Aces High Bulletin Board
General Forums => Wishlist => Topic started by: earl1937 on June 19, 2013, 03:57:04 PM
-
:airplane: Well, since no one has anything else to do, try a little education! Describe "Magnetic Lines of Variation" and what effect does this have at AH headquarters in Texas?
-
Haha, sounds like another idea for the O'club: Quizzes! :)
-
True Earth rotational axis North, versus Earth's magnetic fields North.
Magnetic North varies from region to region due to variances in the earth's magnetic fields. It's why hikers get lost even using a compass. Modern topo and flight maps show regional declinations. Without todays GPS system. Good Navigators were once worth their weight in gold.
Hey Lucy this don't look like your mommas house. You did say due north for 3 hours as the vulture flies..........
-
:airplane: Well, since no one has anything else to do, try a little education! Describe "Magnetic Lines of Variation" and what effect does this have at AH headquarters in Texas?
Does Scotch have magnetic qualities other than outright attraction?
-
http://en.wikipedia.org/wiki/Magnetic_declination
http://www.ngdc.noaa.gov/geomag/img/DeclinationMap_US.png
about 5 degrees east for dallas.
-
http://en.wikipedia.org/wiki/Magnetic_declination
http://www.ngdc.noaa.gov/geomag/img/DeclinationMap_US.png
about 5 degrees east for dallas.
:airplane:You air are correct! Didn't think I would get many response to the question! Most people go through life thinking that the compass points at the North Pole! Little do they know that what the magnetic compass points at is about 700 miles away from the North Pole. (Think that mileage is close on distance, but really can't remember for sure).
-
and its moving too :)
-
and its moving too :)
:airplane: Not sure what you are referring to by "moving", as the "true North Pole" and the magnetic pole has been in the same places for millions of years!
-
:airplane: Not sure what you are referring to by "moving", as the "true North Pole" and the magnetic pole has been in the same places for millions of years!
the magnetic pole moves quite a bit. constantly in fact.
apparently about 41km a year.
http://en.wikipedia.org/wiki/North_Magnetic_Pole
(http://upload.wikimedia.org/wikipedia/commons/0/0a/Magnetic_North_Pole_Positions.svg)
-
and then once in a while it flips end over end, which is why you can tell the sea floor is spreading
-
the magnetic pole moves quite a bit. constantly in fact.
apparently about 41km a year.
http://en.wikipedia.org/wiki/North_Magnetic_Pole
(http://upload.wikimedia.org/wikipedia/commons/0/0a/Magnetic_North_Pole_Positions.svg)
:airplane: Good answer! Just remember, the mineral deposit which attracts your compass is, as I indicated, in a fixed position in the earth, but as the earths magnetic fields ebb and flow thu time, as your chart indicates, the actual magnetic field moves. Good answer though and thanks to GPS and other navigational aids in todays aviation industry, we don't have to worry with figuring plus or minus when navigating.
-
it still means something enough to the FAA that they still put it on the terminal procedures airport diagrams :)
(http://img811.imageshack.us/img811/6114/52r4.jpg)
-
it still means something enough to the FAA that they still put it on the terminal procedures airport diagrams :)
(http://img811.imageshack.us/img811/6114/52r4.jpg)
:airplane:Your point is correct, but the reason they do is if your have complete electrical failure and don't have a Ipad or notebook with you that has that ILS system in it, then you gotta do it the old fashioned way!
-
?? Why wouldn't everyone know this? Map and compass is taught in grade 7, and beyond that, half the people on this forum are licensed pilots.
-
:airplane:Your point is correct, but the reason they do is if your have complete electrical failure and don't have a Ipad or notebook with you that has that ILS system in it, then you gotta do it the old fashioned way!
that doesn't make any sense. :headscratch:
how would knowing true heading help with an instrument approach in an emergency.. all the bearings on an instrument approach are magnetic, all headings given by atc are magnetic.
and also, I've never heard of an ipad or notebook with an ILS receiver (have seen handheld vhf's with VOR mode tho) -- maybe you mean GPS. Even so, those headings are magnetic also.
-
that doesn't make any sense. :headscratch:
how would knowing true heading help with an instrument approach in an emergency.. all the bearings on an instrument approach are magnetic, all headings given by atc are magnetic.
and also, I've never heard of an ipad or notebook with an ILS receiver (have seen handheld vhf's with VOR mode tho) -- maybe you mean GPS. Even so, those headings are magnetic also.
:airplane: About 2 weeks ago, I saw a story on CNN, concerning a pilot flying what looked like a Beech single engine aircraft, who complete failure of electrical system and he was talking about an "ap" for his "Ipad, which he used to shoot the approach and land safely.
(http://i1346.photobucket.com/albums/p684/earl1937/bth_echarts-jeppview-category_zps883f31b1.jpg?t=1372794419)
I am not sure, but I believe this is a photo of a Ipad or something, by which you can download instrument approach and navigational charts, On Jeppensen.com web site.
If you were, say, somewhere in California and had nothing but your magnetic compass to give your direction and you were getting radar vectors for landing, say a ASR approach to Burbank, and he told you to fly 090, what heading would you line your compass on to fly that heading?
-
:airplane: About 2 weeks ago, I saw a story on CNN, concerning a pilot flying what looked like a Beech single engine aircraft, who complete failure of electrical system and he was talking about an "ap" for his "Ipad, which he used to shoot the approach and land safely.
(http://i1346.photobucket.com/albums/p684/earl1937/bth_echarts-jeppview-category_zps883f31b1.jpg?t=1372794419)
I am not sure, but I believe this is a photo of a Ipad or something, by which you can download instrument approach and navigational charts, On Jeppensen.com web site.
If you were, say, somewhere in California and had nothing but your magnetic compass to give your direction and you were getting radar vectors for landing, say a ASR approach to Burbank, and he told you to fly 090, what heading would you line your compass on to fly that heading?
well you can use google maps for the same thing using an android based phone also.
semp
-
If you were, say, somewhere in California and had nothing but your magnetic compass to give your direction and you were getting radar vectors for landing, say a ASR approach to Burbank, and he told you to fly 090, what heading would you line your compass on to fly that heading?
if the dude in the tower is telling me to use a heading of 090 knowing that i have nothing but the compass to go by...he better mean the same heading that compass is giving me or there will be hell to pay if i survive the landing.
-
:airplane: About 2 weeks ago, I saw a story on CNN, concerning a pilot flying what looked like a Beech single engine aircraft, who complete failure of electrical system and he was talking about an "ap" for his "Ipad, which he used to shoot the approach and land safely.
(http://i1346.photobucket.com/albums/p684/earl1937/bth_echarts-jeppview-category_zps883f31b1.jpg?t=1372794419)
I am not sure, but I believe this is a photo of a Ipad or something, by which you can download instrument approach and navigational charts, On Jeppensen.com web site.
If you were, say, somewhere in California and had nothing but your magnetic compass to give your direction and you were getting radar vectors for landing, say a ASR approach to Burbank, and he told you to fly 090, what heading would you line your compass on to fly that heading?
090. atc gives magnetic headings.
as for the ipad / etc. sure you can shoot a non precision approach with gps in a pinch, but it isn't ILS.
-
if the dude in the tower is telling me to use a heading of 090 knowing that i have nothing but the compass to go by...he better mean the same heading that compass is giving me or there will be hell to pay if i survive the landing.
:airplane: Burbank has a 15 degree East variation, and lets assume when the A&P set your compass correction card on the local compass rose that it was "zero", then to fly a 090 heading, you would add 15 degrees to the desired track, i.e., 105 degrees to make a 090 magnetic track on the ground, which is what the controller is wanting you to do.
-
090. atc gives magnetic headings.
as for the ipad / etc. sure you can shoot a non precision approach with gps in a pinch, but it isn't ILS.
:airplane: An ASR is a non-precision approach procedure. It is a "Area Surveillance Radar", and the radar operator will give your headings and altitudes to fly as you approach for landing.
-
:airplane: Burbank has a 15 degree East variation, and lets assume when the A&P set your compass correction card on the local compass rose that it was "zero", then to fly a 090 heading, you would add 15 degrees to the desired track, i.e., 105 degrees to make a 090 magnetic track on the ground, which is what the controller is wanting you to do.
you're getting things mixed up, I think.
the compass correction card is due to variations in the airplane/compass itself. (steel parts, magnetic fields, etc) so yeah, you might have to make a correction but that's just for reading your own compass.
the 15 degrees of magnetic declination is already accounted for when atc tells you to fly 090. (they want you to point the plane at magnetic 090, not true 090)
-
:airplane: An ASR is a non-precision approach procedure. It is a "Area Surveillance Radar", and the radar operator will give your headings and altitudes to fly as you approach for landing.
yeah I've read about it.. aka "surveillance radar approach".. they are very rare as far as I know.. I think its more a military thing?
I was talking about how gps can pretty much replace any navaid in a vor /dme / ndb / loc / sdf approach.
-
that doesn't make any sense. :headscratch:
how would knowing true heading help with an instrument approach in an emergency.. all the bearings on an instrument approach are magnetic, all headings given by atc are magnetic.
and also, I've never heard of an ipad or notebook with an ILS receiver (have seen handheld vhf's with VOR mode tho) -- maybe you mean GPS. Even so, those headings are magnetic also.
Seriously? :confused: Runway 16 with a variance of (for portland as given as an example) 16.2 degrees?
-
Seriously? :confused: Runway 16 with a variance of (for protland as given as an example) 16.2 degrees?
the runway numbers are based roughly on the magnetic heading eg. 163.4 degrees = rwy 16.. and they change, because the north pole drifts.
that's how this thread started.
great example, seattle . the runways run true north-south. they are numbered 16/34, not 18/36
correction:
the earth's magnetic field is moving, not just the north pole.
-
you're getting things mixed up, I think.
the compass correction card is due to variations in the airplane/compass itself. (steel parts, magnetic fields, etc) so yeah, you might have to make a correction but that's just for reading your own compass.
the 15 degrees of magnetic declination is already accounted for when atc tells you to fly 090. (they want you to point the plane at magnetic 090, not true 090)
:airplane: The compass correction card is for the things which you mention, which are permanent installed on the aircraft. While the variation is built into the navigational charts, you still have to apply the correction yourself in the cockpit, in order to fly the heading you were instructed to fly. After a career of 22,634, accident free flight hours, I kinda think I know what I am talking about.
-
:airplane: The compass correction card is for the things which you mention, which are permanent installed on the aircraft. While the variation is built into the navigational charts, you still have to apply the correction yourself in the cockpit, in order to fly the heading you were instructed to fly. After a career of 22,634, accident free flight hours, I kinda think I know what I am talking about.
with all due respect,
magnetic deviation is different than magnetic declination (variation).
I think you have confused the two.
http://en.wikipedia.org/wiki/Magnetic_deviation
http://en.wikipedia.org/wiki/Magnetic_declination
-
with all due respect,
magnetic deviation is different than magnetic declination (variation).
I think you have confused the two.
http://en.wikipedia.org/wiki/Magnetic_deviation
http://en.wikipedia.org/wiki/Magnetic_declination
:airplane: I understand the two and the difference, but not sure what you are questioning. If you are instructed to fly a 090 degree heading on your compass in the aircraft, at Burbank, you would have to fly a 105 degree heading on your compass. Easterly varaitions are added to the magnetic heading you are trying to fly East and Westerly varations are added to the heading when flying West Bound.
Magnetic deviation is the error induced in a compass by local magnetic fields, which must be allowed for, along with magnetic declination, if accurate bearings are to be calculated. There are no charts to my knowledge, which you can pull out and look at, which shows local magnetic field, except on sea going vessels!
The track on over the ground is all the radar operator sees, but it is up to the pilot to fly the correct magnetic heading, to produce that 090 degree track on the radar screen!
-
:airplane: I understand the two and the difference, but not sure what you are questioning. If you are instructed to fly a 090 degree heading on your compass in the aircraft, at Burbank, you would have to fly a 105 degree heading on your compass.
that is wrong. unless your compass is actually 15 degrees off.
-
You surely won't be flying a precision approach with an app unless you have hardware interfaced that can "read" the ILS and other signals.
The amount of lawyering and the approval process of such hardware would be a huge undertaking so expect something as mentioned above to cost a few thousand dollars.
Also....I'm not so sure that you can't fool the gyroscope/acclerometer combo. in current devices by pulling Gs while in any position other than upright......which is how some pilots who can't read instruments are also fooled into thinking that they are upright in IMC when they are actually nowhere near upright.
-
that is wrong. unless your compass is actually 15 degrees off.
:airplane: Your compass in the aircraft is NOT compensated for magnetic variation. You have to apply the variation mentally to know what correct magnetic bearing to fly. That is why the maps have the lines of variation on them, so that a pilot can apply the correction to his compass while flying.
If you are thinking that your compass automatically compensates for variation, sir, you are incorrect. You, the pilot have to apply the variation to fly the correct course desired.
-
You surely won't be flying a precision approach with an app unless you have hardware interfaced that can "read" the ILS and other signals.
The amount of lawyering and the approval process of such hardware would be a huge undertaking so expect something as mentioned above to cost a few thousand dollars.
Also....I'm not so sure that you can't fool the gyroscope/acclerometer combo. in current devices by pulling Gs while in any position other than upright......which is how some pilots who can't read instruments are also fooled into thinking that they are upright in IMC when they are actually nowhere near upright.
:airplane: I have never used anything like what we are discussing, but I do know that your Ipad, with the proper app, can interp the GPS system infor and the app super=imposes a small aircraft on the app, which represents your position. I can see where it would be of assistance in lining up with the correct runway, and with the correct soft ware program, don't see why it couldn't pickup glide-slope and localizer signal.
-
:airplane: Your compass in the aircraft is NOT compensated for magnetic variation. You have to apply the variation mentally to know what correct magnetic bearing to fly. That is why the maps have the lines of variation on them, so that a pilot can apply the correction to his compass while flying.
If you are thinking that your compass automatically compensates for variation, sir, you are incorrect. You, the pilot have to apply the variation to fly the correct course desired.
I'm not saying the compass compensates for it, i'm saying it doesn't matter at all when you're being vectored.
when atc tells you to fly 090, they mean magnetic 090. not true 090, or a fly a ground track of 090.
from the faao 7110.65:
5-6-2. METHODS
a. Vector aircraft by specifying:
1. Direction of turn, if appropriate, and magnetic heading to be flown, or
PHRASEOLOGY-
TURN LEFT/RIGHT HEADING (degrees).
FLY HEADING (degrees).
FLY PRESENT HEADING.
DEPART (fix) HEADING (degrees).
-
I'm not saying the compass compensates for it, i'm saying it doesn't matter at all when you're being vectored.
when atc tells you to fly 090, they mean magnetic 090. not true 090, or a fly a ground track of 090.
from the faao 7110.65:
:airplane: The FAA OCB, which all operators have to know and are tested on before certification as air traffic controller, does not specify only what TRACK he or she wants you to make over the ground or radar screen! Pilots, In order to do that, must mentally apply the variation in that area.
Some aircraft have "adjustable" compasses, which the pilot can apply the variation as he or she flys over the country and then they don't have to make mental calulations as to proper headings to comply with ATC instructions.
(http://i1346.photobucket.com/albums/p684/earl1937/bth_440px-Compensating_magnetic_declination_svg_zps20fabfd9.png?t=1373116971)
How to compensate for magnetic declination when reading a compass. In this example, the declination is 14°E (+14°), so the compass card points to a "north" 14 degrees to the East of true North. To obtain a true bearing, add 14 degrees to the bearing shown by the compass. The operator is only concerned with the bearing that you are from the radar site and which bearing he or she wants you to fly to comply with their instructions.
Hope this clears this up for you sir, I appreciate your reply!
-
:airplane: The FAA OCB, which all operators have to know and are tested on before certification as air traffic controller,
what is the OCB? I've never heard of it and either has google, apparently.
ATC goes by FAAO 7110.65U now.
This is it, and it's current:
http://www.faa.gov/air_traffic/publications/atpubs/ATC/INDEX.HTM
as I had quoted it earlier, they give magnetic headings when vectoring. so you're plainly incorrect, sir.
if a radar vector was an instruction to fly a ground track, they'd expect you to compensate for winds aloft too. which we both know they don't.
again. notice it doesn't say "ground track to be flown" or "true heading to be flown"
5-6-2. METHODS
a. Vector aircraft by specifying: 1. Direction of turn, if appropriate, and magnetic heading to be flown, or
PHRASEOLOGY-
TURN LEFT/RIGHT HEADING (degrees).
FLY HEADING (degrees).
FLY PRESENT HEADING.
DEPART (fix) HEADING (degrees).
-
:airplane: Well, since no one has anything else to do, try a little education! Describe "Magnetic Lines of Variation" and what effect does this have at AH headquarters in Texas?
:aok :cheers:
-
what is the OCB? I've never heard of it and either has google, apparently.
ATC goes by FAAO 7110.65U now.
This is it, and it's current:
http://www.faa.gov/air_traffic/publications/atpubs/ATC/INDEX.HTM
as I had quoted it earlier, they give magnetic headings when vectoring. so you're plainly incorrect, sir.
if a radar vector was an instruction to fly a ground track, they'd expect you to compensate for winds aloft too. which we both know they don't.
again. notice it doesn't say "ground track to be flown" or "true heading to be flown"
:airplane: "Operators Code Book" and it could be called something else today, but was kept by the radar operators side at all times when on duty. And No Sir, I am not wrong!
-
You're wrong.
I really didn't want to be harsh about it, but yes. You're wrong, and are just being stubborn. 22k hours doesn't give you your own reality.
in the future, do not ask quiz questions you do not know/remember the actual answers to.
:neener:
-
forget it