REFLECTOR: Second First Flight Today

[Brian Michalk]

Unfortunately there was no smoking gun after the first incident.  Like 
carb icing, there wasn't any evidence pointing to a main cause of the 
engine failure.  I did make some modifications, like adding a small 1 
gallon reservoir to serve as a vapor-fuel separator before the fuel is 
returned to the sump.  I also modified my venting system to keep it from 
getting filled with fuel at high angle of attack.

That said, I determined that I had configured the EFI system to be too 
rich.  I tuned the engine to run rich, and extrapolated those values to 
the end of the fuel table, and had never tested the engine at those 
power levels until the first flight.

Words of wisdom:
Make sure you've addressed failure modes as best as possible.  I have 
two battery systems that can power the EFI system.  Then, if all that 
fails, what then?  I also installed a backup constant fuel injection 
system.  It's very simple.  45PSI fuel is taken off the regulated fuel 
rail, and runs up the keel to a needle valve accesible to the pilot.  
 From there it goes back to the engine to spray nozzles mounted in the 
intake manifold.  If the electrics go out, I just turn off all of the 
batteries and continue flying on one magneto and the constant flow 
injection.  There's no metering to adjust to airflow, so it's best if 
set and left alone. Changing the manifold pressure throws the mixture off.

If you go off into the weeds on installing a non-aviation EFI system, it 
really adds a *LOT* of build time.  All of the components are fairly 
simple.  It's getting everything to work properly that's the hard part.

On 3/25/2013 10:52 AM, Glenn Falkenberg wrote:
> Congratulations Brian.  Way to go, your determination is an 
> inspiration to us all.
> I read the account of your first flight on VelocityXL.com. It sounds 
> like your using electronic fuel injection, if so do you feel this was 
> the cause for power loss?  Do you have any words of wisdom for anyone 
> who may be considering this type of system?
> Glenn Falkenberg
>
> On Mon, Mar 25, 2013 at 7:17 AM, Richard J. Gentil 
> <richard at naples-air-center.com <mailto:richard at naples-air-center.com>> 
> wrote:
>
>     Many people would have given up after the cornfield, you did not.
>
>     My hat is off to you, well done!
>
>     Richard
>
>     Sent from my iPhone 5
>
>     On Mar 25, 2013, at 12:01 AM, Brian Michalk <michalk at awpi.com
>     <mailto:michalk at awpi.com>> wrote:
>
>     > Four years ago, I had my first flight on March 28th, which ended
>     up in a cornfield due to an engine out.
>     >
>     > Today, I had my second first flight.  I've been battling a list
>     of squawks, and finally got most of them ironed out.  I made two
>     flights today, with the first one cut short because of high CHT's.
>     I landed and discovered a disconnected colling duct to the plenum.
>     I fixed that, and went for a second flight.  I cut that one short
>     because I thought the smell of smoke was getting stronger.  I
>     think there's some RTV and other materials that are just
>     outgassing, and will make odors until they are good and baked.
>      After that flight, I was just too tired to go up again, and
>     called it a day.
>     >
>     > I still have some issues to address, but the important thing is
>     that now I can actually begin working the flight tests.  I think
>     I'll change my sig to test pilot now.
>     > _______________________________________________
>     > To change your email address, visit
>     http://www.tvbf.org/mailman/listinfo/reflector
>     >
>     > Visit the gallery! www.tvbf.org/gallery
>     <http://www.tvbf.org/gallery>
>     > user:pw = tvbf:jamaicangoose
>     > Check new archives: www.tvbf.org/pipermail
>     <http://www.tvbf.org/pipermail>
>     > Check old archives:
>     http://www.tvbf.org/archives/velocity/maillist.html
>
>     _______________________________________________
>     To change your email address, visit
>     http://www.tvbf.org/mailman/listinfo/reflector
>
>     Visit the gallery! www.tvbf.org/gallery <http://www.tvbf.org/gallery>
>     user:pw = tvbf:jamaicangoose
>     Check new archives: www.tvbf.org/pipermail
>     <http://www.tvbf.org/pipermail>
>     Check old archives:
>     http://www.tvbf.org/archives/velocity/maillist.html
>
>
>
>
> _______________________________________________
> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20130325/40509fe4/attachment-0001.html>