Replacing vacuum system for electronic standby instruments.
I am considering removing my vacuum (standby) system in my '05 G1000 T182T and replacing it with maybe a garmin 275. Has anyone done this? approx cost? I dont think major panel work is needed as replacement unit fits into current standby inst. holes. I only need to replace my backup "3 pack" but would welcome more capability.
Comments
Hi Keith,
I see there were no comments yet on your proposed upgrade. If you have received some recommendations through research and other sources and can find the time to share what you have learned with our current and future members here in the forum, it would be much appreciated.
Regards,
Mike
Keith I'll just add a comment that replacing one instrument for another approved unit like the 275 shouldn't be a problem. The labor cost comes in when you want to integrate the 275 for all the added capacity. If you wanted to swap to swap I don't think you'd have an issue putting two of those in to get rid of your standbys. Run that by your shop and see what they think. I put a standalone 275 in and it's very basic. Carl
IA 47yr A&P DAL A/C Inspector 172n
Not sure I understand the question behind this question, so I'm going to address only part of it, with a starting assumption.
The assumption is this: the "vacuum (standby) system" is something that takes vacuum from the intake manifold, such as a Precise Flight Standby Vacuum System (SVS).
The SVS should have had an accompanying FAA Form 337 documenting its installation, signed off by an IA, way back when it was installed. Removal of the SVS, then, is just a matter of removing all of the SVS pieces and parts. In this case, that's probably a saddle clamped to a hole in a rubber part of the intake manifold, the tubing from there, through a valve, to the vacuum side of the two vacuum-powered gyros: the directional gyro (DG) and artificial horizon (AH). The SVS probably connected to the vacuum system at a "T". The SVS plumbing is removed up to the "T", and the two remaining legs get spliced together.
There usually is a vacuum/pressure sensor to detect loss of vacuum and enough wiring to drive a red light bulb on the panel. All of it goes. Either patch the hole in the intake manifold or replace the rubber joint, depending on how picky you are. The last step is another FAA Form 337 documenting the removal of the SVS, referring back to the installation Form 337. Don't forget to update the Equipment List (you do have a current Equipment List, right?) and calculate new Weight and Balance (ditto).
Whoops, one more thing. You have disturbed the vacuum system, so new pitot-static and transponder/altitude reporting certification is required.
If my basic assumption is off, but it's one of those kits that power a second vacuum pump with an electric motor, then it's even easier. Everything above applies, except you don't have to patch the intake manifold. You still just remove all of it, and do the paperwork (Form 337, Equipment List, Weight & Balance).
I suppose your SVS might instead be the addition of a second engine-driven vacuum pump that sits on an accessory pad just like the primary pump does. Depending on how this type of SVS was certified, the paperwork might be more involved. I'm not familiar with the specifics of this model of 182 (my 182 was a whole lot older than yours), but you should check to see if this second pump is part of the type certificate -- if so, an STC will be required for its removal. On the other hand, if it was done via a Form 337 (with or without an after-market STC as basis for the installation), then un-doing it is simpler. Remove the second pump and all of its plumbing, and complete a Form 337 documenting removal -- referencing the after-market STC if there was one.
Final part of this is I'm assuming you plan to remove the entire vacuum system in favor of electronic DG and AH. That's something many shops already know how to do, including the paperwork requirement, so I won't belabor the topic here. If that's what you plan to do, then there's no need to reconnect the rest of the vacuum system, nor to re-certify it. You won't have a vacuum system to test!
Last comment: Because the GI275 (and similar equipment from competitors -- do your research!) are the same shape and size as your vacuum-powered gyros, they don't require fabricating a new instrument panel. That will save you many thousands of dollars and many days of time.
Hope that helps.
We took out the vacuum pump in our Cessna 150M along with the associated flight instruments. Replacing with two G5’s and got a few HP back from it!