Flight 5 objectives:
- Evaluate performance following installation of snubber fitting and correction of ram air butterfly position
- Complete on-ground and in-flight set-up of autopilot on G3X
- Evaluate pitch control with heavy forward CG
- Calibrate the AOA and perform power-off stalls.
Flight Summary:
Flew two segments, morning and afternoon, with break for lunch, for total of 4.6 hrs. Confirmed correct operation of AP on ground. In flight, verified that snubber fitting and butterfly valve alignment resolved problem of MAP noise. Engage AP and performed in-air set-up to set desired roll and pitch gains. With roll trim centered and a roll gain of 1.0. after a left perturbation of 10deg, the AP rolled level after 10 deg. However, a right 10 deg perturbation required 127 deg before level. Suspecting the roll trim, moving the trim to just left of center, increased the right perturbation recovery speed to 30 deg. Need to reset roll trim neutral position. In afternoon segment added 150 lbs ballast in co-pilot seat and topped tanks. During flight, observed position pitch control at each flap setting and speed from 100 kts to 70 kts.
Performed a few power off stalls and attempted to calibrate the AOA. With full flaps and a heavy forward CG, the plane stalls at about 61 kts. Stall behavior is benign, lots of mushing then the nose drops. AOA calibration was unsuccessful, I think due to inability to maintain level flight. Will try again using the AP. Based on this, Vso of 75 kts is reasonable.
Used Lean Assist to find optimum cruise conditions:
- 23/2300 (66%), 9.2 gpm, 146 kts TAS, lean at peak
- 25/2500 (80%), 11.1 gpm, 155 kts TAS, lean at peak
- 25/2500 (80%). 12.8 gpm, 160 kts TAS, lean 50F ROP
CHTs were all comfortably under 400 F.
Spoke with Aircraft Spruce about ram air control cable. They confirmed stroke should be 3" not the 1.5" I'm seeing. There is likely a kink somewhere preventing full extension. The best option is to remove the cable and test on the bench. A replacement cable will take 4 wks to procure. Also look for a more direct routing with fewer bends.
Engine oil measure 6.8 at start of day and 6.2 at end of day, or 0.13 qts/hr.