So I'm in the midst of this avionics install and it occurs to me that I may not need my vertical card compass. I just bought two G5's (the AI and the HSI). I have the water compass up on the glare shield; do I need the vertical card compass?

Thanks in advance!

Jim

No

Never heard of a "water compass".
Is that a whiskey compass for drunks that are on the wagon?

Aside from that, not sure I understand the question.
Do you have a standard whiskey compass PLUS a vertical card compass?
Regs require only compass....
and that has nothing to do with your dual G5 installation.

hotrod180 wrote:Never heard of a "water compass".
Is that a whiskey compass for drunks that are on the wagon?

Aside from that, not sure I understand the question.
Do you have a standard whiskey compass PLUS a vertical card compass?
Regs require only compass....
and that has nothing to do with your dual G5 installation.

Yes - Whiskey compass. I thought it had to be supplemented by a second. The G5's have compass heading. My question was if that would satisfy the requirement?

No, the G 5 will not eliminate the need for a magnetic compass.

Either the whiskey compass OR the vertical card compass will fulfill that requirement, but only one or the other is required.

MTV

THANKS MTV!

mtv wrote: No, the G 5 will not eliminate the need for a magnetic compass.
Either the whiskey compass OR the vertical card compass will fulfill that requirement, but only one or the other is required.

That was my first reaction also, however, after some thought I'm not sure that's correct.
I decided to check the regs:

https://www.law.cornell.edu/cfr/text/14/91.205

FAR 91.205 (b)Visual-flight rules (day).
For VFR flight during the day, the following instruments and equipment are required:
(1) Airspeed indicator.
(2) Altimeter.
(3) Magnetic direction indicator.

The STC'd Garmin G5 HSI connects to a remote magnetometer, so it appears to meet this requirement.

Not so sure I'd get rid of my compass even if it was "legal." It was the first thing that was put in boats let alone airplanes. For me, the VCC is much more useful than the whisky. If your VCC is in the panel, you might think about moving it up to the windscreen as they tend not to work too well in the panel due to the interference of the black magic inside.

Read the STC. By the regs the G5 should also allow elimination of the turn coordinator, however the STC prohibits it (for now). That said, I would love clarification from them on what happens if your plane never required by by certification anyway. In any event check the STC and see if it gives you any guidance on the compass.

To echo Bigrenna, I'd leave the compass there either way. Even G1000-equipped aircraft still retain a mag compass, that tells me what I need to know about anything lesser in Garmin's line.

Thanks for the help guys! I think I'm going to ditch the VCC and keep the wet compass. I never look at the VCC anyway and I could use the Realestate!

Cheers!

Jim

hotrod180 wrote:

mtv wrote: No, the G 5 will not eliminate the need for a magnetic compass.
Either the whiskey compass OR the vertical card compass will fulfill that requirement, but only one or the other is required.

That was my first reaction also, however, after some thought I'm not sure that's correct.
I decided to check the regs:

https://www.law.cornell.edu/cfr/text/14/91.205

FAR 91.205 (b)Visual-flight rules (day).
For VFR flight during the day, the following instruments and equipment are required:
(1) Airspeed indicator.
(2) Altimeter.
(3) Magnetic direction indicator.

The STC'd Garmin G5 HSI connects to a remote magnetometer, so it appears to meet this requirement.

You may indeed be correct. The FAA has accepted SOME magnetometer equipped aircraft to operate without a conventional compass.

That said, as others have noted, the replacement of the compass would have to be authorized in the STC.

The advantage of a conventional compass is, of course, that it requires no electricity or other aircraft systems to function. If the lights go out, the compass may be all you have for navigation.

Been there.

MTV

mtv wrote:The advantage of a conventional compass is, of course, that it requires no electricity or other aircraft systems to function. If the lights go out, the compass may be all you have for navigation.

Been there.

MTV

I won’t argue with you there, but the disadvantage of the conventional compass is its sensitivity to EM interference.

If you’re truly looking to use your whisky compass as a power-out option - I’d swing it with the engine on, master off.

mtv wrote:.... The FAA has accepted SOME magnetometer equipped aircraft to operate without a conventional compass.
That said, as others have noted, the replacement of the compass would have to be authorized in the STC.
The advantage of a conventional compass is, of course, that it requires no electricity or other aircraft systems to function. If the lights go out, the compass may be all you have for navigation....

I agree, I wasn't so much condoning removal of the compass as pointing out that it might be legal to do so per the regs.
Personally I would keep it on board though.

My C180 had a vertical card compass mounted on the windshield,
when I shuffled the instruments around & came up with some room for it, I relocated it to the panel.
Tried 3 different sposts, I never could get it swung to where turning on the master / lights / radios / etc didn't drastically effect it.
I finally fucked up the adjustments by over-turning the screws,
and ended up buying a regular whisky compass and mounted it (guess where)..... to the windshield.

CamTom12 wrote:

mtv wrote:The advantage of a conventional compass is, of course, that it requires no electricity or other aircraft systems to function. If the lights go out, the compass may be all you have for navigation.

Been there.

MTV

I won’t argue with you there, but the disadvantage of the conventional compass is its sensitivity to EM interference.

If you’re truly looking to use your whisky compass as a power-out option - I’d swing it with the engine on, master off.

Well, in my case, it helps not to have a master....

MTV