Sunday 20 Sept 2009
1.0 air time
1.1 flt time


Stall and one turn spin testing at mid CG. 75 lb of ballast was well secured in the aft baggage compartment to bring the CG to 82.34" aft of the datum at engine start.


  1. Wings level, turning and accelerated stalls at idle and max power for each flap position.
  2. One turn spins at each flap position (six turn spins with flaps up will be done later, as part of the aerobatic evaluation).


  1. Spins - There is not enough up elevator authority to hold the aircraft in a spin, even at mid CG. The angle and attack and rotation rate are oscillatory, and the airspeed continually increases, indicating the aircraft has transitioned to a full aft stick spiral dive. After seeing the same result in both left and right spins, the right spin was repeated with a longer duration, to see if perhaps the airspeed indication was erroneous, and the aircraft was really in a spin. The spin rate increased, and as the IAS hit about 90 kt, there was a very violent flick to the right, like a snap roll - perhaps the right wing stalled during one of the angle of attack oscillations.

The planned one-third and full flap test points were not attempted.

The up elevator travel will be checked, to confirm that the proper up travel is being achieved.

Existing Snags:

  1. Max rpm still decreases late in the flight.
  2. SD-8 Alternator - must run power wire to regulator.
  3. Small amount of right rudder pedal force needed in cruise. Need to add a wedge on the left side of the rudder trailing edge.
  4. Pitch trim speed of movement is slow during a touch and go. Need to try it with the pitch trim speed governor removed.