Good News:  Velocity N755V received FAA airworthiness certification
yesterday.  Also survived an intensive 4-hr inspection by a factory
authorized insurance inspector with a small list of minor items to attend
to.

 

Not So Good News:  Main issue now seems to be cooling during ground
operations, particularly oil cooling, and the secondary temporary issue of
mixture reprogramming (again, after software update).  With the wing root
cooler in a pusher configuration there is almost no oil cooling when
standing still.  So running at significant power to adjust mixture allows
little time to do anything before reaching temp limits. Then, with cowl on,
it takes hours for it to cool down.

 

My expectation was for enough natural convection cooling on the ground to
handle low power taxi operations.  Earlier static running suggested that
there would be sufficient time, but I'm finding that; a) taxi maneuvering
with brake steering takes more power than anticipated, and b) the 3" thick,
16 fins/in. oil cooler core has almost no natural-convection cooling. Have
no good ideas at the moment how to improve this situation.  Haven't gotten
to high speed taxi yet to see if temps stabilize.

 

Tracy; can you tell me the basics of your water spray system?

 

The in-cowl coolant rad gets reasonable air flow because of negative
pressure generated by the prop aft of the cowl.

 

More later,

 

Al