RV-8 Project N804PT

Flight Testing

November 28, 2007: First test flight. Basic airworthiness confirmed. Beginning hobbs time .2 (taxi tests). End hobbs time 1.1 for .9 flight duration.

Pilot's test flight report: Because ground runing times need to be minimized until the engine is broken in, the maximum power check was conducted on the runway. The throttle was advanced looking for approximately 2700 prop RPM. Since the RPM stabilized at between 2690 and 2700, the brakes were released and throttle advanced to full open. The airplane lifted off in the three point attitude, and a slight pitch down resulted in a 100 knot climb. With just a touch of elevator trim, the airplane was climbing dead straight ahead hands-off. A left turn was initiated, and the rest of the flight was conducted at 2000 ft (1400 AGL) in an orbit above the GPM airport. A power reduction to 2500 RPM and 25 MAP resulted in a stabilized indication of 160 knots. CHT's were all between 330 and 360, with EGT's 1300 to 1325, oil pressure 70 psi, and oil temperature 178. After about 25 minutes of flight time, the aircraft was slowed to 60 knots, then brought back to 160 knots. Next, the flaps were extended approximately 20 degrees as the aircraft was again slowed to 60 knots, followed by flap retraction and resumption of cruise speed. A low approach to the runway was flown next, with a normal pattern and landing following. The highest recorded CHT during the flight was 375 degrees, and the highest recorded oil temp was 186 degrees. Both of these temperatures were noted during slow flight, and both recovered when normal speed was resumed. The only squawks noted during the flight were a calibration error in the fuel pressure and a loose cowling fastener found on the postflight. Very successful first flight!

December 3, 2007: Second flight. Confirmation of first flight findings. End hobbs time 1.7 for .6 flight duration.

December 3, 2007: Third flight. Validation of engine reliability. Checkout of engine controls and observation of engine parameters. End hobbs time 3.0 for 1.3 flight duration.

December 4, 2007: Flight 4. Confirmation of left auxiliary tank fuel transfer. Takeoff was made on the right fuel tank. After climbing to a safe altitude, fuel selector was switched to the left tank, and the 2 gallons of fuel in the left auxiliary tank was burned off with no abnormal fuel flow or fuel pressure indications. End hobbs time 3.9 for .9 flight duration.

December 6, 2007: Flight 5. Confirmation of right auxiliary tank fuel transfer. Takeoff was made on the left fuel tank. After climbing to a safe altitude, fuel selector was switched to the right tank, and the 2 gallons of fuel in the right auxiliary tank was burned off with no abnormal fuel flow or fuel pressure indications. End hobbs time 4.8 for .9 flight duration.

December 7, 2007: Flight 6. Confirmation of left auxiliary tank fuel transfer for takeoff. Takeoff was made on the left fuel tank, with 2 gallons of fuel in the left auxiliary tank. There were no abnormal fuel flow or fuel pressure indications. End hobbs time 5.8 for 1.0 flight duration.

December 7, 2007: Flight 7. Confirmation of right auxiliary tank fuel transfer for takeoff. Takeoff was made on the right fuel tank, with 2 gallons of fuel in the right auxiliary tank. There were no abnormal fuel flow or fuel pressure indications. End hobbs time 6.6 for .8 flight duration.

December 13, 2007: Flight 8. Confirmation of adequate fuel flow for takeoff with the right main tank full. Takeoff was made on the right fuel tank, with the tank completely topped off. There were no abnormal fuel flow or fuel pressure indications. End hobbs time 7.5 for .9 flight duration.

December 13, 2007: Flight 9. Confirmation of adequate fuel flow for takeoff with the left main tank full. Takeoff was made on the left fuel tank, with the tank completely topped off. There were no abnormal fuel flow or fuel pressure indications. End hobbs time 8.3 for .8 flight duration.

December 13, 2007: Flight 10. Confirmation of adequate fuel flow for takeoff with the right main tank full and fuel in the right auxiliary tank. Takeoff was made on the right fuel tank, with the tank completely topped off and two gallons in the right auxiliary tank. There were no abnormal fuel flow or fuel pressure indications. End hobbs time 9.2 for .9 flight duration.

December 13, 2007: Flight 11. Confirmation of adequate fuel flow for takeoff with the left main tank full and fuel in the left auxiliary tank. Takeoff was made on the left fuel tank, with the tank completely topped off and two gallons in the left auxiliary tank. There were no abnormal fuel flow or fuel pressure indications. End hobbs time 10.0 for .8 flight duration.

December 17, 2007: Three touch and go's to warm up the engine. End hobbs time 10.3 for .3 flight duration. Following this flight, the engine oil was drained and the Ryton sump was changed for the new Superior all aluminum sump. At this time, the aircraft was given an inspection very similar to an annual condition inspection. All of this work grounded the airplane for a couple of weeks.

January 1, 2008: Flight 12. Stall, stability and spin testing. Stalls and slowflight tested; flaps 0, flaps 20, and flaps 40 - very conventional, with strong buffet and no wing drop tendancy on primary stall (secondary stalls did tend to cause a wing drop). Stability tested - strong, stable short period longitudinal stability, conventional phugiod; strong directional stability; slight but not difficult spiral instability. Spin testing - left and right spins are very conventional tested up to two turns. End hobbs time 11.8 for 1.5 flight duration.

January 1, 2008: Flight 13. Accelerated stall and limit testing. Accelerated stalls have a very strong, almost violent buffet (a well known RV-8 charicteristic), but are otherwise conventional. Positive load limit testing produced no anomalies. Airspeed tested up to Vne. Aileron rolls to left and right sprightly and conventional. End hobbs time 13.6 for 1.8 flight duration.

January 2, 2008: Flight 14. Aerobatics testing. Inverted flight for up to two minutes continuous tested. Loops, immelman turns, split-S's, hammerheads left and right, and rolls left and right all very conventional. Spins left and right are very conventional tested up to three turns with no more than 1/4 turn required for recovery. End hobbs time 14.7 for 1.1 flight duration.

January 2, 2008: Flight 15. Climb and glide performance testing. End hobbs time 17.0 for 2.3 flight duration.

January 3, 2008: Flight 16. Expanded CG (20% further aft) testing. Stability and stalls very similar to earlier tests. Spins performed up to three turns each direction - require more positive recovery technique at this CG. Snap rolls left and right as expected. End hobbs time 18.3 for 1.3 flight duration.

January 3, 2008: Flight 17. Expanded CG (40% further aft) testing. Stability and stalls very similar to previous test. Spins performed up to two turns each direction. End hobbs time 19.8 for 1.5 flight duration.

January 7, 2008: Flight 18. Expanded CG (60% further aft) testing. Phugoid period starting to be longer - still very stable. Stalls have more break at this CG, but still very straight forward. Spins performed up to two turns each direction. GPS approach modes tested good. End hobbs time 22.2 for 2.4 flight duration.

January 7, 2008: Flight 19. Expanded CG (80% further aft) testing. Short period longitudinal stability adequate but noticeably degraded. Phugoid very long period but still stable. Latereal stability still good. Spins performed up to two turns each direction - multi-turn spins beginning to show signs of flattening out at this CG. End hobbs time 23.3 for 1.1 flight duration.

January 8, 2008: Flight 20. Maximum aft CG testing. Short period longitudinal stability becomming marginal. Phugoid about the same as previous. Latereal stability still good. Stalls still show adequate warning buffet, but sharper break. Practice GPS approach with missed aproach and holding entry at KSEP- system working properly. End hobbs time 25.1 for 1.8 flight duration.

 

 

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