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mrbarry
09-08-2014, 01:46 PM
i am a new member in an EAA chapter .
it was suggested at this months meeting that as a project that a Compass Rose [aka compass calibration pad ]be located on the home field.
i did not volunteer to research.
has any group done this ?
my research indicates compass calibration pad iaw AC 150/5300-13A Appendix 6 requires quite the complex geomagnetic survey.
http://www.faa.gov/documentLibrary/media/Advisory_Circular/150_5300_13A.pdf
appx 6
pg 257
Appendix 6.
Compass Calibration Pad


i wonder if the county surveyor could perform to standard adequately to satisfy FAA requirement .
an example of a SOW would be :
A total field magnetic survey of the compass calibration pad. A Total Field Magnetometer will be used to determine if the site is clean of magnetic materials.
A declination survey of the compass calibration pad site to determine the average declination of the compass calibration pad and determine whether the compass calibration pad meets the current standards.
Determinations of true north and magnetic north.
Location where radials should be painted on the compass calibration pad to within one minute of arc of the average measured declination of the site. 12 ordinals .
True azimuths to at least three permanent structures.
Installation of permanent bronze survey markers on the compass rose marking the center of the compass rose, true north, true south, and magnetic north. Markers shall be stamped with appropriate information and recessed below pavement surface.

to me a perfect finished install would be
properly located pad iaw reference marked iaw :
Figure A6-1-compass calibration pad marking marking layout

4 brass pins marked as required : center of pad , TRUE NORTH ,TRUE SOUTH and MAGNETIC North..
year &date of survey
MN [magnetic north ] and box the compass as shown
and in center section [where the aircraft sits] . big letters EAA 734 visible from 10K feet AGL

suggestions , criticisms ,remarks
response is required .

4170-
1
.
Worlds largest Compass Rose Edwards

skyfixer8
09-09-2014, 06:21 AM
Barry, contact your local chapter of the 99's. They have a project where they are putting compass roses on any airfield that wants one. There used to be one at each airport with the airport name pre WWll. The gov't had them all removed. Now they are re doing them. The one we have here at Sawyer airport in Michigans Upper Penninsula was laid laid out by the local avionics shop using a master compass. Took the local chapter with help from EAA chapter about 2 1/2 days to do. Due to shifting magnetic declination over a period of time, they will not be 100% accurate, but will get you within tolerances. As an aside, the ones done by the 99's usually will incorporate a local icon painted within the rose.

Wilfred
09-09-2014, 10:02 AM
I laid out an east/west/south/north line on my taxiway using sun noon to get geographic north, them applied magnetic angle for my location and did a compass calibration on my plane. No rose at the airport.

You will never be able to align your aircraft so precisely on a rose so that it is positioned without some error, so absolute minute corrections don't really mean too much. Also if your aircraft compass is off by, say, 1-degree, will that make any real difference in flight? I doubt anyone could maneuver a plane so precisely that it would make any difference.

Also is there anyone who actually flies using a compass now days? With GPS so universally being used, the compass it a relic from the past.

Bob Meder
09-10-2014, 05:38 AM
I laid out an east/west/south/north line on my taxiway using sun noon to get geographic north, them applied magnetic angle for my location and did a compass calibration on my plane. No rose at the airport.

You will never be able to align your aircraft so precisely on a rose so that it is positioned without some error, so absolute minute corrections don't really mean too much. Also if your aircraft compass is off by, say, 1-degree, will that make any real difference in flight? I doubt anyone could maneuver a plane so precisely that it would make any difference.

Also is there anyone who actually flies using a compass now days? With GPS so universally being used, the compass it a relic from the past.

Yes. Flying assigned headings in IFR. Admittedly, it's usually off of the DG or HSI, but those always referenced to the compass.

Greg Wilson
09-13-2014, 07:17 AM
I laid out an east/west/south/north line on my taxiway using sun noon to get geographic north, them applied magnetic angle for my location and did a compass calibration on my plane. No rose at the airport.

You will never be able to align your aircraft so precisely on a rose so that it is positioned without some error, so absolute minute corrections don't really mean too much. Also if your aircraft compass is off by, say, 1-degree, will that make any real difference in flight? I doubt anyone could maneuver a plane so precisely that it would make any difference.

Also is there anyone who actually flies using a compass now days? With GPS so universally being used, the compass it a relic from the past.
Yes their are a few of us out here still. I routinely fly behind the mighty Continental A-65 while following a Bendix compass. They and paper have not let me down yet batteries havehttp://eaaforums.org/images/icons/goggles.gif

mrbarry
09-14-2014, 11:42 PM
(http://fas.org/nuke/intro/aircraft/afman32-1123.pdf)http://fas.org/nuke/intro/aircraft/afman32-1123.pdf

done right the survey is quite complex .
check out
Figure A11.1. Magnetic Field Survey Sheet.
and
Figure A11.2. Layout of Compass Rose

center point bronze marker will be stamped "Center of Calibration Pad." established date, Lat & long nice but not required

True North-South. A north and south control point will be set on a "true north-south" line established through the center of the calibration pad marker.
bronze pins
true north , true south . established day/month /year
then
a magnetic north pin :
bronze marker stamped "magnetic north " established day/month year, declination - degrees minuets

attachment 11
COMPASS CALIBRATION PAD (CCP) MAGNETIC SURVEY

A11.1.
Contents.
This Attachment describes the procedures for performing a magnetic survey for new or
existing CCP by a state registered land surveyor. These surveys will determine the following:
A11.1.1. Suitability of a particular site for use as a CCP.
A11.1.2. Variations of the magnetic field within the surveyed area.
-------------------
i still like the markings specified by AC 150/5300-13A , appx 6 fig A 6-1
http://www.faa.gov/documentLibrary/media/Advisory_Circular/150_5300_13A.pdf

6 inch wide orange stripes with Inch and a half white border radial . , marked every 30 degrees [ magnetic] with the compass headings painted in big orange numerals at the end. ..blocked as shown by reference
i have seen images of the 99's product. . and read some published procedures ,
http://www.99s-sciotovalley.org/pdfs/Compass%20Rose.pdf
if a member of the 99's was to log on here i have a remark on procedure, has to do with pins , the 99's procedure says drive a nail center point , material not specified, removal not specified.

my intent is to produce a CERTIFIED CCP ..
i saw one guy say he did not think there were 4 each certified left ,in country
can not locate reference of certified compass calibration pad locations ..
can not locate reference on required data submissions to certify a CCP ,

i was not the specified researcher on this proposed project . however i have done a deal of research .

should i be allowed to present. my proposed course of action .
location to be determined by apt manager to abide by ref: AC 150/5300-13A , appx 6
magnetic survey by city or county surveyor. [state registered land surveyor] field is county/city owned .
deliverable from surveyor: a document describing the methodology. , 4 each bronze pins, plates,markers permanently set ,properly marked , true north, center point ,true south , Magnetic North . day month year : declination ,
maybe that should be the local EAA chapters contribution , 4 bronze markers set and marked.
painted marks every 30 degrees , magnetic. [12 each] .
..
then since my proposal is to mark to FAA standard [ref: above] get the city county road line painting dudes to lay down the six inch wide orange radial lines , ..

paint a great big "EAA 734 Paris TN" center section

declination on the local sectional rat abt the field is 2 west .. it would be interesting to see how far apart the true north and magnetic north pins got surveyed and set ..and which way .
all that east is least and west is best confuses me

dusterpilot
09-15-2014, 05:34 AM
Be sure to select a location as far away from hangars and other metal structures as practical and also avoid any underground structures (old iron pipes, buried power lines, runway light control lines, etc.)

mrbarry
09-15-2014, 01:07 PM
its all in the Advisory Circular referenced.
AC 150/5300-13A Appendix 6

600 feet from major magnetics , 300 feet from buildings , 150 feet from grates

http://en.wikipedia.org/wiki/Magnetic_declination


(http://en.wikipedia.org/wiki/Magnetic_declination)