Compass correction card

cgrab

cgrab

Pattern Altitude
Joined
May 2, 2014
Messages
2,162
Location
Huntsville AL
Display Name
Display name:
cgrab
On today's flight it was light and variable and I was in some empty airspace. I decided to update my compass correction card by flying the 30's compass headings using my GPS and then letting the compass settle on a number and writing it down. I now have a new compass correction card.

Just a reminder for those that forgot there is another thing besides GPS in their planes for finding direction and want to make it right.
 
Even with L&V winds, I don’t know that I’d trust my GPS track to equal heading.

probably ok for a quick & dirty validation (and some of the things I’ve done for that are kind of scary), but probably not accurate enough for a good compass card IMO.
 
You should use your magnetic Gps on the ground to see if your compass is correct.(no wind correction)

The Gps has to have some movement for it to work correctly.

(Do not run into anything)
 
I’m sure he’ll crash and die if an A&P doesn’t sign off his compass deviation card.
Where does this fall on the risk assessment matrix?

97D5B3D6-3377-4084-A848-5A8BDC5F4116.jpeg
 
unsafervguy said:
are you and A&P? that is not a 43 appendix a item. it must be signed off by a A&P
Click to expand...


Maybe, maybe not. I have no idea where a compass card would fall in light of the Coleal letter ( https://www.faa.gov/about/office_or...2009/Coleal - (2009) Legal Interpretation.pdf ) but it might be considered minor and acceptable, since it doesn't require any disassembly or structural modifications.

Appendix A is a sampling, not a hard limiting list, according to FAA legal interpretation.
 
If there's a compass rose at the airport, that's very handy. Tedious, but handy.

Align the longitudinal axis with heading.
Start the engine and turn on all the electronics.
Write down compass heading.
Turn off the electronics
Shut down the engine.

Repeat for the other 7 compass points (NSEW, NE, SE, SW, NW)

Bored now.

This is why the compass will be swung by the shop during annual. First time in many years, years since I installed the SIRS compass.
 
murphey said:
If there's a compass rose at the airport, that's very handy. Tedious, but handy.

Align the longitudinal axis with heading.
Start the engine and turn on all the electronics.
Write down compass heading.
Turn off the electronics
Shut down the engine.

Repeat for the other 7 compass points (NSEW, NE, SE, SW, NW)

Bored now.

This is why the compass will be swung by the shop during annual. First time in many years, years since I installed the SIRS compass.
Click to expand...


Let's see. Compass card correction to half a degree at only 8 cardinal points. Then fly, holding a heading +/- 15 degrees (per ACS) that's based on winds aloft data that might be good to +-/ 20 degrees and +/- 10 knots, if you're lucky.

How useful is that compass calibration?
 
Half Fast said:
Hmmmm....
Click to expand...
In case you didn't know, every AC has that note. Regardless compass accuracy is regulatory and requires a mechanic sign-off just like empty weight/bal/equip list corrections are regulatory and also require a mechanic sign-off. As I mentioned the AC is merely one option on how to perform a compass swing and by whom. ;)
 
Show me a space to sign off the card.

Just because there is a new card, doesn't mean anyone did anything.
 
Bell206 said:
In case you didn't know, every AC has that note. Regardless compass accuracy is regulatory and requires a mechanic sign-off just like empty weight/bal/equip list corrections are regulatory and also require a mechanic sign-off. As I mentioned the AC is merely one option on how to perform a compass swing and by whom. ;)
Click to expand...


Yes, I’m quite aware that advisories are merely advisory.
 
Half Fast said:
Let's see. Compass card correction to half a degree at only 8 cardinal points. Then fly, holding a heading +/- 15 degrees (per ACS) that's based on winds aloft data that might be good to +-/ 20 degrees and +/- 10 knots, if you're lucky.

How useful is that compass calibration?
Click to expand...
ACS is a testing standard, not a flying standard.

I’ve had DR legs of 1.5-2 hours that put me easily within acceptable visual distance of my destination. 4+ hours using pressure pattern navigation (still heading based).
 
Salty said:
I’m sure he’ll crash and die if an A&P doesn’t sign off his compass deviation card.
Where does this fall on the risk assessment matrix?

View attachment 86346
Click to expand...

Given that I'd bet more compass cards have been filled out than ever referenced in flight for navigational purposes, I'd say "far far off of your matrix, down, and to the right"
 
unsafervguy said:
are you and A&P? that is not a 43 appendix a item. it must be signed off by a A&P
Click to expand...

Wait a minute, all he did was write down some numbers on a card. He didn’t say he adjusted anything. Or did I miss something?
 
I replaced my PAI-700 vertical card compass (which failed twice in less than 100 hours and was a ***** to compensate) and correction card with an MGL SP-6 Magnetometer and AV-1 Compass Display. Now I don't need a stinking correction card; it's accurate to +/- 1.5º. No lead/lag!

Another Experimental advantage.

AV-1 Compass Display.jpg
 
Silvaire said:
Wait a minute, all he did was write down some numbers on a card. He didn’t say he adjusted anything. Or did I miss something?
Click to expand...
Writing down numbers on a card is maintenance, and therefore must be logged appropriately.
 
cgrab said:
Just a reminder for those that forgot there is another thing besides GPS in their planes for finding direction and want to make it right.
Click to expand...
I was wondering if the numbers were different than what the old card had? Thanks
 
Leavenworth is full of guys that were caught altering compass correction cards.
16isa0.jpg
 
MauleSkinner said:
Writing down numbers on a card is maintenance, and therefore must be logged appropriately.
Click to expand...
I don’t think so. Replacing the card is maintenance. I think you can write numbers on cards all day long without logging it. ;)
 
Salty said:
I don’t think so. Replacing the card is maintenance. I think you can write numbers on cards all day long without logging it. ;)
Click to expand...
you can, until you put the card in the aircraft. Then it must be logged and signed by an a&p
 
Completion of a Compass swing is maintenance, deal with as any maintenance
 
AKBill said:
I was wondering if the numbers were different than what the old card had? Thanks
Click to expand...

Some went up, some went down. I WILL NOT attach it to my airplane since I am only an owner/pilot and not an A&P (IA). I will keep it on my knee board so I can use it and actually fly safely.
 
I cannot find an entry in the 73 years of logs for a correction card so mine must be from 1947... who knows? if they are hunting me down to stick me with a violation for writing a few numbers down that stick in a little frame on the panel, I’m thinking I’m screwed in multiple ways because they obviously at that point are hunting to nail me for something.l if they are looking for that!

I think some of this stuff is way over inflated. Write it down and put it on the panel and fly and sleep well for God’s sake!
 
You must log in or register to reply here.
Back
Top