ON JULY 12, 2022 at approximately 8PM, N321CX took flight for the first time. After successful FAA inspection in the morning, reinstallation of all inspection covers and fairings, complete reinspection and cowling installation, we prepared for first flight.
Start up was normal and we let the engine run on the ground for a period of time to make sure all seemed good. Let the oil temperature warm up which did not take very long given that the outside temp was close to 90 degrees. Winds were stronger early in the day and were predicted to decrease toward evening and that is what happened which provide a perfect opportunity to fly the plane.
I don't know about anyone else that has performed a first flight on a plane they built but there was a lot going through my mind. What if the ending quits? Where would I land? Would I try a turn around maneuver? What if a flight control did not work properly? What if, what if, what if? I knew that I was a capable pilot and that I could handle the plane if all things lined up and worked properly but there was still a lot on my mind.
Once the runup was complete, I pulled onto the runway and took a deep breath and advanced the throttle. Shortly after reaching full power, there was a significant surge from the propeller so I aborted the take off. Rudder control in this circumstance was excellent and I back taxied and returned to the run up area.
I did an additional runup and cylced the propeller and all seemed normal. I again announce my intentions to depart and pulled on the runway. As I advanced the throttle, the engine was smooth and there was no surge from the propeller and before I knew it, I was airborne. It was the "before I knew it" part that bothered me after the flight. I always believe that flight should be intentional but with all that was going through my mind and everything in the green, I was flying, albeit slightly ahead of my intention.
The plane felt solid and controllable with no obvious roll or pitch issues. Airspeed was indicating about 85ikts and I did not observe the rate of climb but shortly after starting the climb, the CHTs on 1,3,and 4 all spiked to over 440 degrees and that alarmed me. I immediately radioed the ground crew and told that my intention was to reduce power and level off at 1300 ft. Reducing power to 16 inches and remaining level, I was able to keep the CHTs from continuing to climb but they did not reduce either.
The flight plan card for the first flight called for a reversing 180 at 2000ft AGL and then a climb to 5000 AGL to get a feel for the plane, practice a couple landings at altitude and then bring it home. Since the ending is new, we really wanted to run the engine hard for at least 1 hour but with the CHTs the way they were, I decided to land and airplane that I had never landed before nor had I explored the stall and slow flight.
In the end, I relied on my instinct around how the airplane "felt" and kept the IAS below 80 for flaps and gave myself plenty of time on final. After circling the field 1 additional time after the first circuit, I set up for downwind. Added first position flaps and then turned base and added second position flaps. Flew the last part of the final at about 75kts which "felt" right. The landing happened, again, slightly before I was ready and there was a small bounce that was tamed with aft stick and the rollout was uneventful.
CHTs immediately reduced at the lower throttle settings and taxiing back was good. After shutdown and moment of reflection in the cockpit, we celebrated our achievement. Now it was time to figure out why the CHTs were so high and if that was, in fact, an issue.