Monday, April 25, 2016

First Flight!

Today was the day!  (well, yesterday.)

After much wringing of hands and double checking and running inspection checklists, I finally committed to actually flying.  I had a support & photography staff of 3: best friend Dale and his wife, Carol, and Dave R, whom I met when he started his own RV-12.   (My wife wanted to know about the flight after the fact.)

Overall, the flight went almost exactly as planned, and with no unexpected findings or upsets.   I made one more high speed taxi test, actually on runway 28.  I used full throttle for the first time to verify that full torque did not produce unmanageable behavior.  Taxied back to 28 (and then back-taxi to reach the actual departure end, since there’s construction in progress) then took off with 0° flaps.    Climb was positive and smooth, at well over 700 fps at about 75-80 kts.   Airspeed and groundspeed agreed as expected, but quickly diverged at altitude, with a much stronger than expected wind from the south. (I’m not sure if that’s real or an artifact of a poorly calibrated airspeed.  The wind vector was pretty constant as I circled (15-18 from South), so it might have been real, but it’s still something to keep an eye on.)

I initially thought I had a heavy left wing, but it was actually very very well balanced in roll.  I think the stick is a touch left-of-center when the plane is straight and level.  If so, that shouldn’t be too hard to correct when I do the 1st inspection that calls for removing the seat pan to get at the linkages down there.

The over-the-nose visibility is excellent, even compared to the Cardinal (which has pretty good visibility of its own.) As a result, I had a tendency to hold too much nose up and I climbed well above my initial intention (quite arbitrary) of 4000’ and eventually ended up at 6000’.   Turning response was smooth in both left & right.  The electronic ‘ball’ was relatively insensitive, but quite usable.  This was the 3rd time (1st two were in DG’s RV-12) that I was flying behind all glass, and I could tell that it would be some time before it was 2nd nature.  Luckily, this is a plane that is all about keeping your eyes out of the cockpit and looking out side and flying by the seat of your pants.

Descent to pattern altitude was unremarkable from an airframe perspective, but I did note the infamous throttle creeping behavior associated with the springs in the carburetors.  Even with the friction lock fully tightened, the throttle can easily be turned using the vernier mechanism.  I think that the vernier ‘creeps’ due to the engine vibration and the springs.

I made a low pass over 28 and then executed a balked landing in order to get a feel for the pitch changes associated with that maneuver.  There weren’t any.  OK, now if I need to abort a landing, I’ll have done one before.  Set up for another circuit, and made one of the nicest landings I could ask for.  The idle stops are set a tad too high, and I couldn’t get less than 2500 RPM (1000 prop RPM) on approach, and that led to a long, long float before she touched down.  (I will have to set the idles back far enough that the engine probably won’t run on the main carbs when cold, but that’s exactly what the choke circuits are for.)

Taxied back to the hangar, got pats on the back from my friends, and buttoned up the hangar.  I didn’t write down any of the numbers on the flight card out of the Product Acceptance Procedure.  I’ll download the black-box data next week (next opportunity to get to the airport) and fill in as much as I can, and then do a very thorough post-flight inspection.

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ready to start

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taxiing out

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perfect day!

video, courtesy of Dave Rohrlick 

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RV Grin!

Saturday, April 23, 2016

the "Golden Spike"

(Well, it’s some aluminum plates to be honest, but you get the idea.)

There’s nothing left to do.  Fuel tank is fixed.  Engine is sync’ed. Cables are tight.  Paperwork is in order. Prop is pitched.  Tonight’s task was to put all of the loose pieces back on the plane to make it actually airworthy.  It took about 2 hours.  The lower cowling is ‘tight’ after the engine remove/re-install, but I got it back on without any cussing or drilling.  Upholstery went well in front and in the mid section, but I discovered that you can’t get the upper bulkhead cover back on without removing the fuel tank.  Not today!  I’ll leave all of the carpet out of the back for now.

The ‘blue flower’ you see below represent the last items to be installed to make the plane “complete”.  Yes, there are still things to do (wheel pants, AoA sensor, etc.), but these 5 access panel covers are the last items out of The Book that need to be installed.   It was with great pleasure I removed the final bits of blue plastic and went to work.


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the last pieces to install 


Here’s a selfie of me installing the last access plate.  (Phone is sitting on my chest, activated w 3 sec delay from my watch).

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 Installing the last part


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All done.  Only thing left to do is go fly.

Leaks sealed (i think)

I called Van’s the other day and went through my options.  They were happy to do warranty work, but I didn’t want to spend the time to ship the tank to them, wait for them to repair it, ship it back, etc.   Not to mention the shipping costs.  They did send me 3 oz of Pro Seal, which I used last Thursday.  I elected to remove the face plate, rather that drill out all of the rivets for the top again.  Although I did OK the first time, I’m very cautious about drilling rivets—there are always some that get oversized holes and that’s just an opportunity for even more leaks.   The front piece is screwed on and is designed for maintenance, so that’s the way I went in.

While I was on the phone with Van’s, I was asked about the serial number.  I said ‘none’, but when I was removing the face plate, I realized that there was a number engraved on the front:  “385B 13/09”.   I’ll have that ready for tech support if I need to call them again.

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It was a bit challenging to get to the back of the tank, but I got the majority of the old sealant out of the inside of the corner.  I do note that there are no scuff marks as called out by the assembly instructions.  That was addressed with a straight wire brush on a dremel extension.  Inside corner got gooped; face plate got gooped and tightened, then the outside corner was scraped, sanded and cooped.

I didn’t get nearly as much of a bead of sealant around the plate (compared to the factory seal) when I reattached it.  I’ll watch it carefully, as that’s all I can do.   The tank was cured for 36 hours at 85 °F (guest bathroom with a space heater).  During the meantime, I looked up the technical data sheet for the stuff and was greatly relieved to see that it’s officially ‘cured’ at 4 hours (although the testing is done after 14 days at 77 °F and 50 % RH.  Go fig.)

Tank was reinstalled (30 min), plane refueled with 8 gal.  No visible leaks.

Ready to roll....

Sunday, April 17, 2016

3rd Leak!

Now, I’m really annoyed.   Here’s what the tank looked like after I pried off the top (before I cleaned up all of the debris of cured ProSeal.)

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 inside of fuel tank

I sealed up the left lower front corner and the right upper front corner from inside & outside.  I resealed the top.  I took it home and put in in a small bathroom with a space heater to keep temps above 80 °F x 48 hrs to help accelerate curing.  I took it back to the shop and filled it to overflowing with gas.  There was a much slower residual leak at the right upper front which I then re-applied external PS.)

OK, now everything is looking good.  Tank gets drained again, re-installed again. Tank gets filled, didn’t see any leaks.  Spent a few hours doing taxi tests, ,tweaked carbs’ sync, did a static run up (5300 RPM), did brake tests, and aligned the digital compass.  (Also discovered that the heater door doesn’t close all the way.  Very effective heater, especially in a 75 °F day!)   All in all, it was  great progress.  I seriously considered 1st flight the next day.

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misc engine tests

Today, I opened the hangar to discover fuel on the floor!  Sure enough, there’s gas on the inside of the plane.  Last time, I was very fast to defuel the plane to stop the draining.  Today,  I took 5 min to really see if I could find the source. As I recalled—and confirmed today—the leak appears to be left (medial) rear lower corner since there was gas on the inside of the baggage compartment, plus a bead of gas running down the left lower edge, thence to the outside of the fuel feed / fuel return and  a mess all over the inside belly skins.  Upon tank removal, there was no gas staining on the right (outboard) side at all.

Now I’m stumped.  A full fill test x 2 hrs showed no leaks.  I know I triple checked the left lower rear corner because I suspected that was the source when I pulled it last week.  The only thing that came into my brain was “what’s the difference between being in the plane vs. on the bench?”  The answer is “mounting.”  In the plane, the tank is suspended by 3 bolts (1 AN4 at the back; 2 modified AN3’s in the front.)  This puts the floor of the tank in tension.   On the bench, the weight of the tank is pressing down on the floor, so the floor is in compression.

I rigged up a quick suspension cradle with some light chain and a few bolts.

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gas tank suspended to emulate in situ mounting 


Viola!  After 7 gals of gas were added, there’s a clear leak, right where I expected:  left rear lower corner.

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leak #3  at left rear lower corner

Now, what to do?  I’ll call Van’s in the morning to discuss getting a new tank.  With 3 leaks, I really don’t feel I can trust this one.  On the other hand, I want to get airborne as quickly as possible.  I suppose I can remove the face plate of the tank and reach back there to clean and re Pro-Seal from the inside as well as the outside and hope for the best.  (The extra time to do that doesn’t bother me, since there’s a 48 hr cure time.)  On the other hand, if Van’s will swap me a tank quickly (unlikely, as I don’t think they have any stocked), that would be great.  I’ll find out tomorrow.


Saturday, April 9, 2016

not one, but 2 leaks!


I pulled the tank yesterday (I’m embarrassed to say that I’m getting pretty good at it) and started hunting the leak.  I recall seeing fuel all along the medial (left) lower edge of the tank and that it was running down/forward along that edge from the rear to the front.  That made me suspect that I would find a leak somewhere near the back.

I rigged up the ballon and bicycle pump as per chapter 37, but was unable to find any leak.  I know that pressure was escaping, as the little ballon became slightly inflated, but then deflated in about 5-10 seconds.  Despite that, I couldn’t even find where air was escaping.  (I suspect the fuel cap.  Despite plugging the vent hole by tapping it 4-40 and filling it with a locktite covered screw, I just don’t think that the fuel cap itself is air tight.  Even with duct tape.)

Moving into a more aggressive mode, I capped the main outlet and proceeded to fill the tank to nearly full;  Viola!  Not one, but two leaks.   They are no where near the magnitude required to have created the mess I found last weekend.  I will have to chalk that up to an inadequately tightened main fuel line fitting and will double & triple check that stage when I get there again.  During the meantime, I have two small leaks to deal with.


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Fuel leak: lower left forward corner


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 Fuel leak:  upper right forward corner

I’m firing off a “how do I fix this” question to VAF and will proceed with the advice of the collective.

Sunday, April 3, 2016

fuel tank leaking

Damn.  I’m really getting tired of these setbacks.  Yesterday was a pretty good day for forward progress.  I bought 18 gal of premium mogas and went through the fuel calibration procedure (putting the rear wheels on 2” chocks to emulate normal flight attitude, telling the Dynon each time I added 2 gal). There was a little bit of spilling, enough so that the odor of gas was to be expected.

Today, I went out to check for leaks and found much more than I was expecting.  Based on the float gauge, maybe a gallon or two leaked out overnight.  Looking up at the main fuel connection, I found that the fuel was coming from above that spot.  Climbing up into the plane itself revealed a touch more information: there was about 1/2 cm of fuel wicking along the medial lower edge of the tank, thus implying that the leak may be on the rear medial seam.  I didn’t do much trouble shooting beyond that, so further investigations will need to wait until next weekend.

I put the nose wheel on a 2” block to make room for the large 7.5 gal transfer cans and removed the valve from the gascolator and used the pump to drain the tank as well as possible.  (Learning from yesterday, I paused near the end and put the rear wheels on blocks to get a bit more drainage from the tank.)

I’ll have to remove the tank (again!) and figure out where the leak is next weekend.  

Friday, April 1, 2016

split bulkhead modification; flight training

The fuel tank is empty, and I want to fill it up when I do add gas (to calibrate the EFIS).  The urge to take advantage of the currently empty state was too much to resist, so I pulled the tank yesterday in order to install the split bulkhead modification released by Van’s last fall.  (Ironically, they released the mod about a week after I gave up waiting for it and installed the tank and closed up the tail.)  It actually wasn’t as hard as I remembered: I thought to myself, “I must be getting better at this.”  I can confirm:  I had to pull it again today. 

Page 33-03 rev 2 starts out by calling out dimpling of all of the #40 holes in the smaller piece.  Unfortunately, the piece that I received had not been drilled.  I decided to just use the large piece as a template and drill my own.  Unfortunately, I didn’t think it all the way through.  I lined up the outside edges of the pieces as my reference, neglecting the fact that there were predrilled holes along the left edge (in the picture) where the small piece attaches to the aircraft.  I was so proud of my accomplishment that I installed the tank (and all associated plumbing) before I went to attach the large piece, only to discover that the custom holes that I had drilled were off by about 1/8”.

I removed the tank (again) and pulled out the offending piece and prepared to order a replacement from Van’s.  I then realized that I could salvage the situation by taking the now-surplus original bulkhead and cutting out a replacement small piece.  To ensure a better alignment, I took the new small piece and the large piece and attached them to the airframe and went to drill in situ.  The next minor set back was that there wasn’t a back stop to hold the work in place so the drill bit could bite.  I had to reach behind the large piece and hold the small one with my hand while I drilled. This introduced a touch of distortion, but I was able to make it all work.

BTW, I picked up crow’s feet wrenches a few weeks ago.  Should have done so last year!  They make installing the fuel / fuel return fittings much, much easier!


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New split bulkhead


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Split bulkhead with tank installed 


The Product Acceptance Procedure has a nice write up on how to approach Maiden Flight.  One of the pieces of advice was to get some upset recovery training in a similar sized / powered aircraft.  On a whim, I called the local FBO and got a lesson in this Evector LSA.  Today was pretty windy, and I actually felt pretty queasy by the time I was done.  i’ll definitely get another hour or so in the Evector before Maiden Flight.  (I’m tentatively looking at 4/16!)


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