REFLECTOR: fuel cap

[David Ullman]

There has been some discussion in the Squadron III news letter about lost
fuel caps.  Seems that there are two issue: 1) cap going through the prop,
and 2) siphoning fuel from both tanks.  The first is easily solved with a
tether system which I will add.  The second is what our rather complex
venting system is intended to overcome, I believe.  In thinking this
through, if a cap comes off, there now low pressure in one tank which could
allow fuel to be siphoned out and draw fuel from the other tank.  However,
the venting system allows air, rather than heavier fuel, to be drawn into
the capless tank minimizing the loss of fuel.  In theory this seems right.
Can someone who has experienced a cap loss confirm this is what happens?

Now have 6 flights on N444DX all with my test pilot Robin Reid at the
controls (co-pilot on the Pipistrel G4). Aileron problems seem to be
resolved.  It has rained here solidly for the last 2 weeks (10+ inches, the
drought is over!! - a NW joke) so no more progress on that front.

David Ullman
N-444DX Velocity 
EAA 292 President
david at davidullman.com
541-754-3609