N3XH Phase 1 Flight Testing

[rodsmith]

Several builders have done a great job documenting their builds. What I have not seen is much detail about initial test flying, I plan to document my flights as I go through the task based testing as outlined in the new EAA gold colored flight test manual and test card book. My DAR gave me the option of task based or 40hrs. My test area is a 50NM radius from my home at Crawford airport (99V). He also asked for a list of airports I wanted to land at during phase 1 testing. I drew a 50NM radius circle on the chart and listed every public airport within it except Aspen and Telluride which have landing fees. They are documented in the restrictions on my AC. Crawford's elevation is 6470 with a 5000', 40' wide paved East-West runway (7-25). The runway has a 2% grade, sloping down from the East end. There is an alfalfa field on the south side of the runway smooth enough to land on, about 2000' usable. My first three flights I took off on pavement and landed uphill on grass. Christmas day it snowed enough that I won't be using that again until it melts off. The major hazard on our airport is deer. We have a local herd of about 30 mule deer, not uncommon to see some on the runway, especially during the winter. One of the reasons we recently made the airport day use only. I invite others to join in with their experiences, comments etc.

[Utah-Jay]

Nice post Rod.

I met with my DAR yesterday as he was on the airport and he looked at all my paperwork prior to me submitting it online. All was good! He has previously looked at my plane twice during the build. I asked for and received 100NM radius for phase 1 once I get my airworthiness certificate. I asked for 100 as it allows me to head to some lower terrain for engine break-in purposes, my home airport is at 5637’. Planning on the inspection in the next 10 days or so.

I too am doing the EAA task based phase 1. My buddy did it on their Kitfox and with someone on the ground on a radio relaying info it can be done in under 12 hours

[svyolo]

The DAR I used gave me 75 nm, and I didn't even ask.

[jaredyates]

Great idea Rod, this process has changed in the past few years and we can always use more ideas and data. I applaud you for taking the testing phase seriously, it will make for an optimal relationship with the plane. You'll know what it can do and how to make it do it. One option we have to make the thread easier to find is to put it into the Flight Testing channel, but that is entirely optional.

[rodsmith]

Card 1 - First Flight: Card 1 says to make this flight without flaps. I elected to take off with 2 notches and land with 3 notches. That is how I took off and landed while getting checked out in Virgil Irwin's beautiful Model 5. The other reason for flaps was I wanted to limit the ground speed during landing initially, which is quite a bit higher due to the elevation. I listed the primary goal of the flight as starting to break in the cylinders. Flying at full power is not conducive to completing most of the test cards, so the majority of testing will have to wait on the rings seating. The plane took off and climbed so fast I was definitely struggling to keep up. My plan was to climb to 8000' and circle the airport within gliding distance. Half way around the pattern I glanced at the altimeter tape and was at 8300' with 1700fpm climb rate. The only squawk on the first flight was way too much angle on the rudder tab. Keeping the ball centered, my left leg quickly went numb leading me to land after 20 minutes of circling instead of my planned 30 minutes. I don't know that there are words to properly express the feelings after successfully completing the first flight in a plane you built. Definitely a feeling of relief, mixed with joy, and awe that the plane you built flew like you hoped it would. Flying with Virgil gave me an idea of what the take off and climb performance would be. I can't thank Virgil enough for the time in his plane, the Five flies very much like the Four. I would not have made the first flight without some time with Virgil or Jared. My initial plan had been to train with Jared, the only reason I didn't was the sum of travel costs to North Carolina and feeling the financial strain of many unplanned expenditures during the last year of construction. Test Card 1 signed off!

[rodsmith]

Great idea Rod, this process has changed in the past few years and we can always use more ideas and data. I applaud you for taking the testing phase seriously, it will make for an optimal relationship with the plane. You'll know what it can do and how to make it do it. One option we have to make the thread easier to find is to put it into the Flight Testing channel, but that is entirely optional.

Great idea Jared, lets move this thread there, I don't know how to.

[rodsmith]

Nice post Rod.

I met with my DAR yesterday as he was on the airport and he looked at all my paperwork prior to me submitting it online. All was good! He has previously looked at my plane twice during the build. I asked for and received 100NM radius for phase 1 once I get my airworthiness certificate. I asked for 100 as it allows me to head to some lower terrain for engine break-in purposes, my home airport is at 5637’. Planning on the inspection in the next 10 days or so.

I too am doing the EAA task based phase 1. My buddy did it on their Kitfox and with someone on the ground on a radio relaying info it can be done in under 12 hours

Great idea, I had thought about asking for an expansion to include Moab, 4580' elevation. If I had gotten started earlier in the fall, my plan was to drive my travel trailer to Moab, park it on BLM land adjacent to the airport and do my engine break in there. I would have flown to Moab, via Grand Junction and followed I-70 there, instead of direct which is over some very rough country with few reasonable emergency landing possibilities. The G3X system logs 81 parameters. No need for a notepad while testing, allows more time to watch for traffic!

[svyolo]

I flew 2.4 hours today, so far 16.1 total. The weather here in the PNW sucks, but has been good enough to fly that in 3 weeks. I am good with the 40 hours, I am daylight,/wx limited so if I can get airborne, I try to get at least an hour. Engine runs good. Now getting the cylinders to peak EGT at same time so I can run LOP in the future. So far no issues with the engine, electrics, or fuel. My induction might be currently a bit below average. I can only maintain 24" MP up to 5000'. I have a fix for it, hopefully, but too cold to do FG work, it will have to wait until sprint. I did make the mold.

I flew 25 nm to the south to a different airport today and did some circuits. I think that is my first VFR cross country since 1982. LOL

[Nev]

Interested in how you fix that.

[rodsmith]

Your are doing great John! My intent was to fly every day after first flight, with all flights being an hour minimum. For various reasons that hasn't worked out.

[Nev]

Good idea for this thread Rod.

I found the 40 hour test phase to be far too long - 20 hours would have been plenty given that we're not testing a first of type, and most of our engines are closely derived from previously certified Lycomings or similar. Essentially what we're doing is testing that our systems and controls are functioning as they should, and fine tuning them so they do.

My initial few flights centered around ensuring there was no catastrophic issues. They were flown very close to the airfield and the first couple were kept within gliding distance. I was also running the engine in, so this initial few hours were at power settings too high for much else and limited to things like logging CHT's during climb to altitude. After about 2 hours the CHT's had all decreased, and I ventured further afield and continued the test program, using the NZ Sport Aircraft Association (SAA) and the EAA test cards. Both had their own strengths. All of the test flying had been completed by 20 hours and the remainder was essentially me learning to fly the BH and getting used to tailwheel handling.

Good idea to do the initial takeoff and landing with flaps. For manual flaps I can't see any benefit to going flapless, particularly in an tailwheel aircraft and particularly on a sealed runway. All of my test flying was conducted from grass runways, however I had the luxury of choice.

One interesting test was the flight to VNE. This was completed once all the fairings had been installed as I initially had a number of them removed for ease of access to make control adjustments.

The one small issue that took the longest time to resolve was the heavy left wing. Even when I thought I had it solved, I became aware of a small and stubborn "steady heading sideslip". All sorted in the end.

[svyolo]

Interested in how you fix that.

Fix which one? The engine leaning or low MP? EFI engine leaning is done "Gammi" style, but electronically. I can add or subtract fuel to each cylinder to get them to peak closer together. The MP issue is a design problem (mine). I have a 3" opening in the right intake on the bottom (many RV's use a filter in the left intake). It feeds a Vans' FAB via Skeet tube. I will make a fiberglass "scoop" to hopefully catch more ram air. I have seen stuff similar to that on some certified aircraft. But it is too cold for fiberglassing. I already made the mold.

Another hour of flying today. The weather was closing in or I would have flown longer. Heavy wing almost completely fixed, and getting close on the EGT peaking at the same time.

Each flight I make a few adjustments to the EFI. I can now start in the cold without ever changing the mixture. OIl consumption seems very low. 17 TT so far.

[Nev]

Well I was thinking of the MP issue, but actually both problems now that you mention it. Tell us more about the EFI system. Do you mean to say that you can effectively tune the nozzles.....without touching the nozzles, as in electronically ? That would be a real step forward. Making great progress there John and i enjoy following your updates.

[svyolo]

I will resurrect an EFI thread for that in the next couple of days. Might be thread drift for this one.

[rodsmith]

Flights 2 and 3. About 1 hr each no test cards completed. Forgot to mention that for the first flights I am ballasted to be 1/4 to 1/3 back from the front CG limit. That is per the test card and Bob Barrows. Two 60# sand bags secured where the rear seats would be, gave me a CG of 13.5. I made a major adjustment to the rudder tab, from 20deg to about 5deg. Now just need light pressure on the left peddle while high power cruising to keep the ball centered. Spent a good amount of these flights practicing turns. Started with 30 deg bank, then 45, then 60. Coordination is good but I tend to add too much back pressure and actually start climbing. Still working on that. The pitch really is quite sensitive. I performed a fuel flow test by starting at 7000' and climbing at 25 deg and holding that attitude until 40K then pushing over to level. Repeated at 30 deg. This was on both tanks, boost pump off. The fuel pressure never wavered from 28.5psi. Will repeat with left and right tanks selected. I also calibrated the airspeed at 22 squared, 8000'. Flew all four cardinal directions. East and west true air speed matched ground speed at 133K North was 132 ground speed and South was 134K gs. So airspeed is right on at 133K. Have to wait on testing at lower speeds. My first three flights, the air mass was very still. Would have been a perfect time for determining V speeds, glide speed, climb angles etc. I also checked lateral stability, trimmed for level flight gave the stick a push, settled back to the same airspeed after 3 oscillations. Fun stuff.

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Before

[rodsmith]

Flight 4-New Years Day: 1.4 hrs. Took off with 0 flaps, believe I prefer that if not doing short field work. Still gets in the air really short. I believe my rings are starting to seat. I could lean much further. My first flight, fuel flow was nearly 20 gph (not calibrated). Yesterday I got it down to 15gph, with the cowl flaps fully closed the entire flight. I try to keep my CHTs mid to high 300s. Highest cylinder yesterday was #2 at 380. Oil use has been way less than I expected. I started with 10 quarts the first flight, saw no decrease until after the 3rd flight, added 3/4 quart, after the 4th flight still showing 10 1/2 quarts. Practiced 75 deg banked turns, got the back pressure correct. I found that I really like 45 deg banked turns. I can see through the skylight to watch for traffic throughout the turn. Getting much better at maintaining altitude in level flight. Was bold enough to fly away from the nest to an airport 9 air miles away. It is 500' lower so was circling at 7500'. First time I have seen 23" mp. So far I have not found that the plane has any bad habits, it does exactly what you ask of it. Bob Barrows is a genius!. I really love this airplane! I have been doing very thorough pre and post flight inspections. Before flight yesterday I found several spinner screws starting to loosen up. I have an aluminum trim strip over the aft edge of the skylight two screws were gone and some others were loose. Seems like a strange place for high vibration. The engine prop combo seems very smooth to me, but when I get a chance I will get a dynamic prop balance.



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[TrueAirSpeed]

Thanks for your write ups Rod. You mentioned #2 CHT being the warmest of the six. I've experienced that with my 0-540 and have heard others mention it also. While #1 runs the coolest, #2 can be the hottest. I attribute that to the descending blade of the prop cooling #1 and the ascending blade of the prop not cooling #2. Your or anyone else's thoughts. Terry

[rodsmith]

I am very frustrated as my last flight was on Friday the 3rd. The rings seem to be seating. On that flight I was able to lean past peak with CHTs peaking form 370 to 390, cowl flaps closed. Of course you don't want to be lean of peak while breaking in, so set the mixture 125 deg rich of peak which is best power. The engine was at 6.5hrs after the flight so I removed the cowling for an oil change. Was very pleased to find the oil screen totally clean. I didn't have a filter cutter so had our on field mechanic open it up for me. The only thing in the filter was some small shiny flakes which he said were chrome flakes off of the rings, very common during engine break in. With the oil drained I installed the Antispat.aero oil pan heater in the right hand sump drain. After my second flight I had noticed some carbonized splatter on the bottom of the cowl below the exhaust header to muffler joint. After following flights the splatter seemed to slow down and stop. With the cowl off I discovered that oil had been dripping down the inside of the cylinder 6 intake header onto the exhaust header. I searched all over for the source of the oil but never found anything. I thought it must be from one of the cylinder head oil drain line connections but everything was tight and dry. Due to some other obligations it was a week until I got the cowl back on. I planned to fly Saturday, forecast was for overcast conditions but I woke up to a snowstorm. Monday was clear, cold and calm. I taxied to the fuel pumps and did a run up after filling up. The lightspeed ignitions have been very consistent with a 40 rpm drop on one ignition. This time running on #2 ignition, which powers the bottom plugs, I had a rough running engine and 150rpm drop. Back in the hangar I removed the bottom plugs and found nothing that looked like a problem. Now I am still trouble shooting #2 ignition and so far haven't found the problem. Trying to think what might have happened with the cowling off to cause the problem. Have missed two beautiful flying days so far and the next three are supposed to be the same.

[svyolo]

My engines 1st 5 hours I had bottom plus foul several times. Auton plugs. i started doingv a Mag chech after landing as wellI. Hasnt happen since. I pulled the offending plugs and found small bits shorting out the plugs. Again, hasn't happened since 5 hours. 35 hours now.

[gregc]

An option similar to svyolo's suggestion is to run the engine at a high idle (1200 or so) for 30 seconds before shutting it down.

[kestrel]

Do you have an engine monitor that lets you see EGT and CHT for each cylinder? That should be able to tell you which cylinder has the problem.

[rodsmith]

Excellent point, I should have thought of that.