GeorgePerry Posted September 12, 2015 Report Posted September 12, 2015 (edited) Question for someone who actually knows the answer...I would like to swap out my old Vacuum driven AI, and replace it with an RCA 2600-3 on my M20S I've heard that the TCDS for the M20S now allows for this? Can anyone confirm that to be true? I'm referencing Note 24 on page 58. TCDS.tiff TCDS.tiff Edited September 12, 2015 by GeorgePerry Quote
M20S Driver Posted September 12, 2015 Report Posted September 12, 2015 It sure would be nice to get rid of vacuum pump and the back up vacuum pump. What at is the cost? Quote
ArtVandelay Posted September 12, 2015 Report Posted September 12, 2015 (edited) It sure would be nice to get rid of vacuum pump and the back up vacuum pump. What at is the cost? I understand having a backup vac for primary instruments, but do you really need a backup vac for a backup instrument? You might consider removing the backup vac for backup instruments especially if its electric. You're having a bad day if your glass panel goes away and at the same time your vacuum pump dies as well. Edited September 12, 2015 by teejayevans clarity Quote
M20S Driver Posted September 12, 2015 Report Posted September 12, 2015 I understand having a backup vac for primary instruments, but do you really need a backup vac for a backup instrument? You might consider removing the backup vac for backup instruments especially if its electric. You're having a bad day if your glass panel goes away and at the same time your vacuum pump dies as well. My AI is vacuum driven and it is the primary. I don't have an AI back up except for the Ipad with Stratus. Quote
kortopates Posted September 12, 2015 Report Posted September 12, 2015 Question for someone who actually knows the answer...I would like to swap out my old Vacuum driven AI, and replace it with an RCA 2600-3 on my M20S I've heard that the TCDS for the M20S now allows for this? Can anyone confirm that to be true? I'm referencing Note 24 on page 58. TCDS.tiff TCDS.tiff Note 24 was not to give you authority to replace your vacuum based AI with an electric AI of some type - you always had the authority to do that as along as the AI was approved or STC'd etc such as Aspen or just a TSO'd Electric AI. The problem was, and the reason for Note 24, was that you still had to keep your vacuum system installed because the TCDS listed it - even though you had nothing connected to it! Note 24 now gives you the authority to pull it when its no longer used for anything. It was early adopters of glass that got the factory to add that note. I have the same issue in that I have only one vacuum instrument, my King AI, which I intend to replace with glass soon. But I'll still have to keep my vacuum system unless I am willing to replace my vacuum speed brakes with electric. Its tempting but another $4k (without labor) for new electric speed brakes when my vacuum ones work fine? I don't think so. Quote
carusoam Posted September 13, 2015 Report Posted September 13, 2015 (edited) MS's leader, Craig, lead a battle to remove the vacuum system on his J when he added the Aspens and a back-up electric AI. sorry George, I don't know the answer, but I hope this might ignite a memory by somebody who does... best regards, -a- Edited September 13, 2015 by carusoam Quote
ShermAv8tor Posted October 5, 2015 Report Posted October 5, 2015 George, good news....check out the FAA's recently released policy statement in regards to your question..... search on FAA website for PS-ACE-23-08 released mid September. Quote
kmyfm20s Posted October 5, 2015 Report Posted October 5, 2015 I recently had my my backup vacuum AI replaced with electric, it was my last vacuum dependent instrument. The shop I use is by the book and they had no problem removing my vacuum system in my M20S. I gained 11lbs of useful load. 2 Quote
cliffy Posted October 21, 2015 Report Posted October 21, 2015 the referenced policy report shows as a draft and not final Anyone have one showing final adopted date? Quote
cliffy Posted October 21, 2015 Report Posted October 21, 2015 Found it! http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/6A24902AE5F1AEAC86257EC1005B2FBC?OpenDocument&Highlight=ps-ace-23-08 Final 9/14/15 Quote
carusoam Posted October 21, 2015 Report Posted October 21, 2015 The power of MooneySpace. Type in a question. And the answer just appears. Best regards, -a- Quote
MB65E Posted October 21, 2015 Report Posted October 21, 2015 Awesome Cliff!! Nice find. That means all vintage Mooneys too. Sub part E on the M20 TCDS allowed for this in the past, but it requires its own standby power. If you have a volt meter monitoring ships power this AC finally emliniates the need for the Standby battery on the ADI. That's nice because my replacement ADI battery from RC Allen is expensive. I'll keep my standby battery up to date, but for everyone else, Volt meters are cheap!! -Matt Quote
tony Posted October 22, 2015 Report Posted October 22, 2015 The reason your backup instrument is powered by a vacuum source is to mitigate the failure mode associated with a complete loss of electrical power. During the certification process the OEM had to create a functional hazard assessment (FHA). This FHA was one of the artifacts created to show compliance with 23.1309. Without an STC for your aircraft, you will need to show the FAA why the installation of this device will not invalidate that assessment. Not saying you can't install this, but I'm pretty sure you will need to provide an independent power source and have a DER sign off an analysis based on AC 23.1309. that shows the loss of attitude is extremely improbable. If it were my airplane. I would leave the vacuum based instrument. Quote
Marauder Posted October 22, 2015 Report Posted October 22, 2015 The reason your backup instrument is powered by a vacuum source is to mitigate the failure mode associated with a complete loss of electrical power. During the certification process the OEM had to create a functional hazard assessment (FHA). This FHA was one of the artifacts created to show compliance with 23.1309. Without an STC for your aircraft, you will need to show the FAA why the installation of this device will not invalidate that assessment.Not saying you can't install this, but I'm pretty sure you will need to provide an independent power source and have a DER sign off an analysis based on AC 23.1309. that shows the loss of attitude is extremely improbable. If it were my airplane. I would leave the vacuum based instrument. Two observations I had reading through the document; a backup battery is required although they indicate you can use the start battery if you can prove a rate of charge at the start of the flight. The second one is that multi function units like an Aspen can't be the backup. It was very clear that the unit was a standalone AI with the only allowable second feature was a turn rate indicator. I was really hoping my second Aspen would be allowed to act as the backup. Sent from my iPad using Tapatalk Quote
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