I've never been certain that my zero flap position (aligned with the
fuselage
strakes) was the proper one for best performance. Paul Lipp's email got me to
thinking about it.
 
  Here's what I did:
 
  1. I adjusted the flaps so that they would reflex well above the strakes.
  2. I decided not to get a digital level.
  3. I flew a constant power, steady altitude, at what I consider to be an
average gross weight and a typical high altitude indicated airspeed.
  4. I bumped the flaps up and down, letting the airplane stabilize before
making the next change. I noted the change in indicated airspeed at each flap
position.
  5. The result: Flaps aligned with the fuselage strakes (Lancair 320 Mk II)
gave me the best performance.
 
  Any comments? What did I miss by not using the level?

Bill,

 

The level is not important unless you are interested in the AOA changes.  I am sure you either trimmed out the pitch changes or let the AP do it.  It is note worthy to experience the pitch/trim change delivered by very small deviations from the faired-in position (300 series Lancairs). 

 

With flaps set in a downward displacement (increasing lift/drag), the required nose up trim increases the negative lift of the horizontal stab - perhaps adding more drag.

 

With flaps more highly reflexed, the design limit of drag reduction may have been met.  Nose down trim should have unloaded the tail a bit but there has got to be an optimum combination - on your plane, with its wing and horizontal stab incidence, the optimum was reached at the faired in position, just like the designer planned it.

 

Thanks for the info.