Compass Deviation Card

How to keep the Cessna 170 flying and airworthy.

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rupertjl
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Joined: Thu Jun 17, 2004 5:29 pm

Compass Deviation Card

Post by rupertjl »

Anyone know of a place to download a copy of a compass deviation card? I've searched all over and all I can find are explanations of the card itself. I bought a comapss rebuild kit and one came with it but I lost the darn thing. I just figured I could find one on the web somewhere and print it out.

Thanks in advance!
Jud
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GAHorn
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Post by GAHorn »

If you are referring to the little 1" X 3/4" card that comes with repair kits, they may be found at aviation supply houses and instrument repair shops(usually just for the asking).
Or if you'll send me your mailing address via PM, I believe I have an extra I'll mail you.)
If you are talking about the 3 -1/2" long X 3/4" card that originally came in 53 and later B models, I had one mfr'd at a local engraver on acrylic. They reverse engraved it on it's back, I filled it with the appropriate color Tempo paint, and removed the gloss finish with a 0000 steel wool pad so it'd have a non-glare finish.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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N3243A
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Post by N3243A »

Just order one from Spruce for $1.85 or copy one from another aircraft.

Aside from the FAA regs that require one in the aircraft, who really uses these cards? Anyone? I could go on a rant here about the worthlessness of these stupid deviation cards because the magnetic flux of the earth is constantly changing (variation) to the tune of about 1/5 degree per year (depending on location) rendering the cards useless in 5 to 10 years, but instead I'll just ask if anyone finds them of value? Do you actually steer 89 degrees if you want to fly due East for example? What, your compass intervals are in 5 degree increments and are spaced only 1/8 inch apart and you have a hard time discerning 1 lousy degree to set your DG by? Well you get the idea...

Bruce
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GAHorn
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Post by GAHorn »

HA! Who'da ever thunk it! Bruce and me on the same page! :lol:
I recently took my CFI-I renewal ride with the feds and he looked at my CDC (compass deviation card) and remarked, " Is that thing accurate? All the desired steering points are exactly the same as all the compass points!"
I merely said, "All the rule says is that I have to have one. If I want to go North, I point it North." 8)
No further discussion occurred about it. :lol:

P.S.- I actually have taxiied all around the compass rose at the airport and the dang thing sure looks accurate, anyway! Don't ask me what position my flight controls were in at the time.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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N3243A
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Joined: Thu Jul 04, 2002 12:51 am

Post by N3243A »

This IS a real shocker!!! Ya know George, I was getting all prepared for you to give me a long story that by steering 272 degrees rather than 270 degrees saved your bacon 12 years ago on a 150 mile trip to Nowheresville TX and that I was all wrong as usual. Guess I'll have to "stand down". 8O
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GAHorn
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Post by GAHorn »

N3243A wrote:This IS a real shocker!!! Ya know George, I was getting all prepared for you to give me a long story that by steering 272 degrees rather than 270 degrees saved your bacon 12 years ago on a 150 mile trip to Nowheresville TX and that I was all wrong as usual. Guess I'll have to "stand down". 8O
It's a simple thing, Bruce! To fly 272 degrees to get to Nowheresville...all you have to do is use 1992 Sectional charts ...so the magnetic deviation matches the last time the compass card was calibrated! (I'd love to see a Fed scratchin' his head trying to figure out how to write that one up!) :lol: :lol: :lol:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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jrenwick
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Joined: Thu Apr 01, 2004 8:34 pm

Re: Compass Deviation Card

Post by jrenwick »

rupertjl wrote:Anyone know of a place to download a copy of a compass deviation card?....
I put together an Excel spreadsheet that prints one the right size for Airpath compasses. It's at http://www.eaa54.org/Ccard.xls if you want to use it. You enter your own N number and correction information and print a card with deviation numbers that might be easier to read than a hand-written one. You can also change the dimensions if what it makes doesn't fit your compass. Instructions are on the sheet.

Happy flying!
John Renwick
Minneapolis, MN
Former owner, '55 C-170B, N4401B
'42 J-3 Cub, N62088
'50 Swift GC-1B, N2431B, Oshkosh 2009 Outstanding Swift Award, 2016 Best Continuously Maintained Swift
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johneeb
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Post by johneeb »

John, very nice. Our airplanes may be from the 1950s but they don't have to look that old.
Johneb
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GAHorn
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Post by GAHorn »

johneeb wrote:John, very nice. Our airplanes may be from the 1950s but they don't have to look that old.
Johneb
HEY!!! What's wrong with lookin' like you're in your Fifties!!?? :wink:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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johneeb
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Joined: Thu Jun 26, 2003 2:44 am

Post by johneeb »

George, There is nothing wrong with looking like we are in our 50's especially for me, in 3 months I will no longer be in my 50's.
Johneb
dkalwishky
Posts: 95
Joined: Fri Dec 06, 2002 2:20 am

Post by dkalwishky »

N3243A wrote:Just order one from Spruce for $1.85 or copy one from another aircraft.

Aside from the FAA regs that require one in the aircraft, who really uses these cards? Anyone? I could go on a rant here about the worthlessness of these stupid deviation cards because the magnetic flux of the earth is constantly changing (variation) to the tune of about 1/5 degree per year (depending on location) rendering the cards useless in 5 to 10 years, but instead I'll just ask if anyone finds them of value? Do you actually steer 89 degrees if you want to fly due East for example? What, your compass intervals are in 5 degree increments and are spaced only 1/8 inch apart and you have a hard time discerning 1 lousy degree to set your DG by? Well you get the idea...

Bruce
I follow the line on my gps.

Dave
rudymantel
Posts: 451
Joined: Sat Nov 23, 2002 4:03 pm

Post by rudymantel »

A friend once asked me to fly his Pitts from Homestead FL to Oak Grove TX. After taking off I realized the compass was wildly out of calibration, like 20-30 degrees ! So I overflew the runways at Tamiami airport and noted what the compass read on a piece of paper. This ad-hoc deviation card helped me to complete the trip with surprising accuracy. No radios, only that compass and previously cut and folded sectionals.
Rudy
doug8082a
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Joined: Tue Apr 23, 2002 2:06 am

Post by doug8082a »

I did a similar trick when my compass was out of whack. I'd overfly an airport and set my DG to the runway numbers. Worked a heck of a lot better than I expected.
Doug
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