone help please
« Reply #80 on: May 11, 2021, 10:22:53 AM »
You missed my point, that being all kinds of operating systems evolve, with some functions being labeled as being based on "something," not really necessary to the function or continued successful operation or even actually based on to the reason given.

For instance, I use a computer everyday with Windows as the operating system. Maybe we should check with them as to whether everything in place for their operating system is necessary or helpful.

I think we both know the answer to that question is a firm "NO."
There is only one possible purpose for a drift nut, though, isn't there? It causes the gyro to precess by up to 15 degrees per hour. There is no possible reason to have that feature if there wasn't a need for it. It's not like some legacy software code that's tangled up with something essential and can't be removed. Moreover, users can easily disable the feature by setting it to 0 latitude - the equator. But nobody does that, because that would be silly. From a personal perspective, I've flown aircraft that actually have the drift correction selectable in the cockpit and, yes, we always made sure we set it right.
Gyroscopes do not need a drift to function.


Here is where the attempt at a diversion takes place.  A gyro does NOT need a drift nut to function.  The gyro part will indeed spin and provide a nice steady indication of an azimuth without the drift nut, but that azimuth indication probably won't be accurate. A spun up and stabilized gyro has to be set to a useful reference azimuth so it's accurate and provides useful information to the pilot. That's why you always use the DRIFT NUT to set the directional gyro to your runway heading (that's always accurately known) just before your start your takeoff roll.  Then if the control tower says something like 'fly heading 235 and climb and maintain 5000' you can easily use your directional gyro to comply with the control tower's instructions.  If you didn't you would have to note what the gyro indicated after it spun up, then do some quick mental math, and turn to the heading as instructed.
Seems to me you are admitting they don't need drift nuts to function and neither does the pilot need a gyro with a drift nut to fly the plane to the destination.

The bottom line is, the gyro will work without a drift nut just fine but you will need to use that drift nut many times during your flight to save yourself from having to calculate an error differential that will continuously take place during the flight.  It's a known and verified fact that if you fly a straight heading, say directly along geographic North line, for a length of time, your directional gyro will continuously drift off the 360 (or 0) degree indicated heading as the earth rotates.  The gyro is working fine and is following the laws of physics but the drift nut is for the convenience of the pilot. As for my source if information:  FAA issued commercial pilot's license and experience as pilot in command over a period of about 30 years.
Yes, you confirmed everything.

You do not need a gyro with a drift nut to fly.

Basically, it appears a drift nut is merely something of an automated process that provides additional information that was already available to all pilots and capable of being performed regardless.
You are correct in certain aspects but you are still trying to hide the most important reason of why a drift nut is needed.  Let's start with a practical scenario.  A pilot starts up his aircraft and gets everything warmed up.  The directional gyro stabilizes at a indicated heading of 236 degrees.  Assume the aircraft is sitting on the ramp at a heading of 093 degrees. That means that the gyro indicates 143 degrees more than the actual aircraft true heading but the gyro is working perfectly well and will stay at that heading but will slowly change as the earth rotates under the aircraft.  The pilot next taxies out to runway 14.  That means the actual runway heading is at a geographic heading of about 140 degrees.  So before takeoff with the aircraft aligned with the runway center line the directional gyro will then indicate 283 degrees.  You take off and the control tower gives you instructions to turn left to heading 125 degrees for traffic avoidance.  Now you have to do some quick mental math you could just add 125 + 143 and turn to a gyro indicated heading of 268. 


You probably are starting to get the picture.  The drift nut doesn't change anything about how the gyro actually works but it does save the pilot a lot of mental arithmetic and probably avoids plenty of mistakes that could happen at critical times.  On top of this as the earth spins and takes the atmosphere and the aircraft with it the directional gyro's heading accuracy will slowly become inaccurate.  This means that the pilot will then be required to have a stopwatch as well to keep track of the drift of the azimuth as a function of time.  These days you could probably just have an iPhone app to keep track of everything, but 50 years ago when I was first starting to fly we didn't have all the high tech stuff like that.  Instead a drift nut was installed on the directional gyro.  Again, it didn't actually have any effect on how the gyro works or the gyro's accuracy, but it did make the directional gyro a whole lot more of an effective instrument that the pilot could use for his navigation between point A and point B.       
Why would I try to hide something that is not needed?

Seems you are attempting to ascribe extreme relevance to something that turns out be a matter of simple convenience.

In other words, without Google Maps installed on your phone, getting to grandma's house for Thanksgiving dinner wouldn't be possible.

That's your argument.
Now you have gone into trolling mode with your comments. 

I've explained in detail what the drift nut is used for on a directional gyro and how it greatly reduces a pilot's workload and that's a particularly important safety issue.  You could get out your stop watch and every 20 or 30 minutes during the flight mentally factor in a couple of degrees of compensation needed to make your gyro give you your correct heading to compensate for the rotation of the earth or you could just have a drift nut.  Pilot's convenience or SAFETY ?   

As for going to grandma's house I just go over the river and thru the woods to grandmother's house I go. THE HORSE KNOWS THE WAY TO CARRY THE SLEIGH.......So no, it's not me that need the iPhone and Google maps.   
The fact I have pointed out a drift nut isn't necessary to perform the operations involved in flight is now labeled as trolling.

Pot meet kettle.

Pilots were not getting out their watches every twenty or thirty minutes either.

All forms of long distance traveling, regardless of form, is split into more easily manageable sections.

We are done here.

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Online Iceman

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Re: i dont understand someone help please
« Reply #81 on: May 11, 2021, 12:10:50 PM »
You guys really need to stop quoting entire blocks of threads. It makes this beyond stupid to try to read...

Offline SteelyBob

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Re: i dont understand someone help please
« Reply #82 on: May 11, 2021, 06:24:21 PM »
Again, I am not muddying things by using your source. It is plainly evident from your source that Sigma Octantis could not possibly be visible in all three places at once because it is not dark enough in all three places at once.

Dark enough.

Dark enough.

Your source.

Your source.

ETA: Sigma Octantis not useful for navigation due to the fact it is barely visible. Perhaps it maybe not even a "pole star."

My source:



The dark shaded bit = official 'night', ie twilight over, sun more than 18 degrees below horizon. See the dark shaded bit on the east coast of South America and the West coast of Australia? That's dark. The city of Recife in Brazil, for example? Dark. Africa? Dark. West coast of Australia? Also dark.

Maybe the satellite (sorry..guess you don't believe in those) image will help with visualisation:



Quite happy if you want to dispute this, but you'll need to come up with something better than 'your source says it's not dark enough', when it quite clearly, most definitely says it is.


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Offline RonJ

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Re: i dont understand someone help please
« Reply #83 on: May 11, 2021, 06:45:44 PM »
There are some who think that the drift nut on an aircraft directional gyro really isn't necessary for the gyro to work.  That part is true, but that's not the real issue here.  When the directional gyro does spin up it's stabilized indicated azimuth is completely random and has no relationship to which direction the aircraft is pointing at the time.  There will be a random offset displayed and that offset will slowly drift as the earth rotates on it's axis.  That part is a confirmed and verified fact by aircraft pilots including myself.  Now do you actually need a drift nut for the directional gyro to work?  Technically, NO.  But the information displayed by that gyro would be much more useful if you had a drift nut so you could reset the displayed azimuth to a much more useful reference point, the current heading of the aircraft.  It's really just that simple.


You could say that mankind doesn't really need the internet.  I survived for a long time before my first internet connection was installed.  You don't need a fancy telephone.  My grandmother had a crank telephone with no dial on it.  You cranked the phone and told the operator what number you wanted to call.  You don't need a color flat screen TV.  The TV I used to watch as a kid was a black & white one with a round screen about 12 inches in diameter.  Heck, you don't even need a wheel.  The caveman survived before any kind of round thing and just hunted animals for survival.  So which way do you want to go, forward in technology or backwards? 


Go ahead, take that drift nut off every pilot's gyro, he doesn't really need it.  Let those pilots use their brains to calculate the heading offsets mentally every time they need to.  Hopefully no pilot makes a mistake and collides with another aircraft and the wreckage falls on my house. 
You can lead flat earthers to the curve but you can't make them think!

Re: i dont understand someone help please
« Reply #84 on: May 11, 2021, 08:13:23 PM »
Over several pages RonJ has patiently explained the function, use and need for the drift-nut in increasingly basic terms, and still Action80 doesn't seem to get it. 

How about this?  You can use the drift-nut, or you can work it out in your head, or you can use pencil and paper, or an I-phone.  What you can't do is ignore it.  One way or another, if you want to travel further than grandma's house, you need to compensate for something on your directional gyro. 

Its there, its real; now what do you suppose that something is? 

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Offline stack

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Re: i dont understand someone help please
« Reply #85 on: May 11, 2021, 08:33:00 PM »
Again, I am not muddying things by using your source. It is plainly evident from your source that Sigma Octantis could not possibly be visible in all three places at once because it is not dark enough in all three places at once.

Yes, Sig Oct is somewhat faint. However, it can still be seen from all three continents, South America, Africa, and Australia, at the same time. Using Stellarium here is the Southern Cross from Cape Town, South Africa, Perth, Australia & Ushuaia, Argentina, 3 continents, same time:



As a bonus the Southern Cross, right next to Sig Oct, is brighter and it too can be seen from the three continents at the same time - Using Stellarium here is the Southern Cross from the same locations, all at the same time:


Re: i dont understand someone help please
« Reply #86 on: May 26, 2021, 09:47:56 PM »

Again, I am not muddying things by using your source. It is plainly evident from your source that Sigma Octantis could not possibly be visible in all three places at once because it is not dark enough in all three places at once.

Dark enough.

Dark enough.

Your source.

Your source.

ETA: Sigma Octantis not useful for navigation due to the fact it is barely visible. Perhaps it maybe not even a "pole star."
 

Probably pointless, but just for the record;

Good News:  According to the twilight tracker, 21.30 UTC today, 26 May 2021, it is currently astronomical nighttime in Perth (Australia), the entire continent of Africa, and Recife (Brazil). 

Bad News:  I am not in any of those places. 

Further Good News:  This situation will happen nightly, lasting longer each night, peaking around June 21, if @Action80 is in a position to pop down there with a compass and telescope.