Replace vacuum AI with electric

[jeharlan]

I have been trying to figure out what has to be done to remove my orignal AI and replace with electric. I can find where if the unit has an STC (which no manufacture has done) you can remove the vacuum. I would like to replace with a LifeSaver from Mid-Continent. Has anyone else made this change. I am in a M20S Eagle.

 

Thanks

Jeff

[N601RX]

Replacing one TSOD device with a similar TSOD shouldn't require a STC or Field approval. See FAA AC 20-41a.  The Mooney type certificate allows removing the rest of the vac system once no vac based instruments are left.

 

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%2020-41A/$FILE/AC20-41A.pdf

[OR75]

replacing a TSO'd with another TSO'd device should not require an STC or field approval indeed. However, the FAA does require an A/C to have 2 independant systems (1 electric + 1 vacuum) or 2 independant vacuum or 2 independant electric. 

I don't think you can move all your device to electric unless you have 2 independant electric systems. I don't know if the life saver counts as a second electric system but I doubt it does.

 

One thing they allow is to change your electric turn coordinator for an electric AI. So you end up with two  AI : 1 electric and 1 vacuum 

[Cruiser]

I have been trying to figure out what has to be done to remove my orignal AI and replace with electric. I can find where if the unit has an STC (which no manufacture has done) you can remove the vacuum. I would like to replace with a LifeSaver from Mid-Continent. Has anyone else made this change. I am in a M20S Eagle.

 

Thanks

Jeff

The best approach is to talk with your avionics shop and/or A&P /IA before doing anything. I would want to be certain the plane will be signed off before starting anything.

[WardHolbrook]

Why remove it at all? From a safety standpoint having a second AI is definitely the way to go. 

[jeharlan]

Replacing one TSOD device with a similar TSOD shouldn't require a STC or Field approval. See FAA AC 20-41a.  The Mooney type certificate allows removing the rest of the vac system once no vac based instruments are left.

 

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%2020-41A/$FILE/AC20-41A.pdf

Where do I find the  documentation for "Mooney type certificate allows removal the vacuum system" at?

 

Thanks!

[N601RX]

On the FAA website.  I think it is covered in a footnote.

 

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameSet

 

 

 

[jeharlan]

On the FAA website.  I think it is covered in a footnote.

 

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameSet

I found this but it points to an STC'd replacement and no AI maker has done that work.

 

Aircraft models that originally were certified with vacuum powered attitude systems that have those systems replaced with a non-vacuum powered attitude system: If the Primary Attitude system has been replaced with an FAA Approved STC’d installation that meets the requirements of 14 CFR 23.1303(f)(i)(ii)(iii)(iv)(v)(vi), 23.1311(a)(1)(2)(5)(6)(©, 23.1321(a)(©(d)(1), 23.1331(a)((1)(2)©, thereby leaving no operational systems dependent on a Primary or Standby (if equipped) Vacuum system, then the Primary and Standby (if equipped) Vacuum pumps and associated lines, manifolds, etc may be removed from the aircraft. Refer to engine

manufacturer’s instructions of removal and capping off of engine driven vacuum pumps. 

[jeharlan]

Why remove it at all? From a safety standpoint having a second AI is definitely the way to go. 

The primary issue is that we have an AirWolf system with the wet pump and after repeated calls and changes to the system it ALWAYS pushes oil out the vent line. I am tired of a belly full of oil and want to remove the system and go with the RCA2600 with battery backup.

 

Does anyone have any thoughts on why I would not want to do this?

[OR75]

There was an article in a recent "Flying" magazine (2013) titled "the all electric mooney" (or something like that)

It explain what is required to remove the vacuum system

 

I highly doubt you can just get rid off the vacuum pump system unless you have 2 independant electrical generation systems. Do you have 2 electrical independant systems ? (two alternators, 2 batteries , etc , etc ... )

[M20F-1968]

When I was considering what was to be in my panel, I spoke with Sigma-Tek.  They cautioned against my utilizing an electric AI to replace the vacuum instrument stating that the vacuum instrument was quicker and more reliable in righting itself after an unusual attitude.   Given that conversation, I left the vacuum instrument in the panel as the primary and used a 2" Mid-Continent as the backup.  Then I redesigned the panel with the Garmin 600, and had two AI's in addition.  I was going to keep the vacuum as a back-up given Sigma-Tek's comments.  Also, the Back-up battery for the Mid-Continent is both expensive to purchase and maintain.  I kept the 2" electric as a 3rd AI (Garmin 600, Vacuum AI, 2" electric Mid-Continent) but did not use the battery back-up for the Mid-Continent, but rather installed a RAT as a back-up alternator which will power the panel if need be.  I thought the use of the 2" AI would have more utility than what I would recover by selling it.

 

John Breda

[fantom]

...I kept the 2" electric as a 3rd AI (Garmin 600, Vacuum AI, 2" electric Mid-Continent) but did not use the battery back-up for the Mid-Continent, but rather installed a RAT as a back-up alternator which will power the panel if need be.  I thought the use of the 2" AI would have more utility than what I would recover by selling it.

 

 

[jeharlan]

There was an article in a recent "Flying" magazine (2013) titled "the all electric mooney" (or something like that)

It explain what is required to remove the vacuum system

 

I highly doubt you can just get rid off the vacuum pump system unless you have 2 independant electrical generation systems. Do you have 2 electrical independant systems ? (two alternators, 2 batteries , etc , etc ... )

Yes the secondary system is the battery backup unit ESP-1 for the RCA2600.

[OR75]

Yes the secondary system is the battery backup unit ESP-1 for the RCA2600.

I did not know the RC Allen backup battery system is approved as a second system. are you required to change the backup battery once in a while ?

usually battery have a limited life

i heard the sigma tec life savers battery is $$$ to replace.

i am looking at replacing my TC with the RCA 2600 but have not made the jump yet.

[KSMooniac]

I have the Mid Continent Life Saver gyro with a battery backup and find it to be excellent.  I have not noticed any difference in unusual attitude performance vs. my vacuum Sigma Tek, either, and I suspect John heard some crap from Sigma Tek since they don't have a product to compete in the electric arena IIRC.  

The battery replacement was quite a shock when I had to do that a few years ago (previous owner installed the gyro) but after getting over the sticker shock ($300 or $350) I did a closer inspection of the battery and found it to be 3 commercially available cells chained together, so I just bought those off the shelf for under $50 and renewed the battery pack.  

 

The AOPA article on the electric J was enlightening, and I plan to try a similar path whenever I get around to installing an Aspen or other PFD.  It would be nice to remove the weight of the vacuum system someday and have a more reliable panel.  I would likely install a backup alternator on that pad too.

[jetdriven]

When I was considering what was to be in my panel, I spoke with Sigma-Tek.  They cautioned against my utilizing an electric AI to replace the vacuum instrument stating that the vacuum instrument was quicker and more reliable in righting itself after an unusual attitude.   Given that conversation, I left the vacuum instrument in the panel as the primary and used a 2" Mid-Continent as the backup.  Then I redesigned the panel with the Garmin 600, and had two AI's in addition.  I was going to keep the vacuum as a back-up given Sigma-Tek's comments.  Also, the Back-up battery for the Mid-Continent is both expensive to purchase and maintain.  I kept the 2" electric as a 3rd AI (Garmin 600, Vacuum AI, 2" electric Mid-Continent) but did not use the battery back-up for the Mid-Continent, but rather installed a RAT as a back-up alternator which will power the panel if need be.  I thought the use of the 2" AI would have more utility than what I would recover by selling it.

 

John Breda

I agree, John. The vacuum AI is erect and reliable 20 seconds after startup. The Castleberry takes 4-5 minutes.

[Marauder]

 

This help a little until John posts his?

 

 

[OR75]

I agree, John. The vacuum AI is erect and reliable 20 seconds after startup. The Castleberry takes 4-5 minutes.

 

 

The RC 2600 is different technology:  it is AHRS rather than an electric motor. I suppose it would come up faster . Does it ? Could help justify the $$$ difference.

I like that it is very light weight (The Mooney panels are overweight and tend to sag) but read some not so good review on the RC 2600 reliability. Also read that the latest model is more robust.

[Bennett]

My Mid-Continent electric AI erects almost immediately after the avionics switch is turned on.

[M20F]

I have always been of the mindset that vacuum + electric is a nice redundancy.  If  for whatever reason my electrical system fries it is nice to have a vacuum system as a back up and  on top of that you can include a cheap stand by vacuum system.

 

Electric AI + Battery Back  Up + Vacuum AI + Standby Vacuum + iPad AHRS = much better chance of not dying

 

In short why limit yourself.

[jeharlan]

Well after talking to the FAA and a DER and Brian Kendrick I have come around to the fact that unless I install an Aspen or Garmin unit with the STC then I would have to go the full distance and get a field approval which would require engineering. Also after talking with Brian it appears that someone let one of the filaments out of the AirWolf. So we have ordered the filament and hope that this will resolve the issue with oil mist coming out the vent of the AirWolf.

 

This was my first post on here and I wanted to thank everyone for all their help and ideas.

 

Jeff

[Cruiser]

Brian certainly knows Mooneys. he was Mooney's chief pilot/inspector and ran the factory's customer upgrade and maintenance center before they closed.

 

 I met him in Fredericksburg after the MAPA convention there in 2012. 

 

I encourage anyone needing work on their Mooney to contact him. He is one of the best.

[NotarPilot]

Have you considered getting an AHRS gizmo for the iPad and using that as a back up AI? It might not be a permanent installation but it might accomplish the task you seek.

[chrisk]

In two weeks, my bird goes in for an avionics upgrade.   Audio panel and GTN650 are a certainty.   I'm considering adding an ASPEN PFD, or adding an RCA2600 AI and a GPSS module.  Having said that, the RCA2600 and GPSS are already more than half of the cost to add an Aspen.  And the King HSI will eventually break and cost $$$ to fix. 

 

Anyway, I plan to keep the vacuum AI no matter what I do.   For me, AI redundancy is more important than removing a vacuum system from the plane. --Now, I might change my mind when my vacumm pump eventually dies.

[fantom]

Electric AI + Battery Back  Up + Vacuum AI + Standby Vacuum + iPad AHRS = much better chance of not dying

 

In short why limit yourself.

 

All the choices might confuse to poop out of you