imwithtuxedo
Pre-takeoff checklist
Is a compass deviation card required equipment for VFR flights? If so, can someone point me to the applicable FAR?
Compass deviation card required for VFR flight?
- Thread starter imwithtuxedo
- Start date
Checkout_my_Six
Touchdown! Greaser!
well....do you have a "Magnetic direction indicator"? That usually is a magnetic compass.....and it requires a deviation card for accuracy.
ateamer
Pattern Altitude
23.1547 no longer exists. Part 23 was entirely rewritten; everything in it was superceded in 2017.
Last edited:
Checkout_my_Six
Touchdown! Greaser!
oh well....lingering is a problem.
ateamer
Pattern Altitude
oh well....lingering is a problem.
D’oh! Thanks for catching that.
I will linger a little longer.
imwithtuxedo
Pre-takeoff checklist
So, are you saying 14 CFR 23.1547 no longer exists and a compass deviation card is no longer required, or is the current in effect Section 23.1547 what we go by for compass card deviations?
§ 23.1547 Magnetic direction indicator.
(a) A placard meeting the requirements of this section must be installed on or near the magnetic direction indicator.
(b) The placard must show the calibration of the instrument in level flight with the engines operating.
(c) The placard must state whether the calibration was made with radio receivers on or off.
(d) Each calibration reading must be in terms of magnetic headings in not more than 30 degree increments.
(e) If a magnetic nonstabilized direction indicator can have a deviation of more than 10 degrees caused by the operation of electrical equipment, the placard must state which electrical loads, or combination of loads, would cause a deviation of more than 10 degrees when turned on.
dmspilot
Final Approach
- Joined
- Oct 20, 2006
- Messages
- 6,180
- Display Name
Display name:
DISPLAY NAME
The regulation that existed at the time the aircraft received type certification is what matters. Part 23 and CAR 3 both have required the deviation card.
imwithtuxedo
Pre-takeoff checklist
I've got a 1970 Cherokee 180E
ateamer
Pattern Altitude
Preface: Not trying to argue here, but genuinely looking to learn. This is a fun discussion.
As best I can see, 23.1547 does not exist. It was deleted from Part 23 when the rewrite took effect. The current version of the FARs starts with .2000, except for three subparts that were retained, .1547 not being one of them.
Thinking further, Part 23 applies to certification standards, and guides the manufacturer rather than the pilot. The pilot’s equipment regulations are part of Part 91, which says the AFM and/or placards and markings have to be complied with.
I figure that it will come down to what the AFM and placards say as to whether a compass deviation card is required.
Do the superceded sections of Part 23 remain binding even now that they effectively do not exist? I didn’t see a subpart stating them to remain in effect.
None of this is to say that it’s not just good practice to keep a current deviation card.
As best I can see, 23.1547 does not exist. It was deleted from Part 23 when the rewrite took effect. The current version of the FARs starts with .2000, except for three subparts that were retained, .1547 not being one of them.
Thinking further, Part 23 applies to certification standards, and guides the manufacturer rather than the pilot. The pilot’s equipment regulations are part of Part 91, which says the AFM and/or placards and markings have to be complied with.
I figure that it will come down to what the AFM and placards say as to whether a compass deviation card is required.
Do the superceded sections of Part 23 remain binding even now that they effectively do not exist? I didn’t see a subpart stating them to remain in effect.
None of this is to say that it’s not just good practice to keep a current deviation card.
dmspilot
Final Approach
- Joined
- Oct 20, 2006
- Messages
- 6,180
- Display Name
Display name:
DISPLAY NAME
The aircraft cannot be missing equipment that was required for type certification. 91.213(d)(2)(i).
I hate to use absolutes, but unless someone can come up with an example otherwise, all aircraft with a magnetic compass require a deviation card.
ateamer
Pattern Altitude
Boom! And there it is - there was a suspicion I was missing something simple, and that was it.
SkyDog58
Ejection Handle Pulled
- Joined
- Jun 11, 2015
- Messages
- 14,600
- Location
- My own special place.
- Display Name
Display name:
Canis Non Grata
Correct. And to expand on that a bit, one must also remember that an aircraft must be maintained in an airworthy condition. And the definition of airworthy includes conformance to its type design. And its type design is dependent on the certification standards in effect when it was certified.
MauleSkinner
Touchdown! Greaser!
...which brings up another question.
If an aircraft is certificated under the current version of Part 23, it sounds to me like the requirement for a compass card would fall under the “consensus standards”. How would one find our what those consensus standards are?
MauleSkinner
Touchdown! Greaser!
And to add just a bit more information, note that the historical versions of these regulations are accessible through the FAA website.
Yes. The "new" Part 23 is only for new model aircraft certified today. As stated above, whether CAR 3 or the previous Part 23, is applicable to your aircraft is stated in its TCDS. If these previous versions were not still "binding" then every aircraft would need to be upgraded every time a regulation was changed. And as a side FYI, every new Cessna or Piper manufactured today is done under the older Part 23 or CAR 3 as the initial model certification was done back then. So, the compass correction card is still required under the 23.1547.
There are several conversion lists out there. Here is one below. For Part 23.1547 mentioned above it would be in AC 23-8.
https://www.faa.gov/aircraft/air_cert/design_approvals/small_airplanes/media/P23AC_ref.pdf
imwithtuxedo
Pre-takeoff checklist
I'll get my compass deviation card calibrated and installed. Thanks for the informative discussion.
Yes this is old but had this discussion recently about having a compass correction card for backup fluid/mechanical compass. “It is illegal to fly without it.” Humbug!
Our plane has an Aspen EFD 1000 Pro (not Max) which is primary. A mechanical, fluid filled compass is required to be there as a backup. But the old regulation requiring it was retired. But if it is listed in the TCDS then it is required equipment and muat comply with rega in effect at that time, I was eventually but reluctantly convinced to have it recreated by an A&P.
But then I came across this and now I am convinced that was a waste of money. What do you all think?
https://www.faa.gov/documentLibrary/media/Order/FAA_Order_8110.121.pdf
Our plane has an Aspen EFD 1000 Pro (not Max) which is primary. A mechanical, fluid filled compass is required to be there as a backup. But the old regulation requiring it was retired. But if it is listed in the TCDS then it is required equipment and muat comply with rega in effect at that time, I was eventually but reluctantly convinced to have it recreated by an A&P.
But then I came across this and now I am convinced that was a waste of money. What do you all think?
https://www.faa.gov/documentLibrary/media/Order/FAA_Order_8110.121.pdf
- TCDS. Consistent with 14 CFR, a TCDS is part of a product’s type certificate (TC). A TCDS is a summary of the product’s type design. It is used primarily by authorized persons during initial or recurrent issuance of a Standard Airworthiness Certificate. It is neither a regulation, a maintenance requirements document, or a flight manual document. As such, for aircraft holding a valid and current airworthiness certificate, a TCDS should not be used as a sole source to determine what maintenance is required or what the flight operations requirements are. Any language on a TCDS, by itself, is not regulatory and is simply not enforceable.
- TCDS Notes. TCDS notes are intended primarily to provide information on the various requirements for issuing an airworthiness certificate as well as the type and location of various technical documents used to operate and maintain the product. Some OEM’s have placed mandatory language such as "shall," "must," and "will" on their TCDS that imply that compliance with TCDS notes is mandatory. However, in the absence of regulatory language, or an AD that makes such TCDS notes mandatory, compliance with such notes is not mandatory. It would mean that FAA regulations effectively authorize OEMs to issue "substantive rules," i.e., it would enable an OEM to impose legal requirements on the public that differ from the 14 CFR requirements. This would be objectionable for two reasons. First, the FAA does not have the
dmspilot
Final Approach
- Joined
- Oct 20, 2006
- Messages
- 6,180
- Display Name
Display name:
DISPLAY NAME
What do you think? I am confused how this would be seen as evidence that you don't need a compass. What argument are you trying to make?
Last edited:
guest user
Cleared for Takeoff
- Joined
- Dec 16, 2021
- Messages
- 1,002
- Display Name
Display name:
just passing through
@Stigmon I believe you're misunderstanding the argument here. The argument is not "You require a compass deviation card because of the TCDS", but rather that "The TCDS tells you what regulations are required to be complied with".
The rebuttal you're trying to make seems to revolve around the FAA saying that the TCDS "is neither a regulation, a maintenance requirements document, or a flight manual document." and thus you are not REQUIRED to follow the TCDS.
This may be valid if the TCDS were the only basis for requiring a compass card. However, it is not. The magnetic direction indicator is required by FAR.
Per FAR 91.205:
So, we see that a magnetic direction indicator is required for all flights (read lower and you'll see that VFR day is just the starting point for the other categories)
Now we move on to what was required at the time of type certification. We have to look at what WAS not IS. This is obvious, or (as has been pointed out above) we'd have to updated every airplane every time a certification requirement is updated. So now we go to what was a requirement for a long time (until 2017, as pointed out above):
To recap:
1) Magnetic direction indicator (compass) is required even to this day by FAR 91.205
2) Compass card is required by most aircraft unless TYPE CERTIFIED in the last very few years. (TCDS is used to determine what year the 23.1547 was complied with)
Your only legitimate argument would be that when TYPE CERTIFIED your aircraft was not required to meet the above 23.1547 on the date specified by the TCDS.
Hope this helps.
The rebuttal you're trying to make seems to revolve around the FAA saying that the TCDS "is neither a regulation, a maintenance requirements document, or a flight manual document." and thus you are not REQUIRED to follow the TCDS.
This may be valid if the TCDS were the only basis for requiring a compass card. However, it is not. The magnetic direction indicator is required by FAR.
Per FAR 91.205:
So, we see that a magnetic direction indicator is required for all flights (read lower and you'll see that VFR day is just the starting point for the other categories)
Now we move on to what was required at the time of type certification. We have to look at what WAS not IS. This is obvious, or (as has been pointed out above) we'd have to updated every airplane every time a certification requirement is updated. So now we go to what was a requirement for a long time (until 2017, as pointed out above):
--------------------
To recap:
1) Magnetic direction indicator (compass) is required even to this day by FAR 91.205
2) Compass card is required by most aircraft unless TYPE CERTIFIED in the last very few years. (TCDS is used to determine what year the 23.1547 was complied with)
Your only legitimate argument would be that when TYPE CERTIFIED your aircraft was not required to meet the above 23.1547 on the date specified by the TCDS.
Hope this helps.
40YearDream
Pre-takeoff checklist
So, a compass correction card is generally required. But, does it have to be readable? I've yet to see one that was (without a magnifying glass)
Mongoose Aviator
Line Up and Wait
Does your Aspen HSI also have a compass card? Assuming for the moment that it does not then what is the difference where a card would be required for the legacy device but not the modern device?
- Joined
- Apr 23, 2013
- Messages
- 6,672
- Display Name
Display name:
3G
Why would it? It’s self correcting at start up.
Dana
Final Approach
Yeah, I've had some that were so faded they were pretty much unreadable. But I fly experimentals; not only is a compass card not required, the compass itself is not required.
But ±5° is more than adequate to verify the highway I'm following is going in the right direction.
MauleSkinner
Touchdown! Greaser!
Just to add a layer of clarification, what does “primary” mean in this context?
MauleSkinner
Touchdown! Greaser!
If it isn’t readable it is inoperative, and we’re back to 91.213.
Hmmmmm.... y’know, now that I think about it, every card I’ve seen looked something like this:
I don’t recall seeing one that stated whether the radio receivers were on or off. I’m sure some do, but it seems uncommon, though the reg seems to require it.
I don’t recall seeing one that stated whether the radio receivers were on or off. I’m sure some do, but it seems uncommon, though the reg seems to require it.
Order 8110.121 specifically addressed the notes section of the TCDS as some OEMs were using it to predicate maintenance which is not legal. The TCDS is still a valid document and is only a summary of the type design, etc.
To add to the above, Part 23 was updated vs retired. Just as CAR 3 is still valid so is the previous version of Part 23 all of which require the correction card.
There's no official format for the cards so there will be wide variance. Regardless, the process to swing the compass is same.
Yes. Any required marking, placard, etc. is required to be legible. There is various guidance on this buried in several documents.
MauleSkinner
Touchdown! Greaser!
Invisible ink. You pee on it to make the ink visible.
MauleSkinner
Touchdown! Greaser!
Spoken like someone who won’t leave the airport without redundant GPS systems.
(Europe is pretty easy to find without an accurate compass card…err a few degrees to the right, and when you get to Africa, turn left.)
Doc Holliday
En-Route
People make this so much harder than it actually is.
40YearDream
Pre-takeoff checklist
Depends on how much range you've got - an extra 20 - 30 hours of reserve, and Europe would be no problem!
The Aspen EFD is your compass. It replaces the "by TCDS required magnetic direction finder." But because it can fail, it requires a backup compass. It is this that is the crux of the question.
As noted above and with the exception of flying across the Atlantic, the compass correction card, is likely never going to be "needed." Even if the compass is off by 5-9 degrees and here we go ...your ipad failed, your smartphone failed, the Aspen EFD failed, and you had no light in the cockpit (never mind how you are going to read the compass), ...then it's unlikely that the compass deviations would have a big bearing (pun intended) on your trip back to mother earth to deal with all the other issues.
Even if it were installed, I find it hard to imagine that anyone would consider the deviations if they are steering in an emergency, by the compass. So many other things would be on that pilots mind. And again, the errors in the compass would be the least of their problems for the relatively few miles they would fly to get to an airport and land. Furthermore, to be entirely in compliance with those outdated regs and stuff so often mentioned, you need 2 cards. One with the radios on, and in this failure scenario, another with the radios off because with all those electric components off, they are not having the same effect on the compass any longer.
Again, if it was the Atlantic I would have a manual compass in addition to a correction card...
That's the funny thing. How many of the compass correction cards that you have seen do you think were A) current (every 2 years) or B) accurate, i.e., updated after installation of some new electronics like that GNS430 that was swapped out for a GTN 650 and C) that corrects for the iPad attached to the yoke, the cables running all over the panel to charge all sorts of things, the Sport or InReach you have (and which also have compasses), or the stratus you use...
To me the compass correction card is simply ludicrous and to spend money updating it (or 2 of them; radios on/off) to be "legal" is humbug.
If you took that card, wrote something on it that was illegible or wrote nothing it wouldn't be an issue. We had a pilot who's IFR instructor said it was required equipment. We ended up having our IA make one and it took 30-45 minutes but to me it seems antiquated and unnecessary ...unless you are crossing the Atlantic.
FYI: there is no requirement for a 2 year check and rechecking the mag compass after installation of new equipment is part of the mx process. As needing 2 cards, thats also not required depending on several situations. As mentioned above maintaining a mag compass is about as simple as it gets.
MauleSkinner
Touchdown! Greaser!
Since “clarification” was my goal, let’s clarify…
A. Choose not to fly without multiple backups,
B. Choose not to fly more than a “relatively few miles” from somewhere you could land without any electronic devices, and/or
C. Choose not to be proficient enough to apply compass deviations in an emergency
has absolutely no bearing on certification standards.
No, it is not the “Magnetic direction indicator” required by 23.1547 (or equivalent) or 91.205. (The TCDS doesn’t require it, it simply points you to the certification regs that do.) The Aspen EFD is an attitude/heading reference system that could replace the “Gyroscopic pitch and bank indicator (artificial horizon)” and “Gyroscopic direction indicator (directional gyro or equivalent)” required by 91.205 for instrument flight. I say “could” because, although it probably does, I haven’t been able to find that specific documentation on the EFD 1000. “Primary” is not verbiage that I can find anywhere as it directly applies, but yes, most people primarily use their 6-pack flight instruments or the equivalent when they fly.
A magnetic direction indicator is required for all certificated airplanes, including those that have gyros, because, yes, among other things, the gyros could fail.
The fact that you:
A. Choose not to fly without multiple backups,
B. Choose not to fly more than a “relatively few miles” from somewhere you could land without any electronic devices, and/or
C. Choose not to be proficient enough to apply compass deviations in an emergency
has absolutely no bearing on certification standards.
This, again, just comes down to how accurately you choose to fly. In airplanes with an unslaved directional gyro, Radios ON becomes very important. But if you’re only concerned about the loss of electrical scenario, Radios OFF should be fine. You might even want to have one for no ship’s electrical, but your iPad on the yoke (or wherever you keep it). The regs don’t specify which configuration(s) are required, only that you be able to determine for which configuration(s) the compass card applies.
Last edited:
Mongoose Aviator
Line Up and Wait
fwiw, my POH under the Optional Equipment, Windshield Heating Installation has the following note:
"An additional compass deviation card is required with this installation. This card should indicate corrected readings with windshield heat and radios on."
"An additional compass deviation card is required with this installation. This card should indicate corrected readings with windshield heat and radios on."
Plano Pilot
Line Up and Wait
The deviation card on the Falcon 20's I flew said something like Windshield Heat must be off. Anytime the heat was supplied to the windshields the whisky compass showed one heading, 270 degrees if I remember correctly. I believe the KA's and Sabre were the same.