Best Horizon/attitude indicator system?

[brettt777]

What is the best attitude/horizon system to use in a semi-high performance aircraft (L-39)? The original gyro/ADI's, which was an excellent system, were removed and the existing system basically can't keep up with the airplane during manuevers.

[Splinter562]

Well, the questions I'd ask are:
1) How much are you really using the ADI when maneuvering?
2) How much money do you want to put into the airplane?

I fly aerobatics in Citabrias and Decathlons, so I don't have a gyro system.  If I did, I don't think I'd use it during aerobatics (infact, you'd probably want to keep the gyro caged anyway). So I'd try to first decide if it is even worth it to replace the ADI over laggy performance while maneuvering.

If you decide that you really want to replace it, then you've got two options. The cheapest (*relatively*) option would be to get a better steam gauge, which may help you a little. But any steam-gyro system you buy will have difficulty with aerobatics. If you really want to pour some money into the airplane you could go with one of the many EADIs on the market. A ring-laser gyro doesn't have the same limitations of a steam-gyro, so it'll keep up with aerobatics. The problem is that putting in a glass system is that the units are expensive, and it takes a significant amount of labor to wire it all up.

If you are looking at EADIs a few of the major manufacturers are:
Aspen
Sandel
Dynon
Blue Mountain

[Boss_BlueAngels]

Here ya go, the only attitude indicator I use anymore:

[Ivan]

@brett:
Go to a L39 importer and try to get an original system. I dont think you can get milspec (high-G AND areobatic rated) gyros in the regular market.
Only problem is that the original units are quite heavy

[brettt777]

@brett:
Go to a L39 importer and try to get an original system. I dont think you can get milspec (high-G AND areobatic rated) gyros in the regular market.
Only problem is that the original units are quite heavy

Actualy the company I work for is an L-39 importer, although none have been brought into the country in quite some time. We maintain about 70 of the 250-300 L-39s in North America so I am very familiar with the original Czech system. Idealy I would love to put that system back into the aircraft but even if I could gather all the components, all of the factory wiring has been removed. I was simply asking what is a suitable, like system to replace it with. The one in the A/C now (not sure what make it is, haven't looked yet) is the same type of system, more or less, but isn't suitable for aerobatics. I would love to install an EFIS/AHRS type of system like a nice Chelton but I don't think the owner will go for it although he certainly has the wallet to pay for it.

[DaveSims]

Most of our locals swear by Dynon, including a couple with highly aerobatic experimentals.  They aren't too high in price and seem to work quite nice.

[brettt777]

Dynon is one of the brands I am considering. The problem is finding one that will handle a 200 degree per second roll rate consistently. I wish I could just put the old Czech system back in but there is no room for it now. I found a few great units today from L3 that would work great; one of them is the back up horizon for an FA-18. But because they are milspec type stuff they cost as much as a small house.