Aeon Piston Pump

[johnggreen]

Soon after acquiring my Bravo in 2005, I lost my AI/Flight Director.  The rebuild, if I recall, cost well over $2,500, and the rebuilder said that the unit failed due to carbon.  My mechanic checked the filters and said they were doing all that could be done.  Not wanting another rebuild due to carbon, I converted to the Sigma-Tek Aeon piston pump, which, of course, has no carbon vanes to deteriorate. 

So far, the unit has performed flawlessly, but coming up on six years, and flying a lot of IFR, I started thinking about replacing the pump just for good measure.  I was browsing the net just seeing if there were any late articles on the AEON and its relieability in the field, and found almost nothing after 2007.  I was also surprised to see that there had been some early difficulties that resulted in a couple of redesigns of the unit; both redesigns coming after my unit was manufactured.

At any rate, it got my curiosity going.  My experience has been excellent, and after 2007, there is nothing to indicate that there have been any recent issues with the pump, but nothing?  Not good reports, not bad reports; nothing.

So, are there any other Bravo owners with the Aeon and what was your experience.

JG

[AndyFromCB]

Get an dual aspen setup, remove all vacuum pumps and put in a RC 2600 with a batery backup. Been working like a charm in my Arrow (ok, so I couldn't remove the vacuum due to type certificate, so the vacuum gyro is just sitting there on the right side gathering dust). Getting the same setup in the Bravo before I take it IMC.

[johnggreen]

Astelmaszek,

I have a hell of an airplane with extremely good, functional equipment that will carry me to any part of this country in almost any weather.  I simply want to maintain its reliability and want to know if anyone besides me has direct AEON pump experience.  The only other alternative that I would consider right now is an Airwolf wet pump with seperator, but that is three times the cost of the AEON pump.

As for the glass cockpit.  My Bravo has served me extremely well for the last seven years.  That being said, my mission is going to change some with a real need for more room and useful load.  Should I make that move, it will be back to a twin that will cost me at least four times as much to operate as the Bravo, so I won't make that move hastily or without serious deliberation.

If, and I say if, I back out of the twin and its expense, then, I will indeed either trade to a glass cockpit or rebuild mine, but that decision is simply not here yet.  So, my only question is, do I stay with the AEON or go to the Airwolf.

Please, don't anyone bore me with the latest and greatest dry carbon vaccum unit.  My King AI/FD would probably be five grand to rebuild now, or more.

JG

[AndyFromCB]

John,

I appologize, I meant to be sarcastic. My experience with vacuum pumps has been so miss and miss that I just gave up since I started flying in 1999. If the pump has really lasted 7 years and it's warranted for 2000 hours, why mess with a good thing. I assume you already have a good backup AI. If you don't, I really recommend the LCD RCA 2600. It's been flawless for me.

[Piloto]

Gyros are normally connected to the vacuum side of the pump, so it is almost impossible to get pump residues into them. If your AEON pump has been running good keep it. But keep in mind that at some point it may fail just like any other device in the plane. Just make sure you have an alternate option for when the failure occurs.

 

José

[jetdriven]

Every time you shut down the vacuum in the gyro cases can pull carbon dust into the gyros. Especially if the pump fails in flight. The CV1J4 filter installed between the pump and the gyros prevents this. We bought one and its waiting to go in. 

Like John I read about a lot of failures of the "B" and "C" revisions of the Aeon. However, the latest version there is not much talk.  I would gues they got it reliable. As important as gyros are, we are shifting to an Aeon pump when ours fails, and we will run it to failure this time because we are putting a Castelberry 12V attitude gyro in the panel. A vacuum failure wont be an emergency any more.  That and standby vacuum.

[Awful_Charlie]

I'm somewhat curious, never having heard of these before.  Assuming http://www.sigmatek.com/pages/prod_description/PD_ACC_aeon.html is the device, how does it cope with high altitude?  They are quoting a maximum altitude of 20,000', which potentially removes the top 5000' of Bravo capability, compared to the 'standard' vane dry air pumps which quote a max. alt of 30,000'.

FWIW, I'm still running a Rapco as my #1 pump which is 8 years old and with 900hours on it - by virtue of an Aspen it is driving a standby instrument, and also have the standby tailcone vac, and a LifeSaver, so I'll run it until it stops.  I do annual filter changes religously, except for the filters between the pump and the instrument, where I use the transparent ones and keep an eye on the every time the cowl comes off.

[johnggreen]

Astel,

Didn't take your comments as sarcasm.  Your comment is right on for long term, but right now, I'm looking at the short term.  I regularly fly from MS to VA and almost always will cross at least one weather system so IFR is "real world" to me. 

I have developed several maintenance habits over the years; yes, perhaps to excess.  For instance, the Slick mags in the Bravo have a MTBF of 500 hours so I rebuild at 250-350.  In the past, when I had an airplane with carbon vacuum pumps, I would replace one every annual.  Yes, I always made sure to have an airplane with two.  So, yes, I'm going overboard with replacing the Aeon less than halfway through its "time use" warranty, but it is past its calendar warranty.

As for backups, in the Bravo I have my primary AI, Aeon for primary vacuum, electric driven back up vacuum, back up electric AI, and my TC which I fly under the hood regularly, so yea, I'm backed up and up and up.  I don't intend to die in an airplane.

As Jetdriven pointed out, there just isn't any info on the latest version of the AEON, but I'm going to call Sigma-Tek and unless I find out something negative, I'm going to put a new one in no later than the next oil change.   What I did read on the early failures was that in some airplanes it would fail due to a particular frequency of vibration or something like that.  Don't really know.  That's why I asked.  Maybe somebody on this blog will have experience or more knowledge.

One last comment.  I have studied the glass cockpits pretty closely.  Needless to say, glass is state of the art and at any update, you would be pretty silly not to install it particularly in an airplane of significant value.  That being said, at the last reports that I saw, there has been no safety advantage shown in the field.  I've been flying steam guages since I was eleven years old (62 now FYI) and am pretty comfortable. 

Still, being an "old salt", I will admit to being blown away by the Ipad with Foreflight.  I just got it and used it for the first time on my flight to VA yesterday.   AWESOME BOYS, AWESOME!  The neatest feature must surely be that the entire chart for your flight is right there at the touch of a stylus.  When Center gave me a routing to a GPS intersection I had never heard of, the IPAd brought it up in about six seconds.  It truly increases one's situational awareness.

Hope you guys are taking advantage of this beautiful weather that is covering most of the country right now.  Tomorrow, I'll be heading back to MS over the Blue Ridge Mountains and yes, they are in full color.

Have a great weekend.

And, by the way, I'm here to see my first grandchild born to my daughter October 13, 2011, Hugh Agnew Gamble IV.   Life is Sweet!  Lord willing I'll be teaching him to fly the Cub in about 9 years.

JG

[jetdriven]

There is infant mortality to deal with too, regarding aircraft parts.  Your fresh engine or alternator is more likely to fail than one with 2000 hours on it, and I think the same with accessories.  Plus the small chance of disturbign something else which could then fail.  Now, for something like a vacuum pump in a single with no standby vac or electric AI backup, I would probably change it every 500 hours.  I am remedying that case with ours next week.  But dual vacuum pumps and a standby electric AI?  run those pumps till failure. They are not critical anymore.

I'm with you, John,  all the glass, autopilots, GPS, and TCAS wont make you a better pilot.  Mindset, training, and proficiency will. Your passengers deserve that.

[johnggreen]

You fellows are going to think I'm making this up.   On the flight back from VA today, my Aeon pump failed.  I swear.  The backup vacuum worked fine so I was able to keep using the autopilot.  The good thing is that the failure was slow and it was severe clear.  When the suction fell to 3.0 psi, my warning light came on but the AI continued in a stabilized condition.  

Well, I was going to replace it anyway.

JG

 

[Daniel]

Really, John, that is just too damned funny.

[jetdriven]

Heh you called that one right. However, you did get the most out of it, but wasn't it warranted to 2000 hours?  Our Rapco rebuilt pump has 900 hours on it. 

[johnggreen]

Daniel/Byron,

It's nice when failures in aircraft can be "funny".

I'm going to stick with the AEON subject to a call to Sigma-Tek today and availability.  I need a replacement tomorrow as I may need to go back to VA Thursday.

New week.  Lots to do.  "Get er done".

JG

[rbridges]

sorry to go off subject a little, but I have a standby vac.  In a setup like this, do you normally run until your primary gives out and replace it?   I wouldn't think you would replace a "good" primary vac until it shows problems if you have a standby.  Like John, you could fly using standby in an emergency. 

[johnggreen]

Rbridges,

The answer to your question is something of personal opinion and something of exactly how you use your airplane.  What I mean by that is if you are a VFR pilot, running a primary vacuum pump to failure is not a big thing.  If on the other hand, you fly in the real soup regularly, then you should (I believe) be pro-active.  My normal approach is to try to find out the MTBF (mean time between failure) of critical items and replace them at about 75% of that number.

I was about to replace my AEON pump anyway as it was getting some hours on it.  Yes, much less than 50% of the hourly warranty of 2,000, but since it drives my primary AI, which drives my autopilot and I regularly fly IFR, I tend to err on the side of caution.  I'm not made of money, but I can afford to keep my airplane in tip-top condition, and I do.

JG

[johnggreen]

Now, for the latest on the AEON pump.  As I told you guys, my pump failed yesterday on the way back from VA.  Yes, I was going to replace it anyway, but the whole point of this thread was to see if anyone else had any experience with the AEON.  Though it had a 5 year/2000 hour warranty, mine failed at 600 hour.  Still, the easiest thing was to go back with another one so I called Sigma Tek.

According to the lady I spoke with there, they have made some more revisions to the pump which have not, at this time, been approved by the FAA and so, at this time, the pump is not available for sale.

There you have it from the horses mouth.  I'm having a carbon vane pump put on tomorrow so I can get back in the air.  I also suspect that I won't be too far out from a Garmin G500.  Personally, I don't give a flip about glass or bells and whistles.  It is simply a question of the most reliable set up I can get in the airplane that carries the grandmother of my grandchildren.

I do sincerely hope that Sigma Tek gets the kinks out of the AEON.  This is one area that we need better equiipment than is on the market today (short of $$$$$ glass $$$$$).

JG 

[John Pleisse]

Quote: jetdriven

I would probably change it every 500 hours. 

 

[AndyFromCB]

John,

I too regulary fly IFR, now in an Arrow, soon in my new Bravo. My Arrow is a dual Aspen setup. You mentioned G500. I'd strongly recommend the dual screen Aspen setup with the autopilot interface and a RCA 2600 standby over the G500. Price will be about the same as G500. On a Bravo it will allow you to remove the vacuum system all together, save the weight and you'll have 3 independent attitude indicators, airspeed and altimeters, one independent of the pitot-static system as well. I have flow a Super Decathlon with the RCA 2600 and I can attest that it simply cannot be tumbled with the roll rates of a Bellanca so I would assume it would be even more reliable in a Mooney. Just my two cents.

Andy

[johnggreen]

Andy,

I appreciate your input.  You may be assurred that I will study both systems carefully before I pull the trigger.

The one number that will control all will be the MTBF and initial start up problems.  As of now, that puts the Garmin out front at least on the info that I have garnered.

First, I must decide if I am going to keep the Bravo.  I would like to move back to a twin for the room and useful load, but the operating cost over the Bravo are staggering.  On trips, which is about all I do, to metro airports, I regularly pay $6.50 to $7.00 as i did this weekend in Manassas.  On the trip home Sunday, I briefly stopped off at Charlottsville to have lunch with one of my sons.  Total fuel burn from Manassas to GNF was 84 gallons.  At $7, that is $588 just in fuel.  In any twin that I would want, the fuel burn would have been three times that; $1,764 for fuel one way.

I'm off the subject.

Thanks for the input.  If I move toward glass in the Bravo, I will send you a PM for updates on your experience.

If you do get a few minutes and are bored, feel free to expound at length on your choice of Aspen and your experience so far.  It would be appreciated.

JG

[Piloto]

John

For extra room I would consider the A36. It burns about he same as the Bravo and can carry six peopple at reasonable speeds. A six passenger MOGAS Mooney would have been an ideal product for Mooney. Hope they would come up with it.

 

José

 

[AndyFromCB]

I don't have much experience with the G500, but here is my take on flying with Aspen. The software is superb, never a crash, slowdown, etc. The hardware has had some infant mortality issues, the service from them was superb as well, less than 72 hours from the moment I notified them of failure to when a new unit was shipped, installed and working. Try that with Garmin. But when it failed, it was a non-issue. Pressed the Rev button on the PFD and all was good again but I lost the ability to display my approach plates in any readable format (screen space). Non issue as the plate was already up on my Yoke mounted iPad, granted, not geo referenced. Since that experience, about 200 trouble free flight hours. I'll snap some pictures of my panel as mine looks funny with 4 attitude indicators (could not remove the vacuum one per Piper Arrow type certificate) and post them but if I ever ended up upside down in the clouds there would be nothing to blame but myself. The truth is, my vacuum gyro has been covered for a while now. I guess it would come in handy in case of EMP attack ;-) Time to go to work.