Vacuum pump dying...

[Parker_Woodruff]

Well, I'm set to have all my avionics work done starting Monday afternoon.  Unfortunately as I was flying today my vacuum pump was barely holding above 4 inches in cruise and I noticed some slugishness of the attitude indicator on the ground.

 

Since I'm getting a G500, I was planning on leaving my vacuum driven attitude indicator as the standby, but now with the impending failure of the vacuum system, I'm thinking about going the route of getting an electric standby attitude indicator.  To be legal, it would have to have the battery pack.  So I'm at a crossroads:

1) What is the most budget-minded certified electric standby attitude indicator?  In other words, how much more is this going to cost me than replacing a vacuum pump?

2) If I do go that route rather than replacing the pump, can I entirely remove my vacuum system?  If I get an autopilot, I can see myself going for one of the less expensive options like the STEC system 30 which would not require one...(correct, right?)

----(a) I have a standby electric vacuum system that is operational.

3) How much useful load could I gain without the primary vacuum system and the backup vacuum system installed?

[FoxMike]

Parker,

If that were my project I would buy a new vacuum pump and install it soon.  The weight of the electric gyro will likely offset the removed vacuum parts.  Vacuum gyros are less expensive to maintain than mechanical/electric.  You may have a trip in your future where the master has to be shut off and you will be glad you have a vacuum system.

[Parker_Woodruff]

Quote: FoxMike

Vacuum gyros are less expensive to maintain than mechanical/electric.  You may have a trip in your future where the master has to be shut off and you will be glad you have a vacuum system.

[N6843N]

Are sure it is the pump? Check the hoses filters and even the exaust on the installed pump, it is a favorite spot for spider nests. As mentioned you will lose usful load with an electric standby. A lot of owners neglect the maintenance on the vacuum system, I dont really know why, I did some work for flight school once that had a fleet of new 172's, all of them had their original filters both inlet and regulator.

[KSMooniac]

I have a Mid Continent electric AI with a battery backup, and it is a nice unit.  I'm very happy with it, especially since the previous owner installed it. I believe it costs about 20x what a rebuilt Rapco 211CC vacuum pump costs.  I expect the weight of the pump + regulator + plumbing + vacuum AI will exceed that of the electric gyro and battery pack by a couple of pounds at least, but that is just my educated guess. 

Unless you have a lot of extra money to add to the upgrade, I'd just check the vacuum plumbing and put on a rebuilt pump for now as long as your AI has been behaving.  If your AI acts up in the future, then you might think about ditching the entire system since the AI overhaul will cost 2-3x what the vacuum pump costs.  The vacuum pump might also fit your 172, so you could save it for a spare.

[Parker_Woodruff]

Quote: KSMooniac

I have a Mid Continent electric AI with a battery backup, and it is a nice unit.  I'm very happy with it, especially since the previous owner installed it. I believe it costs about 20x what a rebuilt Rapco 211CC vacuum pump costs.  I expect the weight of the pump + regulator + plumbing + vacuum AI will exceed that of the electric gyro and battery pack by a couple of pounds at least, but that is just my educated guess. 

Unless you have a lot of extra money to add to the upgrade, I'd just check the vacuum plumbing and put on a rebuilt pump for now as long as your AI has been behaving.  If your AI acts up in the future, then you might think about ditching the entire system since the AI overhaul will cost 2-3x what the vacuum pump costs.  The vacuum pump might also fit your 172, so you could save it for a spare.

[Parker_Woodruff]

Quote: N6843N

A lot of owners neglect the maintenance on the vacuum system, I dont really know why, I did some work for flight school once that had a fleet of new 172's, all of them had their original filters both inlet and regulator.

[docket]

Parker, the problem that I ran into the the G500/G600 is that the STC only allows two electric horizons and they are specified in the STC.  I know one of them is the Mid Continent unit.  You are required to also install a backup battery system to be legal since your primary is electric (i.e. total electrical failure leaves you blind).  After I priced it out the upgrade to the electric horizon was just not something that I wanted to bite off at this time.  And, by the way, the real deal on electric horizons is the L-3 Trilogy as it lets you get rid of all of your backup instruments.  The only problem is that you would have to get it field approved because it is not on the STC.  I spoke with L-3 and Garmin and they are not planning to add it to the STC list.  Lastly, when I spoke with L-3 they are going to have a unit out with an integral backup battery shortly.

[Parker_Woodruff]

Well I have good news.  The regulator had a loose piece on it so I'm only out about $35.