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Friday 25 Sept 2009
2.4 air time
2.5 flt time
2.6 hrs to go to finish the official flight test phase

Inter-flight activities:

  1. Added more ballast to the passenger seat to bring the CG to 85.1" aft of the datum. The CG moved further af to the aerobatic aft CG limit (85.3") as fuel was burned. Weight at engine start was 1803 lb, the highest weight that has been flown to date.

Purpose:

  1. Stalls and one turn spins at aerobatic aft CG.
  2. AWM 549.111 climb performance test (amateur-built aircraft in Canada must demonstrate the ability to climb 1000 ft in 3 minutes, at max take-off weight, corrected to sea level, standard day conditions).

Events:

  1. Wings level, turning and accelerated stalls at idle and max power for each flap position.
  2. One turn spins in each direction with flaps up (six turn spins with flaps up will be done later, as part of the aerobatic evaluation). The planned one turn spins with flaps extended were cancelled due to the significant risk of flap overspeed, and the likelihood that any in-service spins with flaps extended would likely occur at too low an altitude to allow a recovery.
  3. Trimmed at VNE, then landed without retrimming. The trim angle will be measured, and the pitch trim will be adjusted to achieve this angle at full nose down travel. Reducing the nose down trim travel will increase the nose up trim travel, which will reduce the stick forces during final approach at forward CG.
  4. Recorded full throttle MP vs IAS at 7500 ft.

Results:

  1. Stick free longitudinal static stability is still positive at idle power, but is noticeably negative at low speed at maximum power at all flap settings. If the aircraft is trimmed at 80 kt at full power, forward stick force is required as the speed is reduced without changing the power. If the speed is reduced from the trim speed, and the stick is released, the speed continues to reduce until the aircraft stalls. Positive forward stick pressure is required to recover from the stall.
  2. Stick force during approach and landing with trim at the position for VNE was less than 5 lb.
  3. Post-flight analysis suggests that the induction system is achieving about 2/3 of the theoretical maximum amount of ram air pressure recovery, which is surprisingly high.

New Snags:

  1. Rubber sealing strip between the left wing intersection fairing and the fuselage came loose, again. Tape will be used on the bottom of the intersection fairing to attempt to hold the sealing strip in position, without resorting to the glue that will be used once the aircraft has been painted..

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.