The fourth flight on Sunday was similar to flight #3. The goals were to perform full flap testing, and begin stall testing. Prior flights had only used 15 degrees of the 45 available flap degrees. I have flap stops set at 0, 15, 30, and 45 degrees.

Flap testing was uneventful and the flaps perform as expected. Later flights will determine stall speeds at all flap settings. There is considerable pitch down moment when the flaps are deployed and there is considerable sink when retracting the flaps in one continuous motion.

I climbed to ~7,500 feet MSL and performed several approach to stalls with the aircraft in a clean configuration. Post flight examination of the data shows 56.2 KIAS did not stall, but 55.5 KIAS did stall (3rd dip in plot below). Later in the flight I climbed to 10,000 feet MSL.

During flight the seatbelt shoulder harness adjustment was causing the left shoulder belt to get caught on the right side of the seat headrest whenever I leaned to the right. This was annoying so I adjusted it on the ground after flight to prevent this in the future.

Flight #4 Map

Flight #4 Data

Post flight observations:

Right tank dipstick = 8 gallons remaining

Left tank dipstick = 13 gallons remaining

Gauge: L=15, R=12

Totalizer: 18.8 used, 22.2 remaining (41 start)

Engine Time = 1.6, Engine Total Time = 5.8

Time This Flight = 1.7, Total Time = 6.8

Oil = 6.0 Quarts (hot)

Fuel Truck Fill: L = 11.5, Dipstick = 19.5

Fuel Truck Fill: R = 6.7, Dipstick = 20.0

Removed top cowl

Removed wing root fairings (top side only) to inspect the fuel tank inboard ends for any signs of fuel leaking (found none). There was a lot of little dust and debris that had migrated to this location after these first few flights so I vacuumed that out. Expect this came from the wing internals and from under the seat floor pans.

Need to update the checklist to include flaps up after landing, flaps down before shutdown, record flight times before shutdown.

Need to buy and instrument cover for the area behind the instrument panel.