Post inflight Vacuum pump failure - fly?

[TargetDriver]

Hello All.  I've been quietly soaking up Mooney knowledge from your great site for some time. Last week I finally did it ! I bought a '80 M20K and made the 3.5 hr flight from Minnesota to Missouri, then on to California in a single day of 10.5 hours of fun... that ended with an hour of concern but thanks to my new 231's back up vacuum pump system, we got home safely. While in VFR flight following I lost the vacuum pump over the Sierra's at 10.5K ft in the dark.  No other indication than a panel warning light and lost the ADI. We had just did a very detailed pre-buy and annual before leaving but I guess the Vacuum pump just ran out of hours (500 I hear is about the life) . Checking the log books now for some indication of vac pump hours since last.

My question is this. I'll tear into the plane next weekend to check the pump, regulator and filter but is the plane safe to fly as is? Obviously not in IFR conditions, but is there a risk to further damage maybe an input shaft, send FOD downstream , etc ?  If I switch on the backup, which I presume is electric, the system come right up. Is the backup capable of being ran occasionally, or is it only for short-run backup usage?

Thanks all for your info and I'm looking forward to spending many hours making my way into the Mooney club!

Thanks

[bonal]

Let me be the first to welcome you and congratulate on you new K as for the question I am not qualified to respond as I don't know the regs if there is an alternate vacuume source. My question is why you would want to risk it knowing you need to restore your primary. Good luck with the repairs and would like to see some pics of the new Mooney

[N201MKTurbo]

I wouldn't leave on a cross county with a failed pump, but I would fly it home if I was out of town or to another airport to get it fixed. I have flown from KHIO to KCHD with a failed pump. Luckily I have an electric backup so my autopilot still worked. That is the worst part of a failed pump in VFR.

If the shaft is sheared, nothing evil can happen to your engine.

[DrBill]

As I posted earlier, my pump failed c30mins into a 2.6hr engine breakin flight.   I too have stanrdby vacuuum but elected not to use it

since it was severe clear I continued and actually flew a pair of approaches before returning to home airport.

The drive failed (pics in my post). 

New pump going in tomorrow.

Bill

 

[RLCarter]

I know you can fly day VFR with a failed vac. system, but I don't think you can legally fly night VFR with it in-op. As far as flying with the stand-by (electric driven) pump , I woulld say that it's a no go, there should be a supplement to you POH/AFM about the stand-by sytem. 

Poh, congrats on your purchase

[Guest]

1 hour ago, DrBill said:

As I posted earlier, my pump failed c30mins into a 2.6hr engine breakin flight.   I too have stanrdby vacuuum but elected not to use it

since it was severe clear I continued and actually flew a pair of approaches before returning to home airport.

The drive failed (pics in my post). 

New pump going in tomorrow.

Bill

 

Bill,

Engine "break in" flights don't normally include approaches.  The idea is supposed to be higher power (75%) operations to help seat the rings and cylinder walls.

Clarence

[chrisk]

15 minutes ago, RLCarter said:

I know you can fly day VFR with a failed vac. system, but I don't think you can legally fly night VFR with it in-op. As far as flying with the stand-by (electric driven) pump , I woulld say that it's a no go, there should be a supplement to you POH/AFM about the stand-by sytem. 

Poh, congrats on your purchase

I'm certain you can fly night VFR with out a vacuum pump.   You need to add External lights (anti collision and position) and sufficient battery / generator / alternator to drive them.  You do need to see a horizon to stay safe!

[Immelman]

I used to be of the mindset that it would be OK to fly it. But I think I expressed this thought and someone had a comment I found hard to ignore: The failed vacuum pump is bolted on to your engine's accessory case, correct?

That alone is reason enough to ground it unless you can prove there is no chance in hell anything will come back in and contaminate your engine, or some seizure would occur that would jam your accessory gears....

Edited February 29, 2016 by Immelman

[N601RX]

The last 3/4" or so of the vaccum pump drive shaft is connected to the rest of the pump with a plastic drive coupler that will shear off disconnecting the pump from the accessory case gearing. 

[Loogie]

TargetDriver, at this point your aircraft is degraded, you are on a "Back Up" system.  Safe to fly? VFR day yes, but only if you have to in order to affect the repair. At that point, ground your machine and get it back to a non degraded condition.  If you can repair where it's at, ground it until you have fixed it.

It is a thought process, and a disciplined approach to safe aviation.  Acceptance of risk and getting away with it can lead to bad decisions in the future; only you can decide how to approach what is operationally acceptable or not.  Where do you draw the line, everyone has a different level of risk acceptance.  Good Airmanship also applies to good common sense approach as to what is acceptable or not.  

My .02cents

 

[DrBill]

59 minutes ago, M20Doc said:

Bill,

Engine "break in" flights don't normally include approaches.  The idea is supposed to be higher power (75%) operations to help seat the rings and cylinder walls.

Clarence

Right, after the first 2 hrs (1 hr at 75%) and the 2nd at 65/75% alternating,   We went for a short trip so I could do a couple to get current.  I normally do 3 every 3 mos. so I've got 1 more to do.  We spent 2 hrs over my airport at 4700 ft watching all  kinds of commercial traffic go by high and low with flight following.And getting ads b warnings.   It was fun doing them at no less than 50% .. Makes for a quick trip.

Bill

 

[DrBill]

10 minutes ago, N601RX said:

The last 3/4" or so of the vaccum pump drive shaft is connected to the rest of the pump with a plastic drive coupler that will shear off disconnecting the pump from the accessory case gearing. 

look at my post in the vintage area, it has a picture of the sheared coupling.

Bill

 

[carusoam]

From an engineering point of view.  It would be good to know what failed.  The carbon pump blades have a tendency to disintegrate. Bits of carbon can be brought toward the lowest pressure point in the system. There may be carbon bits sitting in a filter near the instruments.  

A vac system drawing is in the POH.  You should be able to see the risk of carbon dust moving towards the expensive devices.

It could get more expensive if a filter doesn't work as planned.

I am only a PP, not a mechanic.

Best regards,

-a-

[Bob]

Here is the supplement for the stand-by vacuum pump.  May answer a couple questions?

http://www.mooney.com/en/pdf/StbyVac_RevG.pdf

[TargetDriver]

Guys, Thank you all for your welcome, replies, and the great advice. I thought I was going to have to fly it to have it repaired but it turns out that I will most likely be able to have it repaired at my new home field.  I went through the logs today and as best I can tell, the pump is 7 1/2 yrs old and has 456 hours on it...  so, yep ...500 hour life! The engine only has 300 hrs on it after a major and the turbo system has less than that.  I suppose the accessories obviously have a lifespan of their own.  I pulled the top cowling off and its the 215CC pump, so a new one looks like $355... a small price to pay for piece of mind, even if it would only be a sheared shaft. I'll order a new one tomorrow, along with a new filter.

[TargetDriver]

I am much more likely to spend the extra money for the new vacuum pump, is there a reliability or lifespan difference in the reman unit versus a new one ? 

[chrisk]

12 hours ago, Loogie said:

TargetDriver, at this point your aircraft is degraded, you are on a "Back Up" system.  Safe to fly? VFR day yes, but only if you have to in order to affect the repair. At that point, ground your machine and get it back to a non degraded condition.  If you can repair where it's at, ground it until you have fixed it.

It is a thought process, and a disciplined approach to safe aviation.  Acceptance of risk and getting away with it can lead to bad decisions in the future; only you can decide how to approach what is operationally acceptable or not.  Where do you draw the line, everyone has a different level of risk acceptance.  Good Airmanship also applies to good common sense approach as to what is acceptable or not.  

My .02cents

 

 

For me this is overly conservative.   The FAA is very clear on what is required for VFR flight (day or night) and a DG or artificial horizon are not required equipment.  I've flow plenty of planes (day and night) that were not equipped with an artificial horizon or DG.   I'd feel very comfortable flying this plane in VFR conditions and would have no concerns flying it back to my home field where I could get it repaired by a trusted mechanic.  That said, one should pause and consider the consequences of not having the equipment working.  It would be wise to avoid flight where a real horizon was not clear. 

And for those that think I am throwing caution to the wind, what would you do if the TKS in your FIKI Mooney wasn't working.  --For most of us, we don't have TKS and we wouldn't worry about it flying a plane where TKS didn't work.  For those who do have FIKI plane, most would avoid flight into known icing with a broken system.   And I suspect very few of us would ground the plane until it was fixed.   --It's the same as a vacuum pump going out.  Stop and evaluate what it means.  Limit your flight envelope based on reduced capabilities.  It doesn't mean ground the plane.

[carusoam]

Flying my plane for years and having something fail...

vs.

1) Flying a plane that I just got

2) Just came through annual

3) flying at night

4) overhaul vs new vac pump

5) flying using a back-up system because the primary failed.

Sounds like small additions of small risks on top of the risk of taking on a new to you aircraft.

Consider taking steps to systematically eliminate these risks.

Avoid gaining additional risk when possible.  Take them on when you know the risk and are willing to take the risk.

These are just my PP thoughts being shared.

What would Chip Ganassi think of adding small risks instead of eliminating them?

(Chip Ganassi is the guy that hires Target drivers of note)

Best regards,

-a-

[TargetDriver]

Ha ha  R.really liked the Chip Ganassi Target driver reference !  I've driven sand dragsters to alcohol top dragsters and funny cars... but I'd give one of my *** to crawl in one of those Target cars!  I fly military targeting aircraft...hence targetdriver.     So after weighing the issue I am sure I could have flown the plane w/o the DG or AI and would have been in VFR but not being 100% knowledgeable on the Conti accessory case and its mounting configuration, as to whether or not there could possibly be any passage of debris or FOD into the  engine, I decided not to fly it until I put on the new pump. Ordering today. 

I've got plenty of engine/mechanical experience but just not sure about this particular application.  Now I guess my biggest dilemma is to have to pay an A&P to simply R&R that very basic 4 bolt pump. Ha  ..time to finish that A&P tag I guess.

 

[N601RX]

15 hours ago, TargetDriver said:

I am much more likely to spend the extra money for the new vacuum pump, is there a reliability or lifespan difference in the reman unit versus a new one ? 

Look at the Tempest 3000 units.  They advertise 1300 hrs and have a sight port so you can monitor wear.

[BDPetersen]

Carusoam's concern is a good one. The theory is that debris from internal pump failure is drawn in by the slight suction created by the spinning down gyros. The question is what happens when a standby system is added to the mix. Concern for the health of the gyros should be a factor.

[markejackson02]

The vacuum pump is cheap (relatively) and easy to replace.  I would fly home without it but wouldn't fly off on a new trip without it.

[Mark89114]

There is a filter between the vacuum pump and the gyro instruments to prevent failed pumps from contaminating the expensive stuff, at least there is on my ovation.  

[TargetDriver]

I ordered a new Rapco unit and a new inline filter as well.  The warranty seems good as well for this one. I'm certain I'll run out of time before the hours.  "3 years, 1300 hours from date of installation or 4 years from date of manufacture whichever comes first.".

Being the curious type, I'll cut the inline air filter apart  liek we do oil filters, just to see if there is any minute particles that would have made their way to the gyros.

 

[jetdriven]

the CV1J4 filter doesnt need to be cut, you can see inside it.