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