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Aerobatic durable AI?

W

wickedsprint

Well Known Member
In looking at the threads, it seems quite a bit of you have fragged mechanical AIs from doing acro. I always assumed that the caged ones could survive this.

So with that, are there any mechanical gyros that can no kidding take acro abuse, or do they all have to be powered down and caged prior?

I also like the looks of the TruTrak ADI even if its operation is somewhat unconventional, provided it will help me keep the plane upright if I end up in the soup.

I'm also trying to keep this bugger as light as possible. Mission is strictly day VFR, no desire to fly at night, I might even skip the AI all together.
 
I don't know about mechanical ones, but at osh one of the certified companies (Ray Allen I think?) was demoing a new all digital AI for certified airplanes at a fairly affordable price (I think around $1200?). Seems like that would be the ticket for you, light, low current draw, and pretty bulletproof. Supposedly available around the end of the year I think.

I personally don't like the way the ADI "thinks" and how it reacts to acceleration and deceleration cues, but it's probably good enough for day/night VFR. I don't think i'd have it as a sole attitude gyro instrument in IFR, but thats not your mission so it'd be fine.
 
Most any mechanical gyro we can afford will not tolerate lots of aerobatics well at all. Caging is sort of a misnomer, because with a few exceptions the caging mechanism isn't permanent (meaning the gyro isn't permanently caged), it's used for re-setting the gyro after it's gone whacko...most of the caging mechanisms are spring loaded for temporary reset.

That being said, most of the EFISes will handle it quite well, so does the ADI from Trutrak (been there have that).

Stephen, do you or have you flown behind the ADI for many hours or in unusual attitudes? Just curious, because most people who have don't have much negative to say about it, and most of the comments like yours typically come from people who have not or are not actually flying behind it. Use it in a plane (not on the bench) and you'll see that it's unlikely you can confuse it, even after a number of consecutive Cuban 8's, loops, hammerheads, etc.... I'm sure it's not meant for an extra 300, but did anyone see the Red/Black Beech 18 doing aerobatics at OSH? That's one of Younkins birds which has an ADI in it, as do his other aerobatic steeds.

Anyway, the misnomer of "caging" gyros is just that. Short of leaving them disconnected and finding one that permanently cages, or finding one of the SUPER expensive 360 degree roll/pitch gyros, the mechanical gyros don't do well, but the ADI and most all the EFISes do.

My 2 cents as usual!

Cheers,
Stein
 
EFIS

EFIS, why not?

Are you going to fly IFR in a plane you have been thrashing your mechanical gyros?

I have tried it, about 10 years ago, in my IFR equip RV-4. It got to be real expensive.
 
Stein: Let me make sure I understand one of the things you said. I'm not flying yet, but I have two "attitude gyros" in my panel, one is an ADI II and the other is one of the new Castleberry (sold by Sporty's) electric AI. Do I understand it correctly that if I know I'm going up to do some serious acro for a few minutes, that I can switch the power off to my Castleberry (prior to start-up) and not damage it while maneuvering? Should I put a "power" switch in-line with it so I can protect it from tumbling, etc.?

Presumably then, I could switch it on after aerobatics and "cage/fast erect" it and go on about my business?

Regards,


Lee...
 
A lot of warbirds have old gyros in them that are of the "non-tumbling" variety, with no caging mechanism. Usually they are either Sperry's or Bendix J-8's that are 115V 400Hz electric. They tend to last a long time. I have a a few Sperry gyros that I picked up a few years ago in brand-new original packaging for $15/ea.
 
wickedsprint said:
I also like the looks of the TruTrak ADI even if its operation is somewhat unconventional, provided it will help me keep the plane upright if I end up in the soup.
Click to expand...

Two ways I have been able to trick one of these buggers in flight is to have it in a prolonged constant, non turning, constant altitude slip. It will eventually show wings level but all you have to do is look at the slip/skid ball and you can tell whats going on. The other is a straight and level high angle of attack for a prolonged period with no altitude change. It will eventually show level pitch attitude.

Even with these differences from a true AI, I would still use one for a backup attitude indicating device for IMC. The slip issue really is not an issue if you use the slip skid ball, as far as the pitch indication, you would have to be way behind the airplane to get into that situation along with disregarding your other instruments. These things react instantly to changes in bank, vertical speed changes and this is what will keep you out of trouble. If you got into some screwed up attitude that causes an error on this device, you can use the other instruments to help figure it out.
 
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Appreciate the replies, so it looks like I'll have to go solid state if I want an AI...literally all I care about is durability and bacon saving in inadvertant IMC...still on the fence about even installing one...but will likely cave since only ~$1200ish and < 1lb.
 
Tony,

Why not pick up a Dynon D10A EFIS?
EFISD10A-Header.gif


Granted they cost a bit more than the ~$1,200 you quoted but it gives you so many more features and will be a good building block for installing an auto pilot.
 
On your back with a Tru Trak...

I have 200 hours doing acro with my Tru Trak ADI with absolutely no issues.I tumbled my Sigma Tec gyro and T&B before buying the TT.
A great value and has an autopilot upgrade option. Installation is very easy and it works great!

Smokey
HR2
 
Strictly day VFR?

wickedsprint said:
Appreciate the replies, so it looks like I'll have to go solid state if I want an AI...literally all I care about is durability and bacon saving in inadvertant IMC...still on the fence about even installing one...but will likely cave since only ~$1200ish and < 1lb.
Click to expand...


I guess it depends on how "strictly" you want to be but my last airplane had no gyro at all and I flew 400 hours in it without issue in horribly rainy Western Oregon...

Best gyro we have is "looking out the window"

I would look at the cost of just having a Dynon D10A and avoiding having any mechanical instruments...Or even a D180 (I think) that has all your engine instruments as well.

It will save you weight and you'll only have to cut one whole in the entire panel, thus saving a lot of work too.


Probably not a cheap option though

Frank
 
frankh said:
I guess it depends on how "strictly" you want to be but my last airplane had no gyro at all and I flew 400 hours in it without issue in horribly rainy Western Oregon...

Best gyro we have is "looking out the window"
Click to expand...

True..............regarding VFR conditions and "looking out the window".

However, we've had a good share of accidents around here (mostly fatal), when whiteout conditions quickly occured for one reason or another.

L.Adamson --- RV6A
 
frankh said:
I guess it depends on how "strictly" you want to be but my last airplane had no gyro at all and I flew 400 hours in it without issue in horribly rainy Western Oregon...

Best gyro we have is "looking out the window"

I would look at the cost of just having a Dynon D10A and avoiding having any mechanical instruments...Or even a D180 (I think) that has all your engine instruments as well.

It will save you weight and you'll only have to cut one whole in the entire panel, thus saving a lot of work too.


Probably not a cheap option though

Frank
Click to expand...

Considered that idea, but don't want an expensive single point of failure to leave me stranded if the smoke escapes. I'll probably just get an autopilot since it will also save my bacon in IMC if I find myself there.
 
osxuser said:
I don't know about mechanical ones, but at osh one of the certified companies (Ray Allen I think?) was demoing a new all digital AI for certified airplanes at a fairly affordable price (I think around $1200?). Seems like that would be the ticket for you, light, low current draw, and pretty bulletproof. Supposedly available around the end of the year I think.

I personally don't like the way the ADI "thinks" and how it reacts to acceleration and deceleration cues, but it's probably good enough for day/night VFR. I don't think i'd have it as a sole attitude gyro instrument in IFR, but thats not your mission so it'd be fine.
Click to expand...

I use the Trutrak ADI as my primary IFR AI. I have never had a issue and have full confidence in it IMC. So far I have logged 27.6 hours actual IMC with my RV. I also do aerobatics and the ADI seems to cover just fine after a few minutes.

Steve
7A Flying + 2 years
 
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