Wednesday, October 26, 2016

The Eagle Flies!!!! The Long Awaited For First Flight

Monday morning was a monumental occasion at DOG Aviation. A little over four years after beginning assembly of the DOG Aviation RV-12 the time had finally come for the Eagle to leave the nest and take me along for the ride. To the best of my knowledge, the DOG Aviation RV-12 is the first RV-12 to fly that is constructed using flush rivets on all the exterior surfaces ... I only know of one other RV-12 in Florida that is being constructed with flush rivets and it has not flown yet.

With the help of ground crew members Mike T. and Bernie, the RV-12 was rolled out of the hangar and into the brisk 48 degree morning air.
Ground crew member Mike T. was an attendee for the maiden voyage event.
Ground crew member Bernie handed me his phone so I could receive good luck wishes from Mike K. the remaining ground crew member who, unfortunately, couldn’t be present.

After the well wishes were out of the way, got myself strapped in and began working through items on the pre-start checklist.

Inside the cockpit preparing the RV-12 for the maiden voyage.
Gee, this looks serious. Also of note: One can see Mike’s new small video camera clamped onto the right seat frame … more on that below.

The Rotax 912 engine was started easily enough but it did require leaving the choke on a little to keep the engine running smoothly. This was by far the coldest day that the engine was started so when the choke was pushed off (as I have been doing during the warmer days) the engine instantly cut out and required a restart. This time, a little choke was left on until the engine warmed up to the point that easing off on the choke didn't result in a loss of RPM. With the choke now off and the engine warming up slowly, the RV-12 was taxied around to the other side of the hangars and a call was made to controllers to obtain taxi clearance to the far side of the airport to get to the active runway.

A little back story about the camera that can be seen I the previous photo ... Mike  T. came by the hangar last week and said he had a surprise me. Mike unzipped a small bag revealing a small video camera that could be used to document the first flight …. Very cool! The camera could transmit to Mike’s smart phone so the video could be watched on the phone while the camera angles were being adjusted. Sweet setup! The “plan” was to turn on the video camera after a successful run-up was made prior to taking the runway. Well, unfortunately that didn’t happen … with all the adrenalin, excitement, and first flight concerns, plus interfacing with the air traffic controllers, I simply forgot to reach over and turn the camera on.

After the run-up and forgetting to turn on the video camera (sorry Mike), the RV-12 was rolled onto runway 1 at KCAK to begin its maiden voyage towards the broken clouds high overhead.  After lining up with the runway’s centerline, power was applied and the Rotax 912 engine quickly accelerated the RV-12 down the runway with seemingly no effort and easily pulled the RV-12 off the ground and towards the clouds, taking me along for the ride.
Bernie snapped this photo of the DOG Aviation RV-12 just after the crosswind turn.

Admittedly, I was taken a little by surprise at how fast the RV-12 seemingly leaped off the runway and began gaining altitude. I was expecting to be on the ground a little longer based on the RV-12 transition training taken in California. But then it occurred to me … that was with an instructor in the aircraft more than doubling my own weight and also in much hotter 95 degree air compared to the much denser 48 degree air currently at the airport. The takeaway for fellow RV-12 builders about to fly the bird for the first time …. everything will happen quicker than when you were in the RV-12 with an instructor receiving transition training. The RV-12 accelerates quicker, gets off the ground quicker and climbs quicker … it is impressive.
Return from the future: Below is a short video of the DOG Aviation RV-12's first test flight that Mike made with his cell phone.

I had no intentions of making the first flight long or even working on Van’s flight test cards. The sole goal for the first flight was to get the bird in the air and fly a loop or two around the airport and land for inspections. As it turns out, due to traffic, I was instructed to extend the downwind and wait for the tower to call my turn to base. This took me much farther from the field than I would have desired for the first flight…  but time wise, it probably almost worked out to making two tight loops around the runway, so when given the OK to make the turn to base, the decision was made to just land and taxi back to the hangar.

Unfortunately, there are no photos of the takeoff or landing which is unfortunate. (Mike did get a short video on his phone of me flying overhead which I’ll post when I receive it). Making an initial flight from a larger class C airport does not lend itself to on field photographic activities. One can’t just walk out to the edge of the runway with a camera in hand and snap away without dealing with airport security and a likely a very long conversation with TSA personnel.

The return to terra firma was nice and smooth along with being centered on the runway. Just the way you want the first test flight to terminate … uneventful. Although the time in the air was relatively short, I didn’t notice any control issues with the RV-12, but then again, I did not get it up to cruising speed either. Did notice right rudder was needed to prevent yaw, but knew that would be the case since the rudder has no trim tab yet. Notice the word yet … the DOG Aviation procurement department decided to order a sun shade and canopy cover through Van’s and along with the order, had Van’s include the trim tab for the RV-12. Unfortunately, the trim tab was not available when construction began on the rudder four years ago.
The "RV grin" … after a successful first test flight in the DOG Aviation RV-12. In a way, my late friend, fellow pilot and Oshkosh partner Marty Dippel was also able to partake in the first flight of the DOG Aviation RV-12 … in that, I was wearing Marty’s leather flight jacket.

After the above photo was taken, the RV-12 was rolled back into the hangar and the upper cowl was removed for inspection. My friend Bernie noticed a drip of an oily substance on the bottom cowl's aluminum heat shield under cylinder #1. I ran my hand under the valve cover gasket and got some dark oil on my fingers. The first thought was the valve cover gasket was leaking … but the darkness of the oil didn’t make sense. Upon further investigation with a mirror, the substance appeared to be coming from an exhaust stud that secures the flange for the exhaust pipe to the exhaust port on the cylinder. The oily substance is very dark, so there is no way its oil leaking from the engine. Our conclusions, it is likely a lubricant left over from the machining process or some type of anti-seize lubricant used during assembly. This assessment was made based upon further inspections of the other cylinders which revealed the same thing occurring but to a much lesser degree. Unfortunately, we cleaned it up before I thought of taking a photo for the blog.
Return from the future: This is a photo taken using a mirror that shows the area around the #1 cylinder exhaust flange stud that the dark oily substance mentioned above was coming from. This photo was taken after a little over an hour of flight time. Now there is just a little streak of the dark oil … which seems to confirm to me the oil that was dripping after the first flight was likely from the machining or assembly process. The tipoff for me is that the oil is dark and dirty looking ... if it were actually engine oil, the oil would be clean looking like the oil in the oil tank.

The only actual possible leak found during the inspection was a small smear of oil on the bottom of the fitting for the oil line coming from the oil cooler where it attaches to the right side of the engine. Not sure if this was an actual leak or a smear of oil from when the oil line was installed … but just to be on the safe side, the fitting was made a few degrees tighter with a crows foot wrench. So this will be a location I will need to be keeping my eyes on during the next few flights.

Return from the future: After tightening the oil line fitting mentioned above a tad more, there is no longer any signs of leakage.

Wednesday, October 19, 2016

Carburetor Balancing Completed With CarbMate

Getting impatient and wanting to move forward I was looking around for an alternative source for the vacuum gauges when I stumbled upon the CarbMate TS-111 in stock at a local racing store (Summit Racing) at a fair price. I have read where other Rotax 912 owners have used this unit to balance the carburetors with good results, so decided to get one on will call and made the drive to Summit and picked it up.
The CarbMate TS-111 carburetor syncing device. A single row of LED’s are used to show the user if the second carburetor has a higher or lower vacuum than the reference carburetor. When both carburetors are synchronized, the green “happy face” LED in the center lights up.

So today the RV-12 was rolled outside and fired up and the CarbMate TS-111 was used to balance the carburetors. Because I decided to use the vacuum ports on the intake manifolds, it was necessary to block off the crossover tube. This is done by flattening the rubber hose from the manifold to the crossover or balance tube. On my newer engine the right side hose is just a little longer than the one on the left side for this very reason. Older Rotax 912 engines require the balance or crossover tube be shortened a little to use the method I used. I want to make a better hose clamp but for the time being what I used did work well. The setup consisted of two pieces of aluminum that were compressed onto the balance tube hose using a C clamp to compress the hose flat thus blocking it off.
C clamp and two pieces of aluminum were used to flatten out the rubber hose on the balance tube to block the balance tube. After this photo was taken electrical tape was wrapped around the components to insure no flying pieces from prop blast should something come lose.

 The CarbMate worked OK … but I still would prefer gauges.  The CarbMate only has one row of LED’s so one carburetor is considered to be the reference and the second carburetor is adjusted to match the “reference” carburetor. When the second carb is adjusted to match the reference carburetor, a green LED lights up in the center of the display showing a “happy face”. So you don’t really know what the actual vacuum is for either carb … only that they match or the second carburetor has a higher or lower vacuum than the reference carburetor. So the CarbMate works well for syncing the carburetors, but is not a good trouble shooting tool like a set of good gauges would be.

Based on the advice of a well-known Rotax mechanic, I used a higher RPM of 3500 to balance the carburetor off idle setting. This is because at 3500 RPM the carburetor is no longer using the idle circuit. The carburetor adjustment for off idle was performed first then the balance was performed at idle. All this took a few cycles of starting the engine then shutting down and making an adjustment and climbing back into the cockpit and checking the results.
As can be seen, at 3,500 RPM I was able to obtain a center green “happy face” on the CarbMate TS-111.

After the carbs were synced, the upper cowling was installed and the RV-12 was taxied over to the on field compass rose to adjust the compass.  What’s next? The sky’s the limit.

Carburetor Balancing - A Bust - Literally & Figuratively

Sunday evening, after installing the replacement vacuum gauge (replacement for the one I dropped) on the carburetor balancing fixture, decided to roll the RV-12 out of the hangar and warm up the engine so the carburetors could be balanced.

Prior to mounting the fixture on the piano hinge for the upper cowl, I placed the balancing fixture inside the airplane and ran the vacuum lines through the air vent on the side of the fuselage. The reason for doing this for the first start is … should the needles on the gauges bounce around, the valves in-line with both gauges can be adjusted as necessary to dampen out the gauges.

The plan was to run the engine until it had warmed up and, if necessary, dampen the gauges.  Next take stock of the readings and then shutdown and move the fixture outside and hang it on the cowl hinge then make the necessary first adjustment. Much to my surprise, after starting the engine an initial glance at the gauges showed 0 vacuum on both gauges. What???? That could not possibly be right. Upon taking a closer look at the gauges, one of them was not quite on 0 and I could tell the gauges were being subjected to far more vacuum than the gauges could handle. The needles on the gauges had gone all the way around the face of the gauge and pegging on the stop.

I blame the DOG Aviation procurement department for this oversight … obviously the wrong type of vacuum gauge was ordered. The gauges that were ordered were 0-30 inches of water … OOPS!!! The gauges should have been 0-30 inches of mercury, AKA … in Hg. Duh!!
This is the aftermath resulting from using the wrong type of vacuum gauge. The ones shown here are inches of water and they should have been inches of mercury or in Hg. There was so much vacuum that it internally deformed the internal diaphragm in both gauges.

I don’t know how I let that get by me ... but the end result is I have destroyed both the gauges. Internally, both gauges are severely tweaked and now read over 5 inches of water without any vacuum being applied. The DOG Aviation procurement department has two 0-30 in Hg gauges on the way and they should be here later in the week.

Sunday, October 16, 2016

Replacement ADS-B 470 Receiver Appears To Be Working Correctly

The first task of the day was to install the replacement Dynon ADS-B 470 box. Fortunately, the ADSA-B box is right on top and a snap to install now that the mounting brackets are in place … four screws, a DB-9 connector and one antenna wire later ... and it’s ready to power up.

Upon powering up the Dynon SkyView I could instantly tell there was a change for the better. The SkyView’s display area that shows warnings for items of concern in the bottom right hand corner of the screen no longer showed an entry of “ADS-B In Offline”… a good sign.
At first glance the replacement ADS-B 470 box is working much better than the old ADS-B receiver …. now the box at the bottom right of the screen that shows warnings no longer has an entry for ADS-B In. This is an improvement over the previous ADS-B receiver which had an entry showing “ADS-B In Offline”.

Entering the Dynon SkyView’s setup menus, I navigated to the setup menu for Serial Port 2 to have a look (SETUP MENU > SYSTEM SETUP > SERIAL PORT SETUP > SERIAL PORT 2 SETUP) and was pleased to find the ADS-B 470 receiver communicating with the SkyView … both the RX and TX counters were incrementing, meaning the ADS-B 470 receiver was talking to the SkyView.
As can be seen in this photo taken of the setup menu for Serial Port 2, the RX and TX counters are incrementing and there are zero errors. The bad ADS-B 470 receiver had a RX count of 0 meaning it was not talking to the SkyView.

The next check involved navigating to the ADS-B status menu (SETUP MENU > ADS-B STATUS). This is where the status was previously showing “Not Found” for the bad ADS-B receiver … Now the status field shows “No Signal” which one would expect if inside a metal hangar with the doors closed.
This photo shows the ADS-B status menu now displays the status as “No Signal” … the bad ADS-B 470 receiver had a status of “Not Found”.

I have to say the customer support experience with Dynon was excellent, both from a technical support and product support aspect. The entire turnaround for the ADS-B receiver exchange took less than a week and that was using two day shipping to traverse the US and not overnight. Kudos to Dynon’s technical support staff and great customer service.

I hope to get the carburetors balanced today, if the rains hold off long enough, along with hopefully making a long taxi trip to the compass rose on the field to calibrate the SkyView’s internal compass. With any luck, I may even be able to see some ADS-B traffic displayed on the SkyView screen.

Return from the future: Sunday, after installing the spinner with the newly installed S-1207 bushing, I updated the SkyView map database. While the SkyView was still powered up, out of curiosity, I rolled the airplane out of the hangar to see if the ADS-B receiver could pick up a signal.  It did! So now instead of the ADS-B status saying “No Signal” it now said “Receiving”. Below is a screen shot of the status page.
Once the RV-12 was rolled outside the hangar, the replacement ADS-B 470 receiver now shows the ADS-B status as “Receiving” as opposed to “No Signal”.

After putting the camera away, I thought to check if any weather could be received and displayed on the SkyView map screen. Yep, that worked great! It looked as if it were about to rain and the weather overlaid on the map screen showed moderate rain just north of the airport. Seemed to jive with what I could see from the ground. Unfortunately, I have not see any traffic displayed on the screen yet, but have a good feeling that portion will work fine as well.

Saturday, October 15, 2016

A Week Of Minor Setbacks

Earlier in the week on Tuesday evening Mike T. was at the airport watching his mechanic perform an annual on his airplane and we got to talking about things left to do prior to a first flight and conditioning the brakes was one of the items still left to do. After Mike’s mechanic decided to call it quits for the evening to resume the following morning, Mike gave me a hand temporarily installing the upper forward fuselage skin with a few screws.

It was getting late (almost dusk) and we felt it was a good time to make Banzai taxi runs up and down the taxiway because the likelihood of having other taxing aircraft to contend with would be slim to none at that hour.  The goal for the evening was to condition the RV-12’s brakes as suggested in the Matco brake manual. The DOG Aviation RV-12 was rolled out of the hangar and started. After letting the oil temperature warm up, two fast taxi runs were performed along the long taxiway adjacent to the hangers while dragging the brakes the whole way in an effort to heat them up as suggested in the Matco manual.

After the high speed taxi/brake conditioning was completed, the airplane is to sit for at least 15 minutes to let the brakes cool. By the time the brakes cooled it was, for the most part, getting dark so decided to roll the RV-12 back into the hangar. After hooking up the tow bar and about to push the RV-12 back into the hangar, I noticed the S-1207 bushing was missing from the nose cone. This is the bushing that the pitot tube pokes through on the tip of the spinner …. what the heck? !!! .

Yep, the bushing was flat out missing. The bushing is glued in place using blue Locktite 242 which, at the time I thought was odd, but that is what Van’s calls for in the plans … guessing to make the bushing easily replaceable. Thus far, I have not heard of any RV-12’s losing the S-1207 bushing, so guess this is unique to me. I know I followed the directions precisely and roughed up the mating surfaces with coarse sandpaper as instructed, and even cleaned the mating surfaces with both Acetone and Isopropyl alcohol prior to assembly.

Of course, by now it was totally dark outside and while Mike used his golf cart with lights on to run up and down the taxi area, I was walking around with a flashlight. At one point, I also had a car following me with its brights on and we just could not locate the bushing. So I decided I would call Van’s in the following morning and have a couple of bushings overnighted … so if it happens again, I will have a spare (they are inexpensive $6 each). So prior to heading to the hangar the following morning, a call was placed to Van’s and the two bushings were ordered for overnight delivery.

As luck would have it, the next morning Mike rolled his airplane outside to warm it up for a compression test and his mechanic noticed this strange looking round object on the asphalt and said to Mike “look at this strange looking thing I just found here on the asphalt”. Mike told him it was the bushing from my airplane that we were looking for the previous evening.
The recovered S-1207 bushing that came out of the RV-12’s spinner. Amazingly, it does not look as though it suffered any damage whatsoever. Even so, I will replace it with a new bushings.

I have decided to NOT use Loctite 242 to secure the replacement bushing onto the spinner. I figure the bushing will not come out on its own if I use a glue that is a bit more tenacious.  Silicone was considered briefly, but if the spinner is to be painted, the silicone will certainly guarantee a problem getting the paint to stick in that area. Finally decided to use fuel tank sealant. Granted, it will make replacing the bushing much more of a challenge if it ever needs to be replaced … but I don’t care. The main thing is it will not be parting company with the spinner on its own accord anytime soon … theoretically at least. After scuffing up the bushing with coarse sandpaper, I mixed up a small batch of fuel tank sealant.

I did not get crazy with the fuel tank sealant, just placed a very thin film on the bushing and under the lip on the bushing. Also placed a very thin film of the tank sealant on the inside of the hole in the spinner (this may have been a bad idea from the standpoint of easy removal). After pressing the S-1207 bushing into the tip of the spinner, the tank sealant was spread along the base of the inside of the spinner and then up onto the side of the bushing … theoretically, this should prevent the S-1207 bushing from backing out unless the tank sealant is cut away from the sides of the bushing.
We have been having some cold nights here at DOG Aviation so brought the spinner home so the fuel tank sealant can cure where it is warmer. The S-1207 bushing set on the S-1201 spinner in a thin bed of fuel tank sealant.
The inside of the S-1201 spinner with fuel tank sealant spread around the base of the hole in the spinner and up onto the side of the bushing to keep it in place.

The other setback, which was totally my fault, was breaking one of the vacuum gauges used for balancing the carburetors on the Rotax engine. Yep, dropped it Wednesday while going to a different length of mounting screw and really hosed it up bigtime. Had it sitting on my leg while sizing a screw and it slid off onto the hangar floor and broke the glass cover, along with displacing the movement internally so badly, the gauge is unusable. Fortunately, I was able to find a supplier that had the gauge in stock and had it shipped to me and received it yesterday … so it should not hold up progress. I do want to give the fuel tank sealant two full days to cure, so will not attempt starting the engine until Sunday at the earliest … but Sunday is forecasted to be a rainy day, so may have a little weather delay thrown into the mix as well.

The only shining light of the week … the Dynon 470 ADS-B unit was received back from Dynon late yesterday evening. Dynon gave me an exchange unit under the warranty rather than having me wait for the one I sent in to get repaired. So the project for later today is to install the ADS-B unit and hope it works like it should.