Gyros

[MXpilot1]

When I do aerobatics my attitude indicator tumbles. If I do it long enough, it starts to spin. I'm sure that if I keep this up I'm going to damage it and probably my heading indicator too. I'm thinking about installing a valve in the vacuum line so that I can shut off the vacuum prior to taking off. Then, when I finish with aerobatics, I can turn it back on. Anyone have any thoughts on this? I've noticed too that my vacuum gage is pegged out at maximum. I'm guessing that this could be damaging to the gyros as well. Are the regulators adjustable?

[Brian Denk]

I have vac driven AI and DG and the AI tumbles fairly randomly after plenty of looping and rolling over the past six years. It will work ok sometimes, then rolls over and plays dead other times. I'm now trying to decide on 1. remove entire vac system and gyros, or 2. have them overhauled and not fly acro anymore to keep them healthy longer. NOT!

I don't fly IFR so they're there for night ops, which I'm not flying nowadays either, so, they're mostly just eye candy and fill those big holes I drilled in the panel for them back in the crazy 90's when I built the thing.

The valve idea was discussed at great length long ago on the Matronics RV list and it was almost as hotly debated as the primer issue. Unless you have the mega buck military type gyros with positive caging mechanisms, your acro flying will eventually booger up the gyros. They may last years, they may die tomorrow. But banging them to the stops while spinning or at a stand still is not good for them. They're really not suited for such gyrations. With today's solid state glass attitude EFIS displays being offered by Blue Mountain, Dynon, and probably someday Walmart, I can see the days of vac or electric gyros in RV's being numbered. The money I would spend to overhaul my gyros would be better spent to replace them entirely, methinks.

It's rather hard to equip an RV for comfortable and safe IFR flying AND aerobatics. But, it's a lot easier today with the glass options. I guess we really just need to build TWO RV's...one with bare minimum VFR gauges to fling about willy nilly and a full house IFR/leather seats/wet bar/potty for traveling.

Brian Denk
RV8 N94BD

[Mel]

I had an electric attitude indicator. I caged it during aerobatics, but it still didn't like them. It began to take longer and longer to recover. I sold it and installed a Dynon D10 and never looked back. The mild aerobatics that I do don't bother the Dynon.
BTW. The guy I sold the electric attitude indicator to doesn't do acro and last I heard, it was still working fine.
Mel...DAR

[AlexPeterson]

See: http://www.home.earthlink.net/~alexpeterson/misc.htm

As Brian said, there were discussions on the Matronics list about whether or not gyros are better off running or stopped. Nonsense, a spinning gyro is going to see enormous forces, both in the axle bearings and in the gimbal bearings, when it ploughs into the stops. A stopped gyro will just think it is being shipped through the mail. Actually, aerobatics in these planes is amazingly gently - think about it. Hold a gyro in your hand and "fly" it through the aerobatic maneuvers you might do, and see how gentle it really is. Sure, the gimbal will bang around a bit. Then try it with the gyro spinning.

Alex P.

[gmcjetpilot]

Alex good point.

I always wondered about the wisdom of doing aerobatics with Gyros and than launching into solid IFR later with those same Gyros.

I concur with the Acro + Gyro = Writing large $checks$ to the Instrument shop. I know I went thru a few in my time. I like Mel now have a D10 EFIS.

G

[MarcoAviator]

Hi, I am new to the forum.

I have a (possibly) stupid and naive question: do you guys actually fly aerobatics with your RVs?

RV8s and RV4s I assume? What kind of manouvers have you been able to fly? How many Gs did you ever pull?

Thanks!

[John_RV4]

I'm wondering about the vor/ils indicators holding up to acro ? At $1500 or so, they must be something "special". Do they also suffer from acro ?

John

[MXpilot1]

I fly an RV6. It's no Pitts, but I can do good basic aerobatic manuvers in it. My engine doesn't have inverted fuel or oil systems so I am pretty much confined to positive G manuvers. Loops, rolls, cubans, immelmans. I haven't done snap rolls because they impart a lot of stress on the plane but it would surely do them fine. As was stated above, these are very gentle manuvers (not the snap roll) and I don't suspect they would have any detrimental effect on the elctronics. Since my earlier post i have added a valve to my vacuum line to shut off my gyros. The seem to spool back up fine. Will they survive? Only time will tell.