wrote:
X-No-Archive: yes
pretty thorough explanation

Hmm... neat! thanks for answering my question so well. It would
seem to me that you really did your homework. In particular I like
the idea of drawing from the side, instead of the bottom, of the sump.

At first glance I wondered why you chose to use a separate pump for
your heater design. I figured it would be better for the heater flow
to piggyback off the engine's normal flow (same as coolant based
heaters). But I see the wisdom in your setup isolating the heater
with it's own positive pump. As you said, the normal failure mode is
no cockpit heat for the rest of the flight and the loss of less than
a critical amount of engine oil.