First Flight Analysis

This post is my debrief of my first flight experience that I’m hoping will be helpful for other builders and first-flight pilots.

First, the buildup to first flight will be unique to every builder. For me, I was ready for awhile (almost 2 months since airworthiness inspection) and was basically waiting for a day for both weather and personal/family schedule to align. I didn’t want to “set a date” for the first flight with a big party and lots of guests only to have that date arrive with less than ideal weather, resulting in either feeling like I’d let people down, or feel pressured to fly when I wasn’t comfortable. I know a lot of folks wanted to be there and I wish they were, but when the day came I was internally grateful to be able to focus purely on the task at hand.

And so, that day finally arrived, we had the weather forecast turn from abysmal to nearly perfect on a free morning and pulled the trigger the day before the flight.

I had basically 2 main concerns prior to my first flight.

The first, which will be on the forefront of the mind of every first flight pilot, was the engine. I didn’t have doubts that the engine would perform, but I was having above-average oil pressures on my ground runs and several points on the engine that had some oil seepage, all of which I had investigated thoroughly and determined that there were no obvious faults, the engine simply needed to be broken in, which meant running it in flight with proper cooling.

The second was landing a tail-wheel aircraft. I have 4500+ hours of flight time, ATP, Commercial, Instrument, Multi-engine and even a seaplane rating from many years ago. Most of my time is as a professional pilot but I had logged only 2 hours of tail-wheel time including my tail wheel endorsement/training in a Citabria and Decathlon. My tail-wheel instructor told me I was doing a great job but I never felt that my landings were on par with my landings in conventional-wheeled aircraft. I had done a flight in a Sonex at the factory when I bought my kit (I felt very comfortable with it immediately during our 30 minute flight) but that flight was not in a tail-wheel either.

On to the first flight… the plane was ready to go in the hangar and I knew it, so when we arrived it was just a matter of doing a standard preflight check, putting on the cowling and filling it with fuel. I was glad to get an engine start and short taxi in to the fuel pumps both to get out some initial butterflies and to get some heat into the engine.

The taxi and takeoff were relatively uneventful, there was traffic in the pattern on downwind as I finished my runup, which actually helped me to focus when I knew the checklist was done and the plane was ready to fly.  The taxi to the end of the runway was a mile long and I didn’t want to extend ground running of the engine longer than necessary, I had room to depart in front of the traffic so it was time to go!

The plane wanted to fly right away, I held it on the ground a bit longer (had plenty of runway) before taking to the sky. My plan was to climb out at a high airspeed (80kts) to keep good cooling airflow over the unbroken-in engine so I built up speed.

This brings me to my first (and only) scare of the flight. When I went to retract the flaps (coincidentally about the same time I had no usable runway remaining), my left arm apparently bumped then throttle back to almost idle.

I didn’t NEED to retract the flaps here, but the plane was flying and under control and my mind was already going to the next thing to do. There’s probably no harm in bringing up the flaps here (it’s only 10 degrees) and the plane was flying/climbing fine with or without them. There was no need to rush.

Here is ground footage of the initial takeoff. At 15 seconds you can hear the engine rpm drop.

I didn’t hesitate to push the throttle back up and immediately knew what had happened, so it didn’t bother me the rest of the flight, other than to be mindful of my arm movement. If there’s anything else that bothers me when re-watching the cockpit video it’s when I take my hand off the control stick momentarily to apply friction lock to the throttle. I really shouldn’t take my hands off the controls like that, especially that low to the ground, that’s what my other hand is for.

I learned pretty quickly (and it’s apparent in that moment I took my hand off the stick) that my plane had a tendency to roll left. It wasn’t anything that affected controllability but it did require constant light right-stick pressure to keep the plane level. This is something I will investigate and hopefully correct when I trim out the flaps in the future.

Pitch trim seemed dialed in, pitch forces were very light and I never felt a need to adjust pitch trim during this flight. Will probably be different when I start doing longer flights and want to trim the plane for hands-free flight.

Engine temperatures were pretty good, I peaked Cyl #3 CHT at 420 degrees at 35 inches MAP at 80 kts just prior to leveling off, pulled the power back to 30-ish inches and just cruised around 100 kts. After that I didn’t see temps above 400. I’ll do more accurate power/airspeed checks in future flight testing.

I did 4 circuits above the field over about 15 minutes (my plan was to fly for about 30 minutes) and on the 4th circuit I started to smell a lubricant burning smell in the cockpit. It wasn’t strong but it was there, and smelled just like the first engine start. I wasn’t terribly alarmed by it since there was plenty of fresh lube that never burned off during ground runs, but it was enough that I decided it was time to bring the plane down and complete the flight safely.

So, on downwind I gained some extra altitude, did some brief slow flight practice and worked the flaps for the first time. Everything seemed solid and stable.

Final approach was stable, descent rate was predictable, full flaps added nicely to the descent rate and required some power to maintain the glide path I was on.

Now for the landing. I landed fast, wasn’t paying a whole lot of attention to airspeed, was focusing more on the runway center-line with a plan to just carry speed and hold it off until it touched down. The touchdown itself was smooth enough and would have made for a nice wheel landing if that was my plan, but I wanted to do 3-point landings until I was more comfortable in a tail-wheel. Turns out I was carrying too much airspeed, 50KTS upon analyzing my video (stall speed should be closer to 35 KTS), and the plane wasn’t done flying! So, I bounced several times while continuing to focus on centerline.

I made the following video to demonstrate my pitch attitude at touchdown. Basically, this video compares the sight picture between a 3-point pitch attitude and the pitch I had when I touched down. Reference the horizon in relation to the front of the glareshield.

Obviously the pitch attitude shown in that video is from the camera and will differ from pilot to pilot. The main point is, if you can lock in the sight picture of a tailwheel Sonex/Waiex while on the ground, it’s the same picture you’re looking for when doing a 3-point landing and the view over the glareshield relative to the horizon is your best reference.

The landing gear handled the bouncing very well, I could feel the main gear legs soaking up the movement and lateral control didn’t seem to be affected at all.

Once back at the hangar, I pulled off the cowl and noticed a decent amount of oil seepage around the oil pressure sensor tap on the top of the crankcase. Oil level didn’t seem to be affected so it wasn’t a large quantity, but it’s definitely something I’ll need to address going forward. This oil was likely the cause of the smell I encountered in flight.

All in all, the flight was a great success and I’m very much looking forward to the next one!