Acrobatics limited by Gyros Question

[Webb]

Too late now to change panel. Another day and I will build a new panel. I have steam gauges and my gyros (AI and DG) are vac and don't have acage knob.

Don't know why I didn't think of it when I bought my gyros, but RV's have been know to do things besides fly from point A to B.

Did the search on acros and tumbling gyros but couldn't find it.

What, if any, acrobatics can be done without turning my gyros into expensive paperweights? I also fly IMC (a lot) and depend on them.

As always, experience counts!!!

[Jim Percy]

It's my understanding that aerobatics with the gyro caged can still cause damage. The only reasonably sure way to prevent damage is to have the gyro stopped. I have no experience with it, but could you install some sort of bypass valve in your vacuum system to shut them down entirely during aerobatics? Open the bypass, wait a few minutes while the gyros spool down, then yank away!

[rv7charlie]

I was a partner in a 200 hp Globe Swift for a couple of years. My partner, who owned the plane for probably 10 years before I became a partner, used the plane as his 'commuter', flying in all kinds of weather to his airline job. He also flew airshows in the plane and I learned acro in it, so the instruments got regular workouts. I'd guess that it had at least 200 hrs of acro on it, and about that many hours in actual IFR conditions.

The gyros were never 'caged' when doing acro. The only thing unusual about them that I'm aware of was that he told me the attitude indicator was 'non-tumbling', whatever that means. Over about 1500 hours & a dozen years, the only failures were vac pumps.

Charlie
Slobovia Outernational Airport
flying -4, -7 canopy work

[MXpilot1]

I have a valve under the panel in the vacuum line that shuts off the vacuum. If I know I'm going to do acro, I'll shut off the vacuum before I take off. If I'm already flying, I'll shut off the vacuum and wait a while fot the gyros to spool down.

[Webb]

Originally Posted by MXpilot1

I have a valve under the panel in the vacuum line that shuts off the vacuum. If I know I'm going to do acro, I'll shut off the vacuum before I take off. If I'm already flying, I'll shut off the vacuum and wait a while fot the gyros to spool down.

Thanks - Sounds like a good solution. I'll install later so I can enjoy acrobatics when I'm am "one with the airplane - Master Yoda". In the meantime, I'll just get good and familiar with my RV's flying characterists during the first several months.

The valve.....how installed? Bypass, shut off, how does it work and where is it located....etc.....

[Mel]

Keep in mind that without the gyros spinning, unless they are caged, they will still bang against the stops during acro. Better than tumbling, but still not particularly good for them.

[frankh]

you cage them and shut off the vacuum?

My Dynon gets real confused but it never seems to be permanently concussed...Unlike the pilot..

[Webb]

Originally Posted by frankh

you cage them and shut off the vacuum?

My Dynon gets real confused but it never seems to be permanently concussed...Unlike the pilot..

Frank - Are you confused often? Are you sure that the ETOH is only in the gas you're flying (LOL)?

Just kidding. I talked with one of my buds at the airport today. His suggestion was to disconnect the vacuum line if you are planning acrobatics.

He did comment that an occasional tumble wasn't a big deal but over time will do it's damage. It took him 300 hours to do his in and he rolled and looped every time he flew his 8. I wonder how many tumbles he means?

[SteinAir]

Hi Webb,

This is kind of a "catch 22" as far as safe acro goes in regards to gyros.
Rolls are usually no issue with Attitude Gyros, but will kill the DG's. DG's will handle loops ok, but that causes the attitude gyro to go nuts....soooo, juts go have fun!

Also, disconnecting the vacuum has been tested/tried and has shown over the years to net almost the same long term reliability as having them powered up - a'la what Mel said.

Next, in regards to "caging" a gryo....I've posted this many times, but with the gyros we all use, they don't permanently cage or lock. People seem to think the little knob permanently locks the gyros, when in fact with the typical gyros we use it does no such thing. The caging knob is for re-erecting a tumbled/off kilter gyro and is spring loaded. You pull it and it re-erects the gyro to level (should be done when flying level). Other than some very high end, every expensive gyros, the "caging" know is nothing more than a "reset" knob. I had very expensive gyros in my old RV6 (and the attitude was "cageable", but again, somewhat of a misnomer).

I say fly them until they are toast, then rip them out and buy an EFIS! Not much you can do to avoid it except avoid acro - which is a sin if you own an RV!

My 2 cents as usual!

Cheers,
Stein.

BTW, I think mine took about the same amount of time to die...and rolls are required on every RV flight in my plane!

[Mel]

Originally Posted by SteinAir

Next, in regards to "caging" a gryo....I've posted this many times, but with the gyros we all use, they don't permanently cage or lock. People seem to think the little knob permanently locks the gyros, when in fact with the typical gyros we use it does no such thing. The caging knob is for re-erecting a tumbled/off kilter gyro and is spring loaded. You pull it and it re-erects the gyro to level (should be done when flying level).
Cheers,
Stein.

BTW, I think mine took about the same amount of time to die...and rolls are required on every RV flight in my plane!

When I had an electric attitude gyro in my -6 I would remove power, pull out the cage knob an insert a spacer that I made to hold the knob in the caged position. This seemed to work fine.
Later I replaced it with a Dynon...problem solved!