Vacuum failure

[Guest]

It seems that Thermoid Co may also be the builder of Mooney engine inlet ducts.

http://www.thermoid.com/wp-content/uploads/AERODUCT-Aviation-Ducting-and-Hose-Products-Catalog.pdf

Clarence

[EricJ]

22 hours ago, jaylw314 said:

Hey @M20Doc, what does "SCAT" actually stand for?  It seems a rather unfortunate name more reminiscent of proctology... 

My recollection is Silicone Collapsible Air Tubing.    Might be "coiled", but I seem to remember it was actually "collapsible".   CEET is lined but I don't recall the actual acronym.    Seems to be non-trivial to locate, too.

 

[Pasturepilot]

I'd always heard it was Standard Category All Temperature. 

Either way, I think we're all mostly correct! It's useful for a number of applications when you need air routed about. 

SCET Was Extreme Temperature, I think. 

[0TreeLemur]

Learning & enjoying...  I had my engine mounts replaced last week.  Worth the $.  She purrs and whirs smooth as a sewing machine now.    Since then my vacuum gauge is reading 4.5 when before it was set to 5.0.   Weird.  Any ideas?   Ahem.   Sane ideas?

[Jeph357]

• 9 
• Quote

0TreeLemur     504

•  
•  
•  

Posted 3 minutes ago

Learning & enjoying...  I had my engine mounts replaced last week.  Worth the $.  She purrs and whirs smooth as a sewing machine now.    Since then my vacuum gauge is reading 4.5 when before it was set to 5.0.   Weird.  Any ideas?   Ahem.   Sane ideas?

 

 

When was current vaccuum pump installed? If it's been 500 hrs  or more than a few years think about replacing (prevent) especially if you do alot of IFR or be prepared for a vaccuum system failure. I've been in 2 seperate aircraft that the vaccuum pump failed once as a  passanger, once pic luckily both times, able to raise my eyes from panel and all was well. Not always the case 

•  
• Quote

•  

[M20F-1968]

On 8/27/2019 at 8:18 PM, MBDiagMan said:

From now on I will be replacing the pump on a preventive maintenance basis.

About four weeks ago I headed over the top on a 250nm flight.  About 150 nm or so was over solid overcast with a METAR and forecast of VFR at my destination.  I got about halfway across above the overcast and saw the AI turning severely.  I looked at the horizon and I was wings level.  I looked at the suction gauge and it was on zero.

 It wasn’t serious because I was confident that I had VFR ahead and I had about five hours of fuel on board.  That said I still felt uneasy.  If I would have had to go through the overcast it would have been less than ideal without my vacuum driven instruments.

It got MY attention!, 

If you are flying IFR, you need an electric backup AI.  AI redundancy is critical, even if you regularly practice partial panel (which most of us do not).

I have three artificial horizons, the Garmin G600, a 2" Midcontinent electric, and a 3" vacuum driven AI (along with a vacuum driven retractable step).  I have a RAT (air driven alternator) as a back-up electric source.

John Breda

[N201MKTurbo]

I have an electric standby vacuum system sitting in my hangar if anybody wants it. I have 3 attitude sources without it and a small useful load, so I took it out.

[0TreeLemur]

I have an Aerovonics AV20S installed, which provides plan B backup attitude indication, plus the Stratus as plan C.  The AV20S always agrees with my vacuum AI.

[Bob E]

Hey Brett,

I remember when I first bought my Mooney 33 years ago (yep!) and how little I knew about it, and about flying, and about annuals and maintenance, etc.  My recommendations:   1.  Find a mechanic to do your annuals who knows older Mooneys like yours at least somewhat.  2.  Have anyone who is familar with the O-360 engine give you a tour of what's under the cowling so you know what and where everything is -- where the throttle, mixture, and prop cables are, where the EGT sensor is, where the landing light wires go past the exhaust, and yes, where the vacuum pump is.   3.  One advantage of older aircraft is that the ADs have kind of settled down, but the disadvantage is that parts are harder to find.  If you plan on keeping your aircraft for a while -- and when I bought mine as a single guy I never dreamed that I'd still have it three decades later, or that my future son would get his instrument rating in it! -- don't skimp on anything, especially preventive maintenance.  Replace the fuel-filler O-rings before they really have to be replaced.  Know the service life of your battery and replace it just before it fails.  4.  If you upgrade, buy quality.   Yellow-tagged used avionics from Garmin or Bendix/King can be a smarter investment than new avionics from a company that might not be around in five years.   I hear you on not wanting to get rid of the vacuum system just yet, but remember:   Not only did you just lose your vacuum pump, but you also have two other vacuum-driven instruments with moving parts that are expensive to overhaul.  If you invest in another vacuum pump, you're financially committing yourself to more outdated technology and to overhauling rather than replacing that AI later.  Now may be the time to consider G5's, even if you have to finance them.  Good luck!  Fly safe.

 

[David Lloyd]

So many times we read that an attitude indicator or directional gyro acts weird and then the vacuum gauge is discovered sitting on 0.  Or the radios quit working and then the volt or amp meter is discovered to show a power loss.  If the vacuum gauge (or other instruments) are not in your scan, install an annunciator panel and/or backup power sources.

[MBDiagMan]

12 hours ago, N201MKTurbo said:

I have an electric standby vacuum system sitting in my hangar if anybody wants it. I have 3 attitude sources without it and a small useful load, so I took it out.

How much weight does it add?

[N201MKTurbo]

9 minutes ago, MBDiagMan said:

How much weight does it add?

It was about 10 Lbs.

It also put me over my alternator ELA limit.

[EricJ]

11 hours ago, David Lloyd said:

So many times we read that an attitude indicator or directional gyro acts weird and then the vacuum gauge is discovered sitting on 0.  Or the radios quit working and then the volt or amp meter is discovered to show a power loss.  If the vacuum gauge (or other instruments) are not in your scan, install an annunciator panel and/or backup power sources.

One of my fave additions so far has been the EI AV-17 voice annunciator, aka the GA Bitchin' Betty.   My IFD also has some handy audio callouts, like the 500 ft callout on descent/approach.  If the AV-17 speaks up at any time it immediately gets my attention, since it's usually quiet and is hooked up to useful things like the vacuum LED, engine monitor, gear warning, etc.   Love that thing.   I think she already saved me a motor when I forgot to open the cowl flaps on a taxi-back practicing GPS approaches at an untowered remote airport...as soon as the engine monitor tripped on the CHTs on climb out she spoke up.   D'oh.   Took care of that right away. 

I have to turn her off right after touchdown, though, or she won't shut up about the vacuum being out of range at idle.   So one of my critical takeoff/climbout/go-around checklist items is to make sure she's turned on.   Looking forward to deleting the vacuum system entirely, though.