Failure of Vertical Gyro

[schrambow]

Just thought i would share my failure to help any others out there with older equipment if it happens to them in the future. 
This applies to Non-G600 TXi birds, but to the ones with older Collins vertical gyro's.  Our bird was down for many months due to lead times on new fuel cells.  We got her back in the air recently and had a nice trip out to Salt Lake City area.
Almost had tears in my eyes as i absolutely love this machine and missed it so much while it was down. Had a perfect flight out to the west and completed the mission, can't believe how a dry mid 90's feels cool compared to our mid 80's high humidity. Anyways, coming back home the next day, was perfect also for the first 2 hours, then i noticed photo#1 on the panel, autopilot/flight director was still holding heading and altitude fine, i thought "never seen 10 degrees down yet the machine was flying perfectly straight and level?"  I was at 25K, pretty clear air, had some weather to navigate up ahead but the machine was running so smooth and level, lasted for about 30 minutes, i was thinking i have never seen this before and this can't be a good thing to be happening but i am still flying nice a level, it shouldn't be happening but it is?  Will have to get this looked at when i get back down i guess.

Then 30 minutes later, Center calls me up and I am 300 to 400 feet high and to check my altimeter? I said, ya, will reset to 29.92, lol.  Well, the autopilot decided to climb now and i clicked it off and returned to 25K,  then i saw photo #2, took a picture for future trouble shooting and hand flew the bird the next 1.5 hours around some weather in and out of IMC, but used the co pilot artificial horizon into the home airport, visual approach luckily but was still a nice flight and no passengers even knew about hand flying and any issues at all. 
Alot of interesting thoughts i have reflecting on this non eventful flight i had of course.  And maybe with a new G600TXi, failures are almost nonexistent perhaps.  But having dual engines, dual instruments, dual hyrdaulic pumps, dual pilot tubes, etc... are why we like and gravitate toward these type of aircrafts?  Then i thought also, if i were in the soup needing to shot a low approach, do i move over to the copilot side and shoot a nice GPS approach on the back up GPS on the copilot side with the instruments in front of me, instead of looking way over to the right trying to shoot from the left?  Never trained on the right side for low IFR, but our planes you can be PIC for either seat, how many pilots here can fly their bird efficiently from the right?  Do you train an hour or more each year or so from the right with your recurrency? Well i have not yet, I never got my instructor rating so i don't have much time on the right, but probably will be doing some right seat time just to try something different and become more well rounded?
Anyways, thanks to Tim again at Byerly to help me trouble shoot this issue of the vertical gyro, he is extremely helpful and i am grateful to have someone like him with his expertise to call in an instance.  I am now stuck in the "hell hole" trying to get one screw out as someone in the past used a nut on the bottom instead of nut plate as the nut plate was probably stripped out I am guessing.  I don't have the correct tools for this job and might hire someone with more patience than me to remove this last screw to remove the gyro and get an overhauled unit installed in the back. Working for over an 1.5 hours in the "hell hole" to get one screw out makes me look incompetent as my flash light died, but it truly makes me think these avionics guys are some special type of immortals who don't stress out in impossible places or situations? The respect I have for these guys/gals is just incredibly high.
I have never entered this "hell hole" in the past, but looking at all the devices back there now, i have learned alot of where things are and what does what and how it is mounted and connected is amazing and the high level of respect I have for the people who work on our planes.
Sorry for the rambling and book here i have written, but i have had alot of good lessons and reflecting on many things the last few days here regarding flying, training, equipment, maintenance personnel, avionics, correct tools, etc...
 
 

[schrambow]

photo#1,

straight and level here in flight

[schrambow]

Photo#2

Still straight and level in actual flight here too!

[donv]

I had one fail like that in a 690 many, many years ago. At night, too. I also had one fail on departure in a Learjet 35, also at night and on a black hole departure. A good tip is to cover the bad one with a PostIt so you don't get confused.

I would strongly suggest doing some approaches with that attitude gyro covered so you can see what it is like. In my airplane, flying it cross cockpit is no big deal, except with the old mechanical HSI it was very difficult to see the glide slope indicator on the right side. That is one reason I now have a G5 over there as an HSI.

I would not switch seats, for sure. Flying cross cockpit really isn't too bad... I would prefer not to have to go to 200 1/2 that way, and would consider diverting to somewhere with decent weather if that were an issue.

I'm glad it all worked out!

[Adam Frisch]

This fills me with dread, because after the failure of installing the Aspen in my panel, they're putting the old Collins/Sperry back and I just know it's gonna misbehave. Last flights it had not captured GS and I had to do them on the backup.

What is the best shop for troubleshooting/overhauling these old instruments in the US?

[donv]

I think Duncan is still the go-to place for these. There is a point where a G600 starts to make sense, just from a cost point of view. Years ago, like 2006 or so, Aero Air put G600s in all of their 690s strictly because of maintenance costs on these old gyros.

[schrambow]

There are a bunch of shops out there to overhaul and rebuild them.  Mid-Continent,  Southeast Aerospace, Duncan are a few of them, i am sure there are a lot more out there if you look.   Just type in the part number you have in their website and you can find the overhaul price with or without a core.  1.8K to 4K it looks like the price range, 6 month warrantee seem standard from them i guess also.  With so many G600's being installed, i assume most shops have some spares (non overhauled) laying around also.   

[Adam Frisch]

I think Duncan is still the go-to place for these. There is a point where a G600 starts to make sense, just from a cost point of view. Years ago, like 2006 or so, Aero Air put G600s in all of their 690s strictly because of maintenance costs on these old gyros.

Problem on the pre-690's is that almost nothing is approved to drive the A/P.

[donv]

Adam, if I were you I would look around and find a spare set of gyros and displays. Given all the stuff being removed for Garmin replacement, this is probably a pretty good time and would be cost effective.

And, if you have one on the shelf, you can be sure the one in your airplane will never break!

[Adam Frisch]

Ha! Good point, Don!

[Steve binnette]

The G600 not bullet proof either.  I had this happen outside of radar coverage in northern Canada.

[donv]

G600 is certainly not perfect. The difference is that they fail less often, and more importantly you can get an exchange unit headed your way within hours.