Test Flight 1: First Flight!

 

Test Flight: 1
Date: Sunday January 10th
Description: First flight of the aircraft
Objectives: Extensive preflight and run-up of the aircraft, high speed taxi / aborted takeoff, normal take off, initial systems checkout while in the pattern, depart the pattern for engine break in, return to base, normal landing.

Airplane Condition: 40 gallons of fuel, 9.5qts of oil as read on the dip stick, 50lbs of ballast in the baggage compartment, single pilot (150lbs)

Test Flight Track Log:

Test Flight Report:

 

 

DAR Inspection

After a lot of back and forth with the FAA/FSDO(s) (months) I was able to finally get an appointment to get N5412K inspected. Yes, it was a lot of paperwork, no doubt about that, but the process was more or less straight forward on my side of it. I think all of the DARs are struggling with the new AWC application system, but that is a different story.  I felt fairly well prepared and didn't run into anything that I completely missed. The short of it, N5412K now has an airworthiness certificate. 

The one thing to really watch for in this process is the actual text in the Phase II kinds of operation. We had to go back and forth a couple of times with the DAR (the new AWC process) in order to ensure that all of the language was correct in order to get VFR, Night VFR, and Instruments defined in Phase 2 Kinds of Operation. Thanks to the RV10 community for helping me with the exact language to look for.

The process itself was more or less how all of the other blog posts read. Once I was able to find someone that was able to come out, we started the conversation about 30 days prior to the actual inspection. The DAR sent me a checklist of things that he was going to go through and I reciprocated with sending this blog URL with the caveat of "this blog is not actually my build log, I have a real build log." 

The process itself was fairly quick. It was more or less a very comprehensive pre-flight (with the inspection covers off) with in-depth inspection into some key areas that I am assuming that either are personal importance to the DAR or pushed down from the FAA. I had two tables with my build logs, the paperwork, the photos, the invoices, etc. We didn't really dig much into each individual entry, but when I scrolled through my photos and electronic build logs the DAR was satisfied that I met those requirements probably purely on the size of the folders. The plane itself had its main root fairings, inspection covers, cowl, baggage bulkhead panel off. For the items of the plane that where not immediately visible I did have photos of every mechanical connection for the things that I did not have access to. For instance I did not have any of the tunnel open or the seats out, but I had photos of every linkage, fuel system fitting, brake system fitting, and electrical connector for anything that was not immediately visible. As a backup I did have an endoscope camera ready to go just incase there was something we wanted to see that I did not have a photo for.

When the DAR sent over the checklist, I did ask a couple of questions and had photos in those questions to make sure things like my ELT antenna placement were going to be acceptable to him. The other common things that everyone else has said/argued I made sure were a non-issue. i.e. Control stick contact with anything, the availability of a Whiskey Compass, etc. The only unexpected thing that happened was the night before the inspection the FSDO asked for the Kit Built checklist. The DAR felt bad about this because everyone knows the RV10 is already on the approved kit list, but we made the decision that fighting it was not worth it, it was easy enough to complete and submit rather than argue.

Final Rigging

I performed an initial rigging a couple of months ago when I had to bend the control sticks into a tighter radius in order to clear the panel, but I was always intending to run that one more time right before I buttoned everything up and conducted the final "condition inspection". A post over in the forums led me to the actual location of the flight control limits. The limits are in the "techniques" manual rather than the build manual! 

The actual limits that need to be verified:

I ended up re-checking with the gauge that the ailerons were neutral at the bell crank and then moved the right wing control rod a turn and a half. 

Left Flap (0 degree)

Left Flap (Reflex position)

Right Flap (0 degree)

Right Flap (Reflex Position)

Left Aileron in trail

Left Aileron Up

Left Aileron Down

Right Aileron in trail

Right Aileron Up

Right Aileron Down

Elevator (left side) in trail

Elevator (left side) Down

Elevator (left side) Up

Elevator (right side) in trail

Elevator (right side) Down

Elevator (right side) Up

Pitch Trim (left side) Tab in trail

Pitch Trim (left side) Tab Up

<need to re-take the photo>

Pitch Trim (left side) Tab Down

Pitch Trim (right side) in trail

Pitch Trim (right side) Tab Up

Pitch Trim (right side) Tab Down

Weight and Balance

It is getting real now! With everything on the plane (at least first flight wise) it was time for the weight and balance. I am going to keep some of the interior out of the plane until Phase I is done. So the pretty side panels, carpet, and anything that covers up quick access to things like the wiring I am going to keep off. That said I will have to do another weight and balance when Phase I is complete.

Thankfully EAA 186 has a set of scales. Not only do they have a set of scales, but they have the complete setup that was plug and play to include the ramps to get onto the scales. While I did this by myself, it would have been handy to have a second set of hands to get the plane up onto the scales. While an inch and a half incline does not seem like a lot (especially over that ramp distance) I had to take a pretty good running start to get up onto the scales, and then stop quick enough in order to not blow past them. Quick reminder to zero the scales otherwise you will have to struggle getting the plane onto the scales twice...

With the plane on the scales, the next step was to put the plane into flight level. This line can get picked up at the door sills. Thanks to Jim at the chapter for mentioning to me prior to the start of this that letting the air out of the tires is the preferred approach to get the plane level. That worked well and was way easier than what I had planned in my head for incrementally adding shims under the main tires.

With the plane centered on the scales and centered, it was time to take some measurements. I started my marking out some layout lines and taking the measurements. The datum point in the exemplar W&B from Vans is 99.44 inches forward the wing leading edge. I marked that out and then took the measurements back from the Datum back to the nose wheel and the left and right main wheels.

That was pretty straight forward. With all of the layout done it was time for the big (moment). Taking the obligatory new baby weight photo! N5412K weighed in at 1650 lbs and was about as close as I could imagine it being from left and right balance. This puts me along side everyone else where I will probably contemplate flying with some ballast in the baggage area while flying by myself. That said, without ballast and single pilot N5412K is still within limits, so awesome!

Flight Test CG

 

Control Stick Bending

Something I have been putting off for far too long... When I put my panel in I ended up putting some switches and breakers into the standard location that the Aerosport panel has designed. That looks really nice, but after finally having everything rigged, the control stick would contact the switches prior to the stops in the control surfaces making contact. The internet is very helpful as everyone else that has installed the panel has also had a similar issue. (although it sounds like a lot of people just fly like that)

A lot of the solutions involved heating, bending, cutting, welding. So with all of that, I decided to wait in the process to when I had things close to final rig to ensure I knew exactly how much additional clearance I needed. I also ordered two new control sticks as I was assuming it was going to take a couple of different tries in order to get it where I wanted.  

I started with taking my existing control sticks out. I was about to cut them to weld some DOM tube extension but before I went down that path I figured I would just bend them a little to see how things looked. You do not want to bring the stick much more aft as it is already in your lap on full nose up. Also, you don't want to make a bend too low in the stick because (with my short legs) the stick will contact the seat cushion. 

With that, I grabbed a pipe bender from the place I most hate (harbor freight) and with the 1/2" mandrel bent the control stick 5 pumps at a time as high as I could. On the first 5 pumps I could see that it was having a significant impact. By the time I got to 10, the control stick with my custom grips was no longer contacting the switches by itself, but with my hand on the stick I could see myself accidentally flipping all of the switches off on a controls pre-flight check. With 15 pumps on the press you can see how much movement I got (and where I got it). 

At this point I was still thinking I was going to use the control stick as a template and move on to bending the new sticks, but I went ahead and installed them into the plane and everything fit very nicely. I am 5'7" and with the seat all the way forward in the forward most notch of seat adjustment (not where I fly, but the worst case for clearance) the stick came back full nose up and fit very nicely in my lap. I definitely hit the elevator stops before my body. (but I am also 150lbs). With both of the originals bent identically I called it a day as I was not sure I was going to be able to replicate that. Also, the original sticks were match drilled for the control stick horns, and I figured it would be difficult to re-drill the new sticks without enlarging that holes in that part.

Done.

The non-build things

Up until 2020 I was pretty good about staying current (not just legally current but comfortable current). When COVID hit airplane rentals became a little problematic. As things started opening back up I found myself needing a new medical, a flight review, and I needed to re-gain currency. On top of that I had been flying a 172 for the last 5 years so it was time to change that.

In June I started everything back up. I renewed my medical (last 5 year one for me), formally transitioned into the Cirrus, got back my currency, and started IFR training. I am enjoying the 300hp low wing and so is the family! 

We will miss the A/C when we transition over into the RV-10, but it has been a great experience.

 

 

Fuel Flow Test

 

Prior to the first start I had already cleaned, purged and tested the various aspects of the fuel system from the tanks through the filter and electric fuel pump, up to the fuel divider. I still wanted to run a full fuel flow test though. In fact when I emailed the DAR (not that I was not planning on already doing it) he had mentioned that he would want to see a fuel flow test. 

FAA AC 90-89B has some decent information on fuel flow testing. The RV-10 tanks are a pretty known design as is the engine combination, fuel line routing, boost pump, and filter setup. So really the test here is to make sure that the electric boost pump is wired and working correctly, that the flow through the lines is not restricted, that the lines themselves are free of debris, and that we can get the required flow rate out of our boost pump. Ideally I would have tested the "usable fuel" here as well, but Mackenzie was about done with the fuel test by the time we got through all of the essentials.

We started with the the plane in level flight attitude, and checking the various functions of the fuel selector and then ran the fuel flow test both on the left and the right tank. I purchased a nice fuel funnel from Aircraft Spruce that had both a water separator as well as a filter, so I ended up re-using the fuel for this test. From there we put the plane in the nose up pitch as far as we could (basically until the rear tie down was just off of the ground). 

Tests one and two we ran for 60 seconds for each tank. I will be honest, I did not get overly exact about measuring after we passed 4 qts in under well under 60 seconds. Regardless, the first test was over +67 gallons per hour (with the fuel being taken from the line at the input of the fuel servo). The second test was about +68 gallons per hour. I would say that the flow was probably a little more than that calculation, but my container was only 5 qts and I didn't want to make a mess. I opted not to go the other way around and have Mackenzie stop the timer at the 4 qt marker because I was in fear of the boost pump not coming off in time and there is A LOT of flow on that pump!

In looking through my engine documentation, I didn't see a fuel flow sensor on the max RPM test that was run so I am going to generalize a bit on max fuel flow for 2700 RPM. If we are running at mixture for peak power, the brake specific fuel consumption (BSFC) should be on the order of 0.5 pound/hp per hour, if the engine compression ratio is ~8.7:1. Let's round that up to 0.60 pounds/hour of fuel per each horsepower (even though our 9.0 compression ration should actually keep that number closer to 0.5).  Avgas weighs about 6 pounds/gallon, so we would expect about 10 hp for every one gph of fuel flow.  Take our Thunderbolt IO-540 engine rated at 295hp, we would get 29.5 gallons per hour (loosely). 

The rule of thumb here is that in our low wing electric boost pump enabled system we need about 125% of our max flow to be pushing through our line, so 36.9gph. I realize that I did not bring the line up to the spider, but our 68 gph is more than enough to meet our safety factor.