What Constitutes a Compass ?????

[Ron5335]

No doubt somewhere it is written that every aircraft must have a compass but I cannot find where.

 

My problem is that I want to install a more aerodynamic canopy but to do so I would have to remove the fluid compass on top of the dash & because of all the other installed gauges, I cannot fit an in-dash vertical card type.

 

I have a GPS that has a compass display screen, plus I also have a small back up GPS that also has a compass display and not to mention the smart phone in my pocket that also has a compass feature.

 

Can anyone enlighten me on the actual requirements and whether electronic compasses are recognised as being suitable.

 

 

[silvercity]

Off topic Ron but what are your thoughts on the Super Diamond?

 

 

[eightyknots]

I think it has to be a magnetic compass so a cellular phone won't do.

 

 

[ruffasguts]

No doubt somewhere it is written that every aircraft must have a compass but I cannot find where.My problem is that I want to install a more aerodynamic canopy but to do so I would have to remove the fluid compass on top of the dash & because of all the other installed gauges, I cannot fit an in-dash vertical card type.

 

I have a GPS that has a compass display screen, plus I also have a small back up GPS that also has a compass display and not to mention the smart phone in my pocket that also has a compass feature.

 

Can anyone enlighten me on the actual requirements and whether electronic compasses are recognised as being suitable.

refer the following

 

Civil Aviation Order 20.18 - Aircraft equipment - Basic operational requirements (02/12/2004)

 

magnetic compass required

 

Mick W

 

 

[djpacro]

CAO 20.18 http://www.comlaw.gov.au/Details/F2013C00121 requires a magnetic compass.

 

(took me 10 mins to find the link!)

 

 

[eightyknots]

CAO 20.18 http://www.comlaw.gov.au/Details/F2013C00121 requires a magnetic compass.(took me 10 mins to find the link!)

Magnetic compasses don't have battery failures.

 

 

[Guest Maj Millard]

The old magnetic compass is there when everything else has failed !....bit like an ejection seat I suppose.....Maj...

 

 

[Herm]

So the one in my Bata Scout Shoe should be fine then?

 

 

[rgmwa]

There could be an exemption from the need to have a magnetic compass depending on your aircraft:

 

3A.3 Paragraph 3.4 does not apply to any other aircraft that operates under the V.F.R.:

 

(a) being an aircraft for which a current certificate of airworthiness as an LSA has

 

been issued; or

 

(b) being an aircraft for which an experimental certificate has been issued under

 

paragraph 21.191 (g), (h) or (j) or an LSA for which an experimental certificate has

 

been issued under paragraph 21.191 (k), of CASR 1998;

 

if equipment is carried that provides a pilot with the same information that would be

 

obtained by compliance with the requirements of Appendix I for operations by day, or

 

Appendix IV if approved for operations by night.

 

rgmwa

 

 

[Guest Maj Millard]

There's a good compass function available on OzRunways....fully CASA approved!!!!.............

 

 

[djpacro]

OzRunways is only approved as a provider of documents http://www.recreationalflying.com/threads/ozrunway-on-mini-ipad.64231/page-3#post-302217

 

 

[old man emu]

Why not go to a good camping equipment store and buy a good quality prismatic compass? You can carry it in a map pocket in the cockpit for reference if the GPS fails. The Regs only say that you have to carry a magnetic compass. They don't say anything about referring to it during Day VFR flight.

 

You will still have to do a compass swing to work out the compass' deviation and to make a com[ass deviation card.

 

OME

 

 

[facthunter]

A proper magnetic compass would have to be swung and corrected and a deviation card installed. Somewhere there would be a table of tolerences allowed. Nev

 

 

[djpacro]

But this bit states that the compass is to be fitted, not just carried.

 

10.1A A private or aerial work aircraft must not be operated:(a) under the V.F.R., unless:

(i) all instruments and equipment required to be fitted to the aircraft under subsection 3 are serviceable before take-off; or

One day, in the fullness of time, the new Part 91 will be issued and things will be much clearer. In the meantime, depending on the certification approval for the particular aircraft, trawl through the regulations. eg Part 21 calls up the USA Part 23 for the airplanes that I fly and that requires a magnetic compass to be installed in the machine and goes on to specify installation requirements and wording of the placard.

[Ron5335]

Thanks Everyone for your input.

 

I knew someone would come and rain on my parade.

 

 

[Ron5335]

Silvercity,

 

I am totally satisfied with the Super Diamond.

 

Small, roomy, fast (110kt +), carries 5 hours fuel.

 

Strong as (Has the same wing as the Sierra and that was tested to 14G) But the Super Diamond wing is shorter so it's stronger again.

 

 

[Yenn]

rgmwa.

 

I think the quote you give does not apply to compasses usually, but is more for the electronic altimeter and ASI instruments. I thought I would have to use it for my Flight 2 MGL instrument, but I was able to get it certified by an avionics workshop. It only took money to get it done.

 

 

[Downunder]

My "24"reg aircraft did not come with mag compass. Electronic only.

 

 

[old man emu]

A proper magnetic compass would have to be swung and corrected and a deviation card installed. Somewhere there would be a table of tolerences allowed. Nev

The only real correction a compass needs is to be corrected for Northern or Southern Hemisphere dip in the Earth's magnetic field. Swinging the compass provides the data to produce a deviation card. As long as the data is good. it doesn't matter if the compass is consistently one or two degrees off, or if it is 10 - 15 degrees off all the time. As long as the pilot can use the information provided by the compass to follow a planned course, it doesn't matter how far off actual it is.

 

How would you define "fitted" other than its being in the same location every time it has to be used. You can always put a bit of Velcro on a level surface and another on the back of the compass and secure it that way.

 

OME

 

 

[facthunter]

OME, I would have thought there are stipulated limits to several types of error of readings. A compass installed into an aeroplane is subject to magnetic effects in a particular aircraft and it is done with electrical power ON. Some aircraft have a remote flux valve but are still magnetic compass(es). Ie they give you a HDG (M) even though the indication need electrical power to operate it. ( Vertical presentation). I can't recall any certified installation without a deviation card. Nev

 

 

[rgmwa]

rgmwa.I think the quote you give does not apply to compasses usually, but is more for the electronic altimeter and ASI instruments. I thought I would have to use it for my Flight 2 MGL instrument, but I was able to get it certified by an avionics workshop. It only took money to get it done.

I don't know Yenn. Para 3.4 and Appendix I seem pretty straightforward, and the list in Appendix I specifically includes a magnetic compass along with ASI, Alt and clock. As I read it, none of these instruments are required if your plane complies with 3A.3, provided you have alternative means of obtaining the required information. Still, I wonder whether a sundial would qualify as an acceptable timepiece and whether a tape measure would be OK to check your height with. I guess the onus is on you to convince whoever assesses these things that your alternative instruments will reliably provide the same information as the listed instruments.

 

rgmwa

 

 

[frank marriott]

Remember what was allowed under previous conditions may well be rejected with the CASA overview now happening.

 

Personally I would not fly an aircraft without a magnetic compass, or how do you check that whatever wis bang device you are using is accurate. I still check a fully certified HSI against the magnetic compas as part of preflight checks. Maybe if you are only flying around the block it is not important but if you are going to do some serious nav over some distance then knowing the information is correct is important.

 

Just my opinion, not interested in what maybe or maybe not acceptable [or legal] - I like to KNOW the information I will be using is good information.

 

 

[Ron5335]

rgmwa

 

3A.3 Paragraph 3.4 does not apply to any other aircraft that operates under the V.F.R.: ( This is the section that leads to the requirement of a Magnetic Compass)

 

(a) being an aircraft for which a current certificate of airworthiness as an LSA has been issued; or

 

(b) being an aircraft for which an experimental certificate has been issued under paragraph 21.191 (g), (h) or (j) or an LSA for which an experimental certificate has been issued under paragraph 21.191 (k), of CASR 1998;

 

if equipment is carried that provides a pilot with the same information that would be obtained by compliance with the requirements of Appendix I for operations by day, or Appendix IV if approved for operations by night. (Appendix 1 states Magnetic Compass)

 

• Does an RAA Registered (19) fall into the category mentioned in para (b) ?
   
   
  
• If so, then the Bata Scout Compass would be allowed.
   
   
  

 

 

 

 

[djpacro]

How would you define "fitted" other than its being in the same location every time it has to be used. You can always put a bit of Velcro on a level surface and another on the back of the compass and secure it that way.

Yep, that CAO is quite vague. The engineering regs are quite clear so if it is FAR 23 certified then fitted means the installation is approved as part of the type certification and the thing has to be in the aeroplane. As for fitting with Velcro, sure you can do that but it still needs to have engineering approval per Part 21 of the regs. (And, if it is an LSA, then the manufacturer also has to approve the mod.) Somewhere online is an airworthiness bulletin regarding fitment of equipment with Velcro.Getting more off topic: I was with a flying school operating a fleet of aircraft, some used to appear without a compass deviation card per maintenance regs which permitted that if the deviation was within certain limits. Therefore it did not conform to FAR 23 and therefore Part 21 regs. More importantly, compass deviation cards can get lost so if an aeroplane doesn't have one the pilot doesn't know if it was meant to not have one or whether it was lost and has a large deviation. I agree, doesn't matter as the effect is the same as unforecast wind for anyone still using the compass. This next bit should be in the spelling thread: Interesting that the school gave all their students a checklist which required them to confirm that the deviation card was present as part of the daily inspection - not one student snagged an aeroplane.

 

 

[rgmwa]

rgmwa

• Does an RAA Registered (19) fall into the category mentioned in para (b) ?
   
   
  
• If so, then the Bata Scout Compass would be allowed.
   
   
  

Just out of interest, I looked up CASR 21.191. Here are the relevant bits regarding eligible aircraft types in the previous quote:

 

21.191 Experimental certificates

 

An experimental certificate may be issued for one or more of the following purposes:

 

(g) operating an amateur‑built aircraft: that is an aircraft the major portion of which has been fabricated and assembled by a person who undertook the construction project solely for the person’s own education or recreation;

 

(h) operating a kit‑built aircraft: that is an aircraft in the primary category that meets the criteria of paragraph 21.024(1)(a) and that was assembled by a person from a kit manufactured by the holder of a production certificate for that kit, without the supervision and quality control of the production certificate holder under subregulation 21.184(1);

 

(j) operating a light sport aircraft that:

 

(i) has been assembled from a kit in relation to which the applicant can give the information, statement and documents required by paragraph 21.193(e); and

 

(ii) has been assembled in accordance with the kit manufacturer’s instructions for assembling the aircraft; and

 

(iii) is of the same make and model as a production aircraft covered by regulation 21.186 that has been issued with a special certificate of airworthiness;

 

(k) operating any other light sport aircraft covered by regulation 21.186 for which a special certificate of airworthiness for light sport aircraft, or another document of similar effect under a law of a Contracting State, has been issued.

 

So if your aircraft is flying under an experimental certificate I think the answer to your question is `yes'. My kit aircraft comes under 21.191(g), and has a glass panel so I don't believe I need a backup magnetic compass.

 

Even so, I've put one in, ... err......plus an Alt, ASI and clock .... just to be on the safe side.

 

 

rgmwa