The Journey Begins

“When everything seems to be going against you, remember that the airplane takes off against the wind, not with it.” -Henry Ford

 

Fuel Pressure, Rigging & A/P Servo

It has been a busy two weeks but unfortunately with minimal flying. Let talk about the biggest concern that I posted about in the last update. Varying fuel pressure. I was suspecting some sort of vapor lock/early vaporization and the guys at Lockwood suspected that same thing. They recommended I get at least a 50/50 mix of 100LL (aviation fuel) in the tanks and try that. I drained some fuel out of one of the tanks and topped them off with 100LL making the mixture 2/3’s 100LL. I will share that in my conversations with Lockwood I discovered that the fuel pumps on the 914 are the same as the ones on the 912 which means the Service Bulletin was for them as well. I guess I misunderstood that SB. In many ways that make me feel better about the situation concerning my pumps failing as they were from the time when that was occurring. Mystery solved ?? The other thing they shared was that, like everything regarding supply chains right now, they said I really should not trust that I am always getting summer blend gasoline right now. Interesting thought, If did get a batch of winter blend that could explain a lot. I cannot prove anything but it is an interesting thought.

Before I took it back up I received the new A/P servo from Garmin so installed it. They were good about it and after checking the serial # they took care of it at no charge. Getting the old one out was easy but getting the new one back in was more difficult. I remember it was challenging the first time. Regardless, I got it changed over.

The last thing I did was adjust the rigging of the right aileron and flap. I have had a slightly heavy left wing and when I really took a close look at the rigging I had done when everything was installed I found the right aileron was a several millimeters low when the left aileron was held in perfect position. I adjusted the right aileron up and when I did that it highlighted that the right flap was also low by a couple mm’s. I adjusted that as well I did not do anything to the left side.

Last night I took it up and stayed in the pattern for some practice but also to stay close to the airport and see what was going on with the fuel pressure with the new mix of fuel. The fuel pressure moved some but only between 3.7 and 3.9 psi. Okay that was better. It also seemed like the heavy wing was somewhat better but I needed to get it up to cruise speed to really verify.

This morning I was back at the airport and went for an hour long flight watching everything closely. I got as high as 4,000 feet. Like last night the fuel pressure was fluctuating between 3.7 and 3.9 psi. The changes were not as drastic nor as quick and there was plenty of time when it sat at 3.8psi and did not move for an extended period of time. I do not know if this is normal or if it should be rock steady so sent another email this afternoon to Lockwood to understand what “normal ” looks like regarding fuel pressure on a 914. I will share what they tell me.

Regarding the heavy wing, I got it up to cruise speed (105kts +) and there is not doubt the situation is better but not completely resolved. I may see about another very small adjustment. I saw in Jim Pavlick’s recent post (Congrats to Jim on his first flight !!!) that the guys at Sling suggested a trim tab on the right aileron to address the same issue. That will remain an option.

The other thing I am looking at is the operating temps (oil & CHT). No they are not high but actually a little low. In the pic below you can see oil is running at 167 degree. It was higher after climb out but then fell back. In the pic you can see I am running with the engine pulled back a little (manifold pressure). I do not like to run full power in cruise configuration (5,000rpm). I have been told it creates a lot of stress on he crank. I think next flight I will try the “hold” functionality on the prop where we you can set the rpm you want and it will then hold that rpm. I am thinking 5,200 rpm for full power cruise.

The other thing this pic highlights is the gallons per hour (7.1). For a MP of 30.2 I am thinking that GPH reading might be a little high. I will carefully start measuring how much I use and compare it to what the G3X is telling me. That will tell me if I need to adjust my K factor. It is set at 35,000 right now. It is close but want to get it REALLY close.

Flight observations with full tanks: I could barely tell a difference. Maybe a little more up on the trim tab at take off but that was it.

Slow Going/More Squawks

Getting time to to fly has been challenging which I find frustrating and what is even more frustrating is issues keep coming up. So far I only have 12 hours on the N77RL and I have a few more things to sort out that popped up in the last 10 days. Before I get into that I will start out on a positive note. My local EAA chapter (Ch 106) which is at the same airport as I am based (LWM) had a fly-in last weekend in which about 30 planes made an appearance which for this chapter is a really good showing. I taxied around the corner and added N77RL to the line. It got quiet a bit of interest as it was the only Sling and most had not seen one in person.

Okay so the first thing that popped us is something that I have seen mentioned on other blogs. I got a message on the G3x that one of my A/P servos had a fault.

I took off the covering plates that are under the pilot seat to have a look and make suer there was nothing going on with the connector and saw the red light on the servo itself. I have not even configured the AP yet.

I reached out to Steve at Midwest Panels and he verified what I knew, that there was a bad batch of servos a couple years ago. He was reaching out to Garmin to see what can be done. We shall see……

The other thing that occurred was that Saturday morning I took a flight and took it up to about 5300 feet and was watching the engine monitor and the fuel pressure was all over the place. After my recent issue with the fuel pumps needless to say I was quiet concerned. The fuel pressure was quickly changing from as low as 2.5 to as high as 4.5 psi in a matter of seconds. Up until now when ever I checked it it was rock steady at 3.6 psi. This was while it was operating on the main fuel pump. I should have turned on the AUX pump if for no other reason to see if it changed anything but my brain was telling me to save it in case the main was failing. If you remember I had both pumps fail on me while it was on the ground. I turned back to my home airport and looked for airports to fly over but was not in a good place with no airports close. Needless to say I very intently played the game of “where would I put down if things went quiet” just like my instructors taught my all those years ago. It took close to 30 minutes to get back to the LWM. I noticed as I got closer (and therefore lower) the situation was stabilizing. By the time I got back on the ground it was back to a pretty constant 3.6 psi. I did a full power run-up back at my hangar and it remained stable. Was I experiencing the fuel vaporizing early at the higher altitude? I have read about that but I was under the impression that was mostly an issue with the winter blend of gasoline. I am running 93 octane Mo-gas (has ethanol). I took a video of the panel and am going to send it to the guys at Lockwood aviation for there thoughts. Unfortunately I cannot load videos to my blog as I would need to buy hte an upgraded package. Needless to say I did not fly today as I want to hear from them first. Maybe blend what gas i have with some 100LL ??

Even though I was not going to fly until I know more I did go to the hangar this morning and looked over my aileron/flap rigging as I have a slightly heavy left wing. I was thinking it was because it is just me in the plane but thought I should have a look anyway. I did notice the starboard wing flap was slightly lower than the port flap (3-4 mm) when compared to the wing root as well as the starboard aileron was slightly low by a couple mm’s when compared to the wing tip as well. I adjusted them both. We shall see if just a few mm’s will have an actual effect.

I will say that both the A/P servo issue and especially the fuel pressure issue have resulted in me not enjoying this anymore. I just want to fly and am getting tired of working on issues. I had hoped by now to be in a place where I trusted the plane more than I currently do but unfortunately I still have a long ways to go…..

Addressing Squawks in the First Ten Hours

I had put about eight flying hours on the plane, including my first flight away from the airport when a couple items became apparent that needed addressing. For those with the 914 you may want to read this to the end as I found some really interesting information about this engine from Lockwood Aviation. First item I wanted to address was to make the pilot side door latch with more authority. I took my Dremel and put a slight indentation in the hooks in order for the latch post to engage with more authority. Did not take much grinding at all and it now really has a ‘thunk” when latching it closed. I also got the rest of the carpet installed on the pilot side.. I will leave the co-pilot side out as I will not install the center console panel on that side until after 25 hours.

Even with only eight hours the amount of bugs was significant. Thank you Sabrina for helping scrub !!

Next I noticed the alternator belt had loosened up some. I would think it might be normal for it to stretch a little bit in the first several hours. Tightened that up.

It was not until I had about five hours of flying in that I realized that I was not getting audio alerts from the G3x. I verified they were not working as you have the ability to test the various alerts in Configuration mode. I contacted Midwest Panel Builders and Steve helped me identify that a pin on the GMA 245R was in the incorrect location. In the pic below I circled the pin in question and where it needed to move to. Moved it and all is now working properly.

So the last item I needed to deal with was the engine. I had been noticing the rpm drop when checking the left magneto was 400 rpm which is more than the POH allows for. Also the engine was running pretty rough while it was running on that one magneto. I was also experiencing a backfire when shutting down. This was not a small backfire either, more like a 30-06. People would dive for cover. Pretty embarrassing. I reached out to Lockwood Aviation and they shared that the 400 rpm drop is nothing to worry about and that Rotax had put out guidance to that effect. Apparently the two magnetos have slightly different timing. Interesting. They did say that the rough running was something to pay attention to. You would think that the roughness experienced during the magneto check would be attributed to the ignition but not so. At that rpm (roughly 3500) it was more likely to be carburation. Phil Lockwood shared that I should pull the carburetor bowls off and first weigh the floats to see if there is an issue there. FYI I had already verified that my floats were the correct ones (had the “R” on them). Together they should weigh six grams He also shared to weigh them right away in order to get a true reading since gasoline evaporates so quickly. Three of the four weigh 3 grams each and the fourth weigh 4 grams. I will ask if that one is an issue. The other thing he stressed is you can not over tighten the bolt on the bottom of the bowl. If you do you can warp the bottom of the bowl which will in turn bend the posts that the floats ride on outward which could result in the floats touching the sides of the bowl. This would result in more fuel flowing to the carb than is needed which causes the cylinders associated with that carb to run rich. I looked at each of the bowls closely and there was one post on the right side carb bowl that seemed to be slightly bent towards the outside of the bowl so I slightly bent it back towards the middle. I saw no indication of it being over tightened but will share that getting a torque wrench on the bolt on the right side carb is nearly impossible with all the oil lines, turbo plenum and exhaust manifold. I think you would need a crows foot which I did not have. I practiced putting the torque wrench in a vice to see what it took to get to 5.5 Nm. I then approximated that with a wrench erring on the lighter side. I then put it back together, including safety wire. As I am sure all of you area aware you have to drop the drop trays to get the bowls off.

Seeing the above picture reminds me I need to put some heat shrink on that choke cable.

Anyway, I got it all back together this afternoon and started it, let it warm and performed a magneto check. Much better !!!!! The engine was smoother when running on the left magneto and the rpm drop was less that it was before. Sweet. And lastly, no backfire !! All I can think is the slight bending of the float guide/post made a difference. With these issues resolved it is time to fly….. Lets go !!

Center Console and Other Bits

4.0 Hours

I spent the whole day at the airport correcting some small squawks as well as starting to install the sides of the center console. The time absolutely flies when you are doing something that really interests you !! I thought putting in the three panels that make up one side of the center console was going to be relatively easy. As usual, not so much. In the below picture I highlighted the area of the upper panel that had to be trimmed as it would not slide up far enough for the holes in the panels to line up with the rivnuts. The issue was the lip of the dash that sits under the throttle quadrant plate. There was also an issue with the panel hitting the fittings on the fuel tank selector. Just started slowly trimming the panel until I created enough room for the panel to slide up enough to have the screw holes line up. And yes, I see the loose wire under the dash. I secured it after the pic was taken. The really hard part is getting way up under to install the screws at the front of the front panel. Brutal. Gonna bring my 5’2″ daughter when I do the other side !! I think I will wait to do the right side until after the 25 hour inspection (The factory calls for a thorough condition inspection after the first 25 hours).

I had noticed on a previous flight that the duct work that brings fresh air to the pilot side has fallen out of the vent. It does not surprise me as I had a rough time with that. In order to get it back into place I had to remove the G3x. Once in there I used a light layer of glue to keep it in place.

Back in place.

I have gone around the plane a couple times making sure no screws are loosening up. I did find the screw that holds the pilot door rear latch had loosened up some. I took it off and reinstalled it with some fresh Loctite 222. I will be paying attention to that going forward.

The other thing that I was able to correct was the flap situation. After deploying full flaps when I bumped it up it would move slightly up to the 30 degree position telling me that it would go past 30 degrees when going down (just by a few degrees). When doing touch and goes it was a pain. I went in and re-configured the 30 degree position to match the fully down position and that took care of the issue. Nice. Another thing I realized was I am not getting any of the audio alerts through the G3x. Time to research that.

I did manage to get up for 45 minutes of pattern work today. The winds were only blowing about 10-12 mph but what a rough ride it was. I had my hands full. I remember from the past that runway 23 at Lawrence was always bumpy on short final but my goodness. I did six T&G’s then called it. It felt like a VERY light plane today. The airport was pretty quite today so I guess others were aware of it as well. Tomorrow, assuming everything continues to operate as expected I will leave the pattern……

Back in The Air

I received two new fuel pumps from Lockwood Aviation and installed them along with the new wiring that I showed in the last update. The pumps worked properly and I verified no fuel leaks. I asked my test pilot to come back which he was able to do very quickly. I showed him the result of the pump autopsies and both he and I felt that the prolonged running backwards had to play a role in the pumps failures. Based on that he took N77RL back up. No issues. He came back and I jumped in the left seat and had a flashback to the last time we were both sitting the cockpit. This time the pumps operated as expected. We took her up, the first time I have flown in my plane, and it flew wonderfully, light and precise. We returned to the pattern for some touch and goes. I appreciated having him aboard as I was rusty, especially with a good crosswind. I had not flown in a year (last time was when I was in Torrance for my dual instruction). I got better each time and we called it a night. I really appreciated his participation as he was grounded yet full of encouragement.

Due to weather I could not get back into the plane for several days but was finally able to do it Saturday evening. I will fully admit to some anxiousness but I soloed the plane for the first time and all went well. I will share that I stayed in the pattern. I will do that for several hours until I start building some trust in the engine. I need the practice as well. Everything went well. Sunday night I was back at the airport for more pattern work. It was stunning night with almost calm winds which makes it easy to feel like a good pilot when you are able to execute several good landings in a row. Here are a couple observations I have on the flight characteristics of the Sling 4 versus the TSI. The biggest difference I see is that with the higher lift wing the Sling 4 can really float in ground effect. I have no issues with ballooning, just that it does not want to settle down too quickly. I agree that it is probably related to me carrying too much speed, on short final I hold 70. That may be fast but I have not done any slow flight work yet as I have not left the pattern. Once I get away from the airport and am able to perform slow flight exercises I may bring it down to 65 on short final (with full flaps) but at my airport there is plenty of runway so am not worried about a longer landing at this point. The controls are light in both roll and pitch. Making pattern turns are just finger tip controlled. The other big difference between the TSi and the 4 is power. I guess that is obvious. The biggest difference is that you really need to stand on the right rudder during climb out in the TSi while the 4 is much more balanced. Of course the four is not as fast but everything is a tradeoff.

I have left the center console sides off up to this point as I knew I would be pulling the fuel filters to see if everything is okay. At this point the plane has 5.0 flight hours and thought it appropriate to have a look at them.

Super clean. Nothing at all. I was expecting a good result as I had flushed the tanks before first flight but as Ronald Reagan said, “Trust but verify”. I am really happy with these filters as they have enough size that if something should get to them there is enough surface area for the fuel to continue to pass. I got them from Summit Racing and ordered the steel replacement filters as the units come with a paper filter. I may leave the center console sides off until the 25 hour inspection as it will reduce the amount of work I have to do.

So a couple of squawks that I need to address. Regarding the plane I need to revisit the flap settings for 30 degrees. The flap controls are on the stick and work perfectly. Bump the toggle down once and it goes to 10, bump it again and you get 20, again for 30. Perfect. However on the way up when you bump the switch the flaps only move slightly at first. It took a minute to realize they are coming up to the 30 degree setting, Coming up to 20, 10 and 0 work as expected. I need to go back and reconfigure the flaps. It is really only an issue when doing touch and goes as it is distracting. That is all I have for the plane. I want to update my checklist with a few more items specific to my plane and panel, like resetting the fuel used to zero before each flight. There will be more. As long as I don’t have any fuel pump issues at start up I will leave the patten and commence properly testing the plane.

Fuel Pump Autopsy & Replacement

5.0 hours

First I must apologize for calling the capacitor a diode in my last update. The capacitor is required by the Rotax installation manual, one for each of the fuel pumps. The new fuel pumps arrived very quickly from Lockwood Aviation. With those in hand I decided to perform an autopsy on the old pumps to see if I could determine anything. I used a Dremel to cut a slit in the aluminum casing of the pumps and them peeled it back.

Under it is a steel case that holds the magnets and motor. The pump itself sits on the left but fell away as the aluminum case holds it in place. There is a pic farther down.

To get inside I had to cut another slit in the steel case. Below is a pick of all of the parts of the pump assembly.

The first thing I wanted to check for was an obstruction of some sort so I pulled the pump itself apart. Below is the pump.

And here it is taken apart. There were no obstructions

I then looked over the motor in greater detail and found marks on the top of the motor where the brushes make contact.

That would leads me to think that there may have been a short or a voltage spike. I did not like the job I did installing the capacitors between the positive and negative wires as I had left the capacitors exposed and well as some of the capacitor leads. I cut the whole assembly off and started over. I like the revised approach much better as the capacitors have shrink wrap completely covering the leads as well as a larger piece of shrink wrap securing the capacitor to the wires.

I took the pump assembly and the new connector/capacitor assemblies to the airport this morning and installed them. The pumps ran smoothly and there were no leaks. I pulled the plane out and started it and let it run for 15 minutes then checked everything over. No leaks. I started and stopped each of the pumps numerous times watching fuel pressure while also watching the electrical system via the VP-X page looking for any anomaly. After I got home I thought I should have done a full power test as that is when the generator is really producing amps. I will do that this week. I got under the panel and looked for anything that looked amiss but that is kind of a stretch as access is difficult at best. I also took out the GDU460’s (the EFIS screens) and looked around as well (almost all of teh avionics sit on a shel behind the screens). I saw nothing out of whack.

I am of course still very concerned as I did not find the smoking gun…..

She’s Up….

On Monday May 23rd 2022 four years and two weeks after taking possession of S/N 133, N77RL got off the ground !! As I mentioned in my prior post I had hired a test pilot for the first flight. He arrived in the morning and he spent a couple hours pouring over the plane. He was really thorough and made a couple common sense recommendations regarding better securing some wires and even found one Adel clamp that was not completely tightened down. I really appreciated his thoroughness. In the end he said it was one of the cleanest amateur built planes he had seen which obviously made me happy but I did not get too excited over that as the proof would be in the flying. After that we ran the plane for a while and then he took it to the runway for a high speed taxi test followed by a crow hop (flew the length of the runway just a couple feet off the ground). After that it was time to fly. I will share that I was anxious as it hit me that how well I did my job would impact his safety. He flew above the traffic pattern and circled the airport for maybe 15 – 20 minutes then returned. He really liked the way the plane handled though did have some feedback about the elevator trim. I need to adjust it further to give it more “up” trim. He indicted it was not an issue flying just that on final he was all the way up. He also said he felt like he needed to add a little bit of left rudder while flying.

While he went to lunch I pulled the cowling off and went over everything to make sure nothing bad was occurring with the engine which it was not. When he got back I added some more fuel (for the first flight he wanted the tanks only a quarter full) and he recommended I put the wheel pants on as he felt you cannot tell how the plane will truly fly without it in final configuration. He took it up for a longer flight this time and returned saying the wheel pants eliminated the left rudder situation. There is no substitute for experience. With two flights completed he said “Let’s go !”. I added the rest of the fuel I had giving the plane a little less than half tanks and fired the plane up. This is when I was brought back to reality. Things were just going too smoothly. The engine fired but then I immediately saw a fuel pressure warning and there was zero fuel pressure even with both pumps on. We watched for a few seconds wondering if it was a gauge issue as the engine was running but it soon quit. The engine had been running on what was in the carb bowls. Both pumps were not working. No noise at all. We were both flabbergasted. We both sat there thinking the same thing ie. 10 minutes earlier and he would have still been in the air and ten minutes later we both would have been in the air. Once the shock wore off some we started trouble shooting. Each pump has a different power source. The main come through the VP-X and the Aux comes through a manual breaker. Each has it own ground so nothing common there. I verified that there was power to the connector that attached to the pumps. I needed to think and it was getting late so I walked away. The next day I returned and found that I could get the main to run if I tapped it with a screwdriver handle (kind of like hitting a worn out starter) but I could not get the Aux to work at all. I took the pumps off and tested them with a 12 volt battery adn a couple leads. I could get the main to run but the aux was completely dead. I have to wonder if the problem I had way back when I put them together where I had the polarity was reversed (the pumps were different than the manual) therefore the pumps were running backwards (would not suck fuel) might have damaged them in some way ? Or did I screw up the diode(?) install you put between the positive and negative pump wires. If that is reversed would it damage the pumps ?? Could it be something else ?? I think I am going to check with my Panel guys and get their take but regardless I ordered new fuel pumps today from Lockwood Aviation. Depending on what the panel guys say I may cut out the diodes I installed previously and redo them. This would mean that I would have new pumps, connectors and diodes installed. I think I am going to take apart the Aux pump as well to see what is in there.

What is Going On ?

At my visiting brother’s encouragement I am providing an update on what is going on with N77RL. While I have been doing some work it is mostly checking things over and prepping it for first flight (example: removing the wheel pants and finishing off some last minute carpet installations).

The bigger things I have been working on is first I needed to secure flight insurance. It was about as painful as I was expecting. I went through a local aviation broker and the result was only two carriers would provide me a quote. Most said the Sling 4 was not on their quote approved list yet. The feedback was there is not enough of a sample size flying yet which I find hard to believe as there are lots flying in South Africa and other parts of the world. I think I would be the biggest factor in not getting a quote being a low time pilot. They just did not say that. I did secure coverage but at a ridiculously high premium. The first number starts with a seven. Ugh. I am carrying full hull coverage (what I have into it) for the first year. I will re-evaluate next year. The vast majority of the cost is the hull insurance. The need to reduce the premium will be a driving factor in building as many hours as possible before next year’s renewal.

The second thing I have been working on is securing a test pilot for the first flight(s). I had to have a serious conversation with the fella in the mirror about how prepared I would be to handle an in-flight emergency. The answer, at least to me, was pretty obvious. I could see myself getting over saturated quickly. This fact was driven home by a friend who acted as the ground crew for a couple first flights performed by low flight time builders. He shared that you could feel the stress coming through the radio and one had a hard time getting the plane safely back on the ground even through it was flying fine. I am lucky to have a professional test pilot in the area who has agreed to do it. I also really like the fact that the plane will have yet another set of eyes looking it over. Hopefully it will occur next weekend as he is currently traveling.

Airworthiness Certification

3.0 Hours

Today was a big day as I had a DAR at the hangar this morning to perform the airworthiness inspection. Bottom line is that four days short of having the kit for four years I now have an Airworthiness Certificate for N77RL !!! I am very relieved to have this behind me. The DAR was thorough in reviewing the plane placing an emphasis on the engine, and rightly so. After looking it over while in the hangar I then pulled the plane out and ran it while he looked it over for leaks, etc. I did not get any pictures as I it was just him and I and I was pretty busy talking with him. During the process he also quizzed me regarding my knowledge of the plane in general. Bottom line is the FAA’s view is N77RL is now an airplane. I now have to finalize my insurance and make some decisions regarding first flight.

Transponder & Pitot System Certification

2.0 Hours

You may recall that the Avionics Shop that was working to certify my transponder and pitot system could not finish the job due to the end of the day being reached. The tech had found a couple leaks in the pitot system that had to be chased down. It took a little while to get them scheduled to come back but that occurred last week. During the first visit the leaks were fixed from the entry point to the fuselage to the avionics. That left the connection point from the wing to the fuselage and the connection point at the pitot tube. I had used two push connectors for bringing the two tubes (pitot & AOA) together underneath the pilot’s seat but the tech from the first visit did not like the way those particular connectors worked and thought they were leaking as well. Before the 2nd visit I removed them and used the simplest connection method possible which was to just push the smaller tube in the larger one. I warmed the larger tube up slightly with a heat gun then pushed. It was still a very tight fit but was able to get the below result.

Next I revisited the pitot tube connection points out in the wing. I heated up the tubing and slid the plastic tubing over the metal pitot tubes and zip tied them as well. I then waited for the techs to do the complete test. They arrived found no leaks at all !! If you recall I do not have the typical static ports on the fuselage (based on feedback from the factory). I terminated the static line behind the dash. The techs used a piece of plastic tubing to connect the test equipment to static system. They then left the tubing in place after the test including the fitting on the end to make it easy to connect for future tests. See below.

I received some good news yesterday afternoon from the gentlemen I am renting the hangar from. He indicated that I could keep using the hangar until at least mid summer which is great as I am still struggling to find a permanent situation. It buys me some more time.

I have been in contact with a DAR and will be submitting the Airworthiness Certification online application today or tomorrow.