Alberta Compass Roses

[JVader]

Hello, I need to do a compass swing on my aircraft and was wondering if anyone knows some airports with compass roses I could fly to other than YYC...

Thanks

[FlyGy]

Mr. Google tells me that Olds-Didsbury has one. I can see one at Red Deer on Google Earth.

[JVader]

Awesome, to Olds I go, thanks for your help!

[FlyGy]

You might wanna call someone there to verify it for you.

[azimuthaviation]

Google earth also shows a compass rose at cyxd, but it doesn't show that its in an area that has subsequently been closed to aircraft movements.

[azimuthaviation]

A compass rose would need to be calibrated at regular intervals in order to be used to do compass swings and still adhere to the regs. Who calibrated to what standard and how do you guys who use them document that in your paperwork?

[cgartly]

Could one get away with using a GPS and a large enough area to taxi around on?

[Colonel Sanders]

Calibrating the compass rose does not make it into my top 1000 priority list.

[azimuthaviation]

Calibrating the compass rose does not make it into my top 1000 priority list.

Oh I concur, I think lifes too short to consider nonsense like that. But there's a building not too far from you that's filled with people whose reason for getting out of bed in the morning is for things like that. And since they issue me licenses I gotta do what they want, regardless of how ridiculous it may seem.

[Colonel Sanders]

That's amazing, AA. If someone actually sent me a letter
stating that I had to calibrate my compass rose, I would
frame it and hang it on the wall for posterity.

[Tiredoldcoot]

I haven't used a compass rose since Billy Bishop was an air cadet! IF the customer wanted it done, on the ground I used a "Master Compass" - I've had one for centuries! It's still sitting in the basement! It'll probaly sit there for ever now that I'm retired!

Usually what I do/did is, when I know the aircraft was coming in for an insepction, I'd go flying with the customer and do an air swing while he or she was flying.

I figured it would be a lot cheaper for the customer, rather then burning his fuel for 10 - 15 minutes taxing in circles! Since He /she paid for the fuel, he might as well burn it off flying! Plus I got more then a few hours flight tome when I was done.

[Colonel Sanders]

Most precise way to set a heading indicator is on a runway with an instrument approach procedure. It will give you the magnetic track of the runway to a tenth of a degree.

If you're going to bother swinging a compass, do it accurately, in the air, at cruise RPM and cruise attitude with all equipment running, pilot with headset on, etc. This requires a good heading indicator, set as above.

[Tiredoldcoot]

Chicken licker:

Exactly! I do (or I used to do) both ends of the spectrum! I flew for a living, I bent wrenches for a living! Anything I worked on, I'd put my kids in and fly!

[Hornblower]

Wow ... don't get me started. Jvader, don't waste your time. If you fly the aircraft the you should have an idea how accurate the compass is; if you don't, you need to pay more attentiuon when you're navigating. If you think your compass is off, check it on the ground with a handheld GPS, then see if it stays close to accurate in the air. Something tells me that you don't even use it, or you would know if it's right or not. Assuming you are compliant with CAR 625.86, it has already been extremely accuratly calibrated at the last out-of-phase NSMDI calibration ... right ... ??? hahahahahahahahaha

Oh yah - don't waste your time and money flying to an airport that has a compass rose that is more out of whack than your ship mounted unit.

[JVader]

I do use it frequently, but after doing some changes to the plane the compass now varies 30-40 degrees verified by taxiing runways... Now assuming the compass rose is far away from building or any large pieces of metal is it not safe to assume the compass rose is safe to use? Magnetic variation doesnt change that much does it? I need to go to olds for gas anyways...

Colonel, can you go further into your compass swinging technique? Do you just get dial up a localizer, set dg, then do your swing? I'm simply night vfr and lacking a Nav radio...any other ways of doing things?

[Colonel Sanders]

Ok. Assuming you have a heading indicator which does not
precess too badly, this is the ideal way to swing your compass:

Taxi out. Ensure vacuum is at correct (4.5 - 5.5) suction at
idle RPM - we want the gyros already spun up!

Set your heading indicator on a runway with an IAP as per the
approach plate. They are insanely accurate. Take off, keep the
ball in the center, level off at a safe altitude and turn - rate one,
ball in the center - to north.

Using your non-ferrous screwdriver, take out all the error on N
with the N/S compensator screw. Now do a level rate one turn to
east. On east, take out all the error with the E/W compensator
screw. Turn to south (rate one, ball center) and take out HALF of
the error with the N/S screw. Turn to west, take out HALF of the
error with the E/W screw.

That's it! You are done! All we need to do now is record the results.

Write down the compass indication when the heading indicator
reads west. Now turn right (rate one, ball center) to 300, 330,
N, 030, 060, E, 120, 150, S, 210, 240 and write down the
compass readings when the heading indicator reads the above.

Now do a gentle approach and land on the same runway, and
verify that your heading indicator has not precessed - that way,
we know that we had good data going into the process.

If you bother to spend the time to do the above, you will have
a perfectly swung compass. Frankly, if you can't bother to do
it right, just copy last year's numbers - that's what most people
do anyways.

People here won't like it, but lacking a good heading indicator,
you could substitute a GPS.

[JVader]

Thanks Colonel, now to find a non-ferrous screwdriver!

[Colonel Sanders]

When I can't find one, I make one from a sliver of 2024-T3 (shrug)

[iflyforpie]

A brass welding rod does the trick as well.

[JVader]

^Awesome idea....reasons like these are why I come to AvCanada.. Thanks for all the help