I need a backup AI

[neilpilot]

Vacuum independence is a major reason I prefer sTec autopilots.

[Marauder]

I already said from the start that I have one but it doesn't help my deployment capability when I gotta depart IFR or at night with a broken vac pump.

Mike -- I'm with you on the usefulness of the Precise Flight Standby vacuum system. I considered it an emergency tool and not something I would want to be caught on flight where I needed to fly for some time to get to an airport. In order to obtain adequate vacuum, you really needed to pull the power back. Here is the power/vacuum matrix I created years ago when I had the system.



When I had the Aspens installed I removed it. There are a ton of good alternatives that were available back in the 90s. Well, maybe I should say, reasonably priced solutions back in the 90s. A J owner here installed one and by the time you add labor and cost of the Precise Flight, you are half way to a G5.


Sent from my iPad using Tapatalk

[LANCECASPER]

20 hours ago, 201er said:

This is already my 3rd vac pump failure in just over a year. 

This is a long shot but you don't happen to be turning the prop by hand when moving or positioning the airplane? Turning it even a little the opposite direction will take out a vane. I suppose the same could happen if it back fired.

[RobertGary1]

No, something else is wrong. I'm on my 3rd in 20 years. There must be some contaminants getting into the pump. Even small amounts of oil mist, etc will damage them.

Personally I don't consider Precise Flight to be much of a back up. I've not found the gyros themselves to be much more reliable than the pumps and Precise Flight only addresses 1/2 the equation. For me the G5 is the best solution. Move the old AI as a backup.

 

-Robert
 

[201er]

16 minutes ago, LANCECASPER said:

This is a long shot but you don't happen to be turning the prop by hand when moving or positioning the airplane? Turning it even a little the opposite direction will take out a vane. I suppose the same could happen if it back fired.

I can't swear that the prop was never turned backwards. But my SOP is turning it forward like I'm hand propping to get out of the way just in case.

3 minutes ago, RobertGary1 said:

No, something else is wrong. I'm on my 3rd in 20 years. There must be some contaminants getting into the pump. Even small amounts of oil mist, etc will damage them.

Could be they don't make them like they used to lately? One common thing is that all 3 come from the same supplier as I'm doing it through my usual mech. Still having trouble getting them to honor their warranty. But I'm stuck getting the same junk so that warranty could cover it.

[Mr Bill]

Mike,

Have you considered an Airwolf Wet pump? They are a modern version of the highly reliable Pesco wet pump. Airwolf has all the paperwork for bolt in replacement.

Regards, Mr Bill

[LANCECASPER]

9 minutes ago, Mr Bill said:

Mike,

Have you considered an Airwolf Wet pump? They are a modern version of the highly reliable Pesco wet pump. Airwolf has all the paperwork for bolt in replacement.

Regards, Mr Bill

Looks like a great product

http://www.airwolf.com/aw/products/airwolf-wet-vacuum-pumps

[RobertGary1]

17 minutes ago, LANCECASPER said:

Looks like a great product

http://www.airwolf.com/aw/products/airwolf-wet-vacuum-pumps

From the website it seems like no more difficult than swapping dry pumps. But that leaves open the question of where the oil comes from / goes to. I assume it must go inline with the cooler hoses in the back of the engine.

-Robert

[ArtVandelay]

Looking through my logs, the first vacuum pump replacement was at 1009 hours, then 2 more at 1033 and 1060 hours. The 3rd also mentioned replacing hoses from regulator to filter, after that there was no problem.

[neilpilot]

1 hour ago, RobertGary1 said:

From the website it seems like no more difficult than swapping dry pumps. But that leaves open the question of where the oil comes from / goes to. I assume it must go inline with the cooler hoses in the back of the engine.

-Robert

I seem to recall there was someone on MS who decided to remove a wet vacuum pump, due to constant and excessive oil residue on the belly.

[brad]

I had 3 failures - each at around 70 hours.  Installed an electric AI as backup.  What really solved the problem was the Airwolf wet VP.  1200 hours and not an issue.

[Marauder]

These wet pumps work great. The rap on the older version is the amount oil spewed during usage. Looks like they are recommending the usage of an air oil separator.


Sent from my iPad using Tapatalk

[bradp]

The century IIb requires input from the AI- so no AP if the pump fails.

My only failure was from what I'd describe as severe turbulence. It was enough to shear the shaft.

I'd suspect you have graphite in your tubing somewhere. Tubing needs to be cleaned out or replaced after a pump failure- you can't just bolt on a new one. Filter should really be replaced at the same time.


Sent from my iPhone using Tapatalk

[RobertGary1]

Rate based autopilot vs roll. The stec are on the turn coordinator but are rate based so they bounce more in turb

 

 

 

[Guest]

Three failures with so few hours suggests something else being wrong.  I've seen a pump shear the plastic drive coupling, yet when I opened it up the rotor and vanes were fine, but could not be turned, not your typical failure mode.

Clarence

[RobertGary1]

2 hours ago, M20Doc said:

Three failures with so few hours suggests something else being wrong.  I've seen a pump shear the plastic drive coupling, yet when I opened it up the rotor and vanes were fine, but could not be turned, not your typical failure mode.

Clarence

My last failure did that. Shaft snapped for no reason. Rotor spun fine and vanes were fine. Spun fine on a drill Previous failures were all seized veins.   

-Robert

[Daniel Low]

Looks like a great product
http://www.airwolf.com/aw/products/airwolf-wet-vacuum-pumps

This is what I have. I installed it about 10 years ago and no issues whatsoever. It pays for itself by not requiring repeated replacements and the peace of mind of not having a dry pump.


Sent from my iPhone using Tapatalk

[Daniel Low]

These wet pumps work great. The rap on the older version is the amount oil spewed during usage. Looks like they are recommending the usage of an air oil separator.


Sent from my iPad using Tapatalk

Correct. I have no oil leakage.


Sent from my iPhone using Tapatalk

[flyboy0681]

Scary stuff with expensive alternatives.

Last weekend I went under the hood for 1.1 hours. Of those 1.1 hours I had the AI covered for 1.0 hours. I've always done fine without it in all of my training, but have no idea what I'd be up against if it happened in IMC.

[carusoam]

Consider IMC with real bumps....

the kind of bumps that make the TC get hard to use.

Some TCs would be really hard to use under these conditions.  

A reminder to Try to get a feel for the TC when in really bumpy conditions... no hood required for this.

Best regards,

-a-

[flyboy0681]

Just now, carusoam said:

Consider IMC with real bumps....

the kind of bumps that make the TC get hard to use.

Some TCs would be really hard to use under these conditions.  

A reminder to Try to get a feel for the TC when in really bumpy conditions... no hood required for this.

Best regards,

-a-

Good reply. It was a hot weekend down here and we were definitely getting bumped around. My frustration of relying on the TC was quite noticeable to my partner.

[jetdriven]

On 2/7/2017 at 11:51 AM, flyboy0681 said:

Scary stuff with expensive alternatives.

Last weekend I went under the hood for 1.1 hours. Of those 1.1 hours I had the AI covered for 1.0 hours. I've always done fine without it in all of my training, but have no idea what I'd be up against if it happened in IMC.

Treat it like an emergency situation, because it is. A lot of pilots lose control and crash. A second AI mitigates this substantially.

[Daniel Low]

Consider IMC with real bumps....
the kind of bumps that make the TC get hard to use.
Some TCs would be really hard to use under these conditions.  
A reminder to Try to get a feel for the TC when in really bumpy conditions... no hood required for this.
Best regards,
-a-

I replaced my turn coordinator with a second AI many years ago, an electronic one from RC Allen. It has been 100% reliable. I would recommend all 6-pack pilots replace their turn coordinators with an electronic AI.


Sent from my iPhone using Tapatalk

[Chris from PA]

Sandia Aerospace 340 Quattro. Electric, battery back up, fully certified as a primary attitude reference instrument. I would think you could mount one as a backup in your panel and be completely legal to fly in IMC.  

[peevee]

On 2/7/2017 at 10:09 AM, Daniel Low said:

This is what I have. I installed it about 10 years ago and no issues whatsoever. It pays for itself by not requiring repeated replacements and the peace of mind of not having a dry pump.


Sent from my iPhone using Tapatalk

there was a thread a few months ago on them, it's the first I had heard of them, I don't know why. They sound fantastic.