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-   -   Aerobatics vs Gyros (https://vansairforce.net/community/showthread.php?t=80285)

tomcostanza 12-21-2011 11:13 AM

Aerobatics vs Gyros
 
I read a Mid-Continent manual that advised turning off the gyro 5 minutes before doing aerobatics. I assume the 5 minutes is to let the gyro spin down. I have 3 gyros. I don't want to use 3 switches, but I'm willing to use one 3 pole switch. Any suggestions? Has anyone done this?

Best holiday wishes to all.

jbagley 12-21-2011 01:13 PM

I'm interested in any responses to this one.

I have a vacuum attitude indicator, vacuum DG and an electric turn and bank. The turn and bank can be turned off by a switch. I assume the vacuum gyros can be turned off somehow as well, but i'm not sure how. If your gyros are all electric, I would think a 3-pole switch would work just fine (check the current draw of the instruments vs switch capacity).

Rolls don't seem to bother the gyros much, but loops make the attitude indicator unhappy. YMMV.

flyinga 12-21-2011 01:50 PM

Something to think about: a three poll swtch introduces a single point of failure for all three gyros.

aerhed 12-21-2011 01:55 PM

On an 8 I built, I installed a 3/4" ball valve to cut the vacuum off. Its on the subpanel with an easy to reach lever.

jbagley 12-21-2011 02:11 PM

Quote:

Originally Posted by flyinga (Post 608275)
Something to think about: a three poll swtch introduces a single point of failure for all three gyros.

Good point. You could use some relays combined with a switch. If the relays are normally closed circuits with a switch to turn them off then you can have a single switch without a single point of failure.

The failure mode would be in the on position.

Though everyone has to find their own comfortable balance between simplicity and redundancy. It's generally, but not always, a trade-off.

jbagley 12-21-2011 02:14 PM

Quote:

Originally Posted by aerhed (Post 608277)
On an 8 I built, I installed a 3/4" ball valve to cut the vacuum off. Its on the subpanel with an easy to reach lever.

Thought about doing that, but I'm not sure if the back-pressure would damage the vacuum pump.

aerhed 12-21-2011 02:21 PM

It makes all the air go through the regulator. An alternative would be a 3 port valve with an inlet filter. Probably more better.


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