Artificial Horizon showing bank when level

[Raptor05121]

I have a SigmaTek artificial horizon and I have noticed during start-up idle, it will stay still and takes a few minutes to right itself during taxi. Pulling backup suction doesn't help. The worst part is it shows a consistent 2-3* left bank when straight and level. I'm wanting to start instrument training and I found an outfit called Aircraft Quality Instruments that overhauls gyros for $360. Has anyone used their service before? Seems like a decent price. Just gotta schedule my IFR check (another $345) before I can even start logging soup time.

[N6758N]

Bob Brandle (sp?) is the way to go for most instrument repairs, I forget who he works for though...someone here can chime in. 

[XXX]

13 minutes ago, Raptor05121 said:

I have a SigmaTek artificial horizon and I have noticed during start-up idle, it will stay still and takes a few minutes to right itself during taxi. Pulling backup suction doesn't help. The worst part is it shows a consistent 2-3* left bank when straight and level. I'm wanting to start instrument training and I found an outfit called Aircraft Quality Instruments that overhauls gyros for $360. Has anyone used their service before? Seems like a decent price. Just gotta schedule my IFR check (another $345) before I can even start logging soup time.

Try Naylors Instruments in Gainesville. They fixed my T&B coordinator in 3 days for $250. If they have one on the shelf you can trade out and won't have to wait.

http://www.naylorsinstrument.com/

[Raptor05121]

My IA just texted me about Naylors. On their models list I don't see SigmaTek anywhere :/

[Piloto]

Check the instrument panel leveling. If one of the panel shock mounts is broke it may tilt the panel. Cross check with the ball slip indicator.

José 

[PTK]

22 hours ago, Raptor05121 said:

...The worst part is it shows a consistent 2-3* left bank when straight and level....

Well, that's easy! Roll and hold a 2-3° right bank! 

[Raptor05121]

12 hours ago, PTK said:

Well, that's easy! Roll and hold a 2-3° right bank! 

That's not hard. I have to hold left pressure on my yoke to keep wings level. If I let go, it goes into a right bank

[Oldguy]

On 3/29/2017 at 11:07 AM, N6758N said:

Bob Brandle (sp?) is the way to go for most instrument repairs, I forget who he works for though...someone here can chime in. 

Ok, so very bad video of how fast a rebuilt AI by Bob Bramble spins up. Have to look quickly at it before startup or rewind and freeze. This is after 2 years of use. Sorry for the shaking - one hand on key, one one mixture. Camera in pocket until it starts.

Robert Bramble
Aerolab Aviation Services
www.aerolabaviation.com

FAA CRS#40RR239Y
8191 N Tamiami Trail
Hanger B-2
Sarasota, FL 34243
Ph: (913) 680-4169 

IMG_2435.mp4

[mooniac15u]

Is your AI attached to an autopilot?  If not you might want to think about putting those overhaul dollars towards a Garmin G5.

I realize that might not be within your budget range right now.  Just something to think about.

[Raptor05121]

I dont even have PC in my plane.

[smwash02]

I've used AQI for 4-5 instruments and warrantied one that ended up being my fault, but they took care of it anyways. I would use them again.

A couple things, though:

1) What's your vacuum pressure at idle?

2) If it's in the right range, is your vaccum gauge accurate? I had mine tested with a commercial gauge and an AutoZone one and found mine reads low by .5.

3) Which Gyro do you have? I run RC Allen Gyros and their manuals state: "All R.C. Allen vacuum gyros run off of 4.5 inch Hg, erect time is 3 minutes. "

4) I am bolding this because it's important. If your plane isn't rigged right, your gyro won't work right. If you have to hold in a correction on a calm day, your plane isn't flying properly. Your gyro expects level to be level. If your plane has to fly cattywampus to fly straight, you can't expect your gyro to do its job. It's also unsafe for IFR, in my opinion. You should get it re-rigged. Your gyro issue might go away and your plane will fly better and probably faster.

Best of luck.

Edited April 2, 2017 by smwash02

[takair]

Have you had any work done behind the panel?  Kinks or leaks in the lines can show similar symptoms, even with good vacuum. In fact, a kink will tend to show good vacuum. With a leak, it depends where it is, but the vacuum system can overcome a small leak.  The gyro however needs good airflow and the vacuum guage does not tell us that.  The tilt could be a separate problem....like Jose suggested, check the panel mounts.....they are often forgotten till they break.  2-3 degrees seems about right for that.