I was asked to tear down a plane that had crashed, and find the problem , the FAA and Rotax had inspected the plane and decided it was a pilot problem, the fuel bowls were empty and they were able to bypass all systems and start the motor , I found the FACET fuel pump that was inline to have failed and totally shut off the fuel, one person died because of the crash, DO NOT PUT A PUMP INLINE < PUT IT IN A BYPASS LOOP or leave it out you do not need a boost pump on most aircraft engines , also fly the plane no matter what happens ...BOB   

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Hi Bob

Thanks again for what I think is an interesting discussion. I looked at Facet’s website and their home page has a large disclaimer that their pumps are not approved for aviation use.  I’d like to circle back to your reply to my first post where you said all pumps allow gravity flow in one direction. I do this because it’s related to my question whether you could determine what model number facet pump was installed, because facet sells pumps that have internal check valves that shut off fuel flow when power is removed, and pumps that do not have an internal check valve; rather, they allow fuel flow to continue in either direction when power is removed. What I’d like to verify is did this failed pump come apart internally (did you open up the pump?) or did it quick working due to a power related failure internally and the internal check valve close as designed? I would volunteer to take the pump apart and document what I find if you could send it to me. Thanks!

Jim,we took all that into consideration , even tested the failed pump against a brand new pump of the exact same design , power on, power off, air pressure both ways , this pump came apart internally and plugged its outlet , prior to the crash the pump worked as a boost pump in the system for 150  flight hours ,when only used ,  [ powered up ], for take off / landing , it worked flawlessly in- line until it came apart , I think we are beating a dead horse , forgive the pun , the point is if you are going to bet your life on a automobile pump , put it in a by-pass loop ..BOB 


Thanks for the information. I have a pump in-line and had often thought I needed a bypass of sorts. I’m not flying yet but will add the fix before I do.

Curious if Ethanol gas played a part in causing pump failure

GIL, first of all dont put ethanol in a 912 uls motor and thankfully they dont sell the crap in alaska ..BOB

Bob, I now understand and will be making the modification soon.
Id like to add the pic I've just posted to my plane area here. It is a popular corvair type set-up. What would be the most failsafe, mounting each pump along side each other Y top and bottom?

I really dont know ...BOB

just my opinion but of all the risk assement needed to fly an experimental aircraft, fuel flow is the one I worry about most. I have a set-up with 1 battery , alternator and dual pumps in series as shown in my post.

If you have seen my panel its all electric not a steam gauge in sight ,not needed if flying VFR for precautionary landing.

first flying behind total electric dependent corvair, and now electric fuel dependent O-200.

the builder of my a/c has already complicated things with the 4 way andair valve allowing 48 gals

and now this comes up, Bob many users have set-up like mine can you verify the used pump maybe was different being used in injection type set-up. your fuel filter comment sure peaks my interest

Don't others see the implications made here with this common series pump system?

Im having great fun im my 601XL-B but am always trying to lower lisk to pax and those below

Army aviation "above the best"

Chris. I dont understand the question , the fuel set up we have been talking about is NOT injected ,and all systems should have some sort of filtration , and back -up...BOB 

screens at tank, screen at gascolator and screen at carb is filtration enough for most O-200 installations. Facet makes many pumps as mentioned by others in posts. Is the one you are mentioning the fuel cubes I've pictured? past posts in 601 forum have discussed parallel or series operation BUT never this failure mode you've mentioned ( cept in some filter users posts I see hints) 

I guess what we need to know will the non check valved so called free flow cubes interrupt flow in failure?

After  hours of research here, and at the WW Corvair site I'm going to  defer to Mr. Wynne's testing in the 601 Corvair series pump install. I've looked at NTSB accident reports , as well various user-group comments. They all favor the facet pumps in series ,dual switched . The predominant failures seem to happen in the untried systems. 

The Corvair dual electric series pump has not let my aircraft down for almost 300 hrs and others report longer records. I start on pump A, taxi I switch to B . In flight Emergency Bold Face Checklist includes switch to non used pump.

The same system now also feeds a MA3 carb but now on a O-200

I'm going to have faith I guess as modifying to new system seems to invite more Danger


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