Wednesday, January 16, 2019

Fuel & Engine Tests

Really nothing motivates you more than having an almost complete airplane in your hangar.  If I'm not working, doing family stuff or sleeping... and it's decent weather out (anything sub 40 is not decent) then I'm out at the hangar working on the plane.

The idea of testing something I've put together gives me a bit of anxiety.  I've read countless posts and write ups on the various testing and even began to write out my own test plan based on other people's write ups. In my searches I came across the recently released EAA Flight Test Manual. I assumed this took far more man hours to create by experts knowing what they're doing and for $18 you can't go wrong. Not writing a review on the product but can tell you it helped me wrap my head around some things from what I would consider a definitive source. They're also very clear that your testing actually should build upon this base for your specific project.  For example Yaw Damper testing isn't covered.  So if you have that it should be worked in once you know the plane can fly and land safely.

The first two tests they recommend doing is the Fuel and First Engine Start.  I'm going to apologize I don't have pictures detailing much of this process.  During both evolution's I was too focused on the event themselves rather than taking pictures.

Fuel Test 

I was well prepared for this.  I picked up two 5 gallon Jerry cans, weighted each, put 2 gallons of each and then weighted that.  My idea was I would run those two gallons out time it and then extrapolate the results. That would also give me the weight of any fuel left in the tanks.  That was the idea at least.

I set the nose at about 5% nose high.  I've seen pictures of people putting their plane in all sorts of pitches to ensure it runs.  That's probably important for acrobatic tests, I'm going to guess it's not needed on a cross-country machine as it also wasn't suggested in the EAA Test Cards.

With the plane set up and the fuel line disconnected from the mechanical pump I was ready to get to test.  With the bucket and timer set I hit the boost pump.  It kicked on right away and... well nothing.  No gas, didn't seem like any air was running out.. a big flat zero flow.

No gas, is no good so I got to troubleshooting.  Did everything from switching tanks, to checking lines to adding more fuel (throwing off my scientific weight tests).  I ran low pressure air up through the system and confirmed not only was the fuel selector correctly plumbed but there was no type of blockage.  I fiddled with things more having no luck.

I made the assumption that given the low wing nature and that the pump hadn't been run with fuel that it was as they call it 'airlocked'.  I ended up using a shop vac to suck some fuel out from the front.  Put the pump on and walla! Fuel! ummm lots of it.

Because I was turn on and turn off the boost pump at this point I had given up on timing anything.  I also spilled a bit of fuel at the wing root, under the seats, ect... so my weights would have been off anyhow.  I let the pump run on the right tank for a bit, along with the fuel there was an oily mess that I assume was from the pickling of the boost pump.. may or may not have been an issue on the initial priming.

For the other tank I did the timing and ran it for exactly 1 min. Weighted the contents minus the bucket and came up with close to 7 pounds.  Extrapolate that out and it's roughly 60 GPH.  Per the EAA guide they recommend 150% of your max anticipated fuel flow.  The lycoming manual provided some ranges and the max I saw was 28 GPH so I needed to be at least 42 GPH which I was above so I called it good.

Should also not that I had no leaks until I connected it all back up and ran it through to the servo.  I apparently forgot to double check the servo connection so it pissed some fuel out past the nose gear.  Once that was tightened again no leaks and was getting ample fuel pressure.

Now I have to revisit the usable fuel test.  At this point I'll run both tanks dry and measure what's left via volume instead of weight.  I don't anticipate much given others experience with the RV-10.

First Engine Start

After another few weeks of hangar sessions it was time to test the engine for the first time.  Hey at least I know it has fuel! Everything else, not so sure on.  I reached out to my local A&P to get assistance from him and his shop.  I also had some questions I wanted to bounce off of him and as always he was extremely accommodating.  If you ever need a shop in the Oklahoma City area I highly suggest Brian Butler and his guys at Reliable Aircraft Maintenance out at KHSD (Sundance). These guys are the best hands down!

Okay back on track, Brian and his crew looked over the engine and got it ready for the first start.  Unfortunately the starter wouldn't actually spin the bendix. It would extend as it should but then just "click-click-click."

Worked with Brian, walking through things I wired up and how certain parts were connected.  It ended up being the ground I hooked directly up to the Starter on apparently the wrong place. So if someone tells you to hang a ground off a Sky-Tec starter where there's a boot covering the black wire... they're wrong.  You could probably hook it directly up to one of the other holes on the starter but I decided to just bolt this ground directly to a close by engine bolt, away from any arcing danger. So now I have dual engine grounds!

We finally got the prop to start spinning. They ran it through with the bottom plugs to build up oil pressure and that's when the next issue occurred.  My oil cooler actually had a small really hard to see pin hole in it. Called Bill from Airflow Systems and he's sending me a replacement, even offered to do next day.  I declined next day as it's about to get sub 40 which means I'm not working on plane stuff unless it's either inside the plane or homework activities. The leak isn't big and no clue how it happened but in the end Bill stands by all his products and is always great to talk with.  We just threw a connector on the two oil hoses so we could continue with the engine start, minus the oil cooler.

We did a series of three starts actually.  The first start seemed a bit high on the RPMs so he shut it down in about 5 seconds.  Made some throttle adjustments and ran it again, this time I couldn't find the RPM so we instead tested the alternators and looked at what was showing up on the EFIS.  This run was about 30 seconds.  I went into the G3X configuration and changed up the RPM settings and alternator screens for the last run.

The last and longest run was about 3 mins which was the max I wanted to go.  Even though this engine spent time on a test cell I still plan on using ground runs very sparingly.  Engine started great, EFIS engine readings were solid minus RPM (Now know I put the sensor on the wrong part of the mag), Alternator Shunts (Emailed the Garmin folks to validate how it should be set up to see amps, volts were showing correctly but 0 amps).  The most important part was the engine ran, nothing blew up and it was drown right amazing to see it all!  Here's a picture of technically the first spin, with the plugs out to build up oil pressure.








Wednesday, January 2, 2019

Rigging

Happy New Year! It's cold outside which by default makes it a non-build day.  So I thought I would do a quick update on where I'm at with rigging.  This is something I've worked with on and off since I attached the wings but I wasn't particularly happy with it so decided to start from scratch and follow a process.  Should also note the plans come with a very handy table in Section 5 that state the distances in degrees that your surfaces should move. This is handy to ensure you have enough travel.  Here is the order I did everything in:

  • Elevator - I started by working the elevator rigging so I could lock pitch in neutral for the rest of the rigging.  Problem encountered was that my control stick was hitting the front panel.  It was just barely hitting since I could put a bit of roll in the controls and it would stop just left or right of center.  Either way I needed to put a bit of a bend in the sticks to allow full movement. Now the controls are all free and clear, with the only obstructions being my legs or crotch.  Once the elevator was set I locked it into neutral via some tape and moved on.
  • Flaps - I wanted to ensure my flaps were set correctly even though I previously set them.  Using my digital level I wasn't happy with my angle.  You're looking for a 3 degree reflex on full up position.  This is also when the flaps are even with the bottom of the fuselage.  I think I ended up with about 3.2%.  The difference is so minimal that I doubt it mattered.  Also you'll want to put a bit of upward pressure because in flight the wind will be doing that.  Takes a bit of fiddling but with the VPX you can adjust the stop point rather than tweaking the control arm.
  • Ailerons - The Ailerons should be in line with the flaps.  I double checked they were in the neutral position with the template you get from vans.  They were and in fact they were inline with the flaps and fairly close to the wingtip.  The right one was a bit off, not in neutral position but where the control rod connects on the root.  I remember doing this solo and it was hard to get the template in the wing root and adjust the rod.  The solution was to lock the left aileron with a clamp.  Then the right one, ensuring it still in neutral position and then make adjustments on the rod end.
  • Rudder - For good measure I'll include connecting up the rudder which really only involves making a set of brackets.  You have some choices from 1" - 2.25".  Not knowing what I really wanted I made a bracket out of aluminium with hole spacing to accommodate 1"- 2".  I decided for me who likes to have full rudder authority that 1.75" was the best spacing.  That allows me to have solid rudder control without having to have the seat pulled all the way forward.
I'm sure you could spend a lot of time trying to get everything within a 1/10th of a degree, or exactly aligned.  Anyone who has ever done a preflight on an aircraft will point out there's a bit of play on these surfaces.  The plane will find it's equilibrium, you just want to help as much as you can to ensure your first flight will be straight and level as possible.  You can always go back and tweak things during Phase 1.






Thursday, December 20, 2018

Wing Attachment

Section 44
The wings have actually been 'attached' for several weeks at this point.  I had also done substantial prep work in my garage working with making the wing root fairing supports and the upper wing root fairings.  I honestly though the rest would fly by pretty fast, however that was not the case.

Being the first time to ever attach wings onto a plane I figured I would diligently follow the steps in order, and sticking to the plans... well that didn't last.  My major concern is once you put on the wings the plans have you pull them back off to do some attachments and what have you.  Then you push them back in for final bolting.  Given the importance of the wings I didn't like that idea, instead I decided to push the wings on and bolt them all down so all my match drilling and what not would be solid and not shift around.

The problem was that I made everything a bit harder going this route.  A lesson learned is I should of drilled the hole for my Pitot/AoA tubes before putting the wings on.  That made this a bit harder.  Also I should of gone ahead and riveted on the wing root fairing supports.  That also became a challenge with the wings attached.


The biggest time-sink by far on this section is all the drilling, match drilling, nut plates, putting on parts, taking them off, putting them back on ect.  You also spent quite a bit of time sanding.  You have to sand the inboard edges of the flaps so they fit, you also sand the top and bottom fairings so they fit.  It's not hard, just time consuming.

With the wings attached, and all related parts done I was able to finish wiring routing of the wings.  My conduit works out fantastically and was about perfect on size.  I had to get creative since I'm putting my OAT by the first access panel on the left wing.  This involved drilling a hole in the conduit and fishing the wire so it come from the cabin to that spot.  I did the same on the right wing for the trim and trim sensor wires.  This kept wires in the conduit and out of the ribs.  Below is a picture of the root after I dressed the wires.




Wednesday, December 12, 2018

Paperwork & Progress

Paperwork

I've really shied away from creating any sort of timeline pressure on this build.  I've always wanted to be able to work on the project, or if I felt like it, not touch it for weeks at a time.  However that is now over as I've submitting my initial paperwork to the FAA and the clock is ticking!

I dug out the 'Step-by-Step Certification Guide' that had been sitting in my office for the last 3 years and gave it a look through.  Not sure if EAA still offers these, but for the $12 or so it cost it's well worth it.  You can find similar information out just searching but the guide shows you examples and literally is a checklist for the process.  In short here is what I sent off the to FAA:
  • AC Form 8050-1 Aircraft Registration Application: This came with the above mentioned EAA guide, however you can also go to your local FSDO and pick one up. If you've ever bought or sold an airplane it will look familiar.  Whatever information you put on this will need to match your airplane info; builder, serial, model.  For me I kept it pretty basic (Last Name, First Name, Builder Number, RV-10)
  •  FAA Form 8050-2 Aircraft Bill of Sale: You request this through Vans ensuring you give them the same information you're using on the 8050.  It all has to match.
  •  FAA Form 8050-88 Affidavit of Ownership for Amateur Built Aircraft: I downloaded and filled out this form.  It has to be notarized as well.
  • $5 Check
Make copies of the above and mail to the FAA PO Box on the forms.  Being local I took it to the actual post office where the PO Box is.  I still had to pay for shipping but I assume it made it to the box safe and sound. It's suggested you give them around 90 days to process this through.  I'm aiming for a March/April first flight so my plan is to submit the next batch of paperwork (Special Airworthiness Certificate) in about a month.

Progress

With the weather getting near or below freezing I've not been going to the hangar on a daily basis as I did the first week.  That hasn't slowed me down because on top of doing paperwork, planning and ordering odds and ins I've been doing my 'Homework'.  In fact one of my homework items was to finish up lights for the wing tips and clean up the empennage fairing.

This, as with most fiberglass was a fairly tedious cycle of sanding, filling, sanding, ect.  Particular to the wing tip lights there was a lot of sanding to get the cutout hole the exact size without having it too large. This is done with 150 grit or so slide between the light and the side and just worked around until you have the spacing you want.  Because of the temps I had to move the project out of the garage and into the kitchen so everything cures correctly.

My only complaint is the CS pull rivets were not long enough to capture the inside mount.  This was mainly due to me building up the inside of the tips for strength.  So it's not as smooth as I would like, however once painted I doubt it will bother me at all. Will be taking these back to the hangar now for future wiring.


Onto hangar activity, I was able to take advantage of a few warm days to work on wing attachment items as well as final fitting the empennage fairing.  I am just about done with all wing attachment steps but will make a separate post with pictures once I'm complete.  I will however show my variation from the plans with a really good looking aftermarket vent from JD Air.

The problem I was trying to solve was around fuel vent freezing.  If the vent freezes it stops the air into the gas tank which restricts the tanks ability to feed fuel to your engine.  That's bad!  I was talking to Tom with TSFlightlines about this issue and was thinking of using a check valve or something.  He directed me over to JD Air who makes a vent that helps mitigates this problem by having two openings.  Not to mention it looks really slick.

Installation was extremely easy, you just install it to your wing root bottom piece and then bend some 1/4 tubing to connect it all.  I had tried to avoid ever making lines but Tom suggested instead of spending $45 on braided lines to connect this that a rigid line was best.  Having excluded this material from my kits I went to Ace Hardware and picked up two 12" sections of aluminium tubing for $1.80 a piece.  I then swung by Harbor Freight and picked up a $10 bending tool.  That along with my 30+ year old flare tool I was able to make some solid first time vent lines which fit perfectly.


Another item I've spent some time on is the empennage fairing.  I've become a bit obsessive compulsive on fiberglass work.  From the factory I was happy with the fitting of the fairing and there was a good 1/4 gap between the front of the horizontal stabilizer and the fairing piece.  I was able to essentially force it into place but it then required me to rebuild a few of the edges a bit. I also deviated from the plans in terms of attachments.  For example I tapped all the holes on the bottom for #6 screws which include the ones that tie into the vertical stabilizer.  I also didn't dimple or countersink any portion that was under the fiberglass.  For whatever reason there are several holes that the plans ask you to countersink but are covered with fiberglass, which is counters sinked so the piece behind it can be flat.  The picture on the above right shows the gap fairing which turned out well.

I am 31 nut plate installations away from completion of the empennage section.  I need to work on some rigging items, connecting the rudders and such but rigging I consider it's own little thing.  Here's a good picture of where it sits now.



Sunday, December 2, 2018

Final Assembly Progress

I've been burning hot on the project since the hangar move last week.  Over the course of 7 days I've been able to rack up 32 hours of solid progress towards completion. The airport is a good 25 minutes drive which forces me to be more organized on my work session planning. Because the plane, tools and parts are no longer collocated in my garage, I've been taking things back and forth.  At this moment I have the wing tips, landing & nav lights as well as a trimmed, fitted empennage fairing all ready for some finalization.  I'm going to save that for later this week when the weather gets below 40. My garage is insulated, my hangar is not making the garage the preferred cold weather activity spot.

Over the last 7 days I've taken a ground zero approach and started moving through the plans per section ensuring items have been completed.  As mentioned last entry I had already noticed some things that I didn't do for whatever reason.  I worked all the way through the empennage section through attaching the fairing.  I wasn't happy with the fit and trimmed a bit too much off in some places so now I have some fiberglass work to do along with some nut plates and that section will be 100% complete.

With the wings everything checked out and the only pending items are around the AeroLED light installations. I had modified the wing tip just over two years ago.  So once I complete the homework of installing those, the wings will also be done.

Onto the fuselage there really wasn't anything that I hadn't already done in the garage for most the sections. In the second to last section the only outstanding item involves riveting the forward tail cone top skin.  This is still pending some Air Conditioning items so that's on the side burner and will more than likely be one of the last items completed. The last section however is also the most exciting item of this update involving attachment of the wings. I didn't struggle with this as much as I thought I would, having at least another set of helping hands is a huge benefit. It really deserves it's own log update so once I'm finished up I'll post more later.  I have just a handful of steps left, mostly around nut plate installations.

Once I wrap up the above, my plan is to go through both the finishing and firewall forward sections.  As with above it's to ensure completeness and that I hadn't inadvertently missed anything.  Just flipping through them though there's little if anything that I'll need to do.  Then the focus will be purely on finishing non-structural items in preparation for inspection.

Sunday, November 25, 2018

Moving Day & Final Assembly

Hangar Move

After over 3 years of N10JW living in my garage it was time to do the big move. I had completed a majority of my Hangar Move punch list with only the Air Conditioning items outstanding.  I didn't want that to hold up progression so I made the call to go forward with the move.

The same friends that loaned me a truck last year and helped hang the engine also happen to own a Roll-Back which is a perfect method for moving the chassis. In preparation I pulled her out to my drive way for a couple photos.



Once Andy got here we talked a bit about it and figured out the best way to pull the plane onto the truck. The plane has an incredibly wide wheel base compared to your average car and we determined there was about 3/4" clearance available on each side.  We also decided it would be best to go ahead and remove the wheel pant mounts from the wheel nut to avoid any damage.  Once that was done I lined her up and actually laid under the fuselage with a tow bar attached to stear her while she was SLOWLY winched onto the truck.





Now Andy has some plane part moving experience.  He also helped me about a year ago when I moved the wings and the horizontal stabilizer to the hangar.  After looking things through decided it was best to do an additional strap on the nose gear, one on each main that would cross and another around the steps to hold it all down.



Moment of truth came and we pushed on the 20 mile or so journey to the airport.  It's a pretty funny sight and being the chase car I enjoyed watching people's reactions to what they were seeing.  We also drove no faster than 50 MPH on the highway.





Unloading was a lot easier than loading.  We had her off the truck and in the hangar in about 5 minutes.  It was a HUGE relief to have that safely done and quite a project milestone. 


Final Assembly

I would imagine its hard for any builder to do that move and then just lock up and go home.  I had come a bit prepared and brought a number of things from my garage with me so I could get a bit acclimated to everything. From a work prospective, still working off punch lists I now have it divided into 'Final Assembly' and 'Home Work'.  Some things like say the wing tips, I can finish up in my garage, while other things like the obvious wing attachment have to occur in the hangar.  My plan moving forward is before every work session I'll write out the things I want to get done, review those planned elements and ensure I have the tools and parts needed to do them and then head out to the airport.  Make notes, lists, ect. prior to coming home.  Rinse & Repeat and I'm expecting to make fast progress.

Not wanting to wait on progress I decided to started on the first task of removing tape and other protective coatings that I had left on.  After that started with reviewing each page of the plans, one by one and ensure the all steps had been done as I'm now able to go through the plans and complete things that I skipped previously.  Didn't take me too long to realize for whatever reason I left out two rows of AD470 rivets on the Vertical Stabilizer for whatever reason.  I assume I might have thought that it got rivets to the tail-cone skin seeing two rows pre-punched holes on the aft part, which I now know were used for other rivets.  So I had circled this step, put my VS up in my garage and forgot about it the next 3 years.  Given that I didn't bring my #30 bit I was quickly at a hard stop. Not to be beaten I used the time to remove the wingtips so I could bring those home and organize my hangar a bit better.

I did however take a picture of N10JW prettied up a bit!

Thursday, November 8, 2018

Ram Air Servo

Sometimes it's fun to overly complicate things just to have cool buttons to press!  This was the case with the actuating function of the Ram Air.  The kit comes with a bowden cable you can run to your panel.  I'm sure that works great but I felt I really needed more buttons to push in flight so I pushed forward looking for a solution.

The switch requirements are the same as my cowl flaps as it requires just swapping of polarity to extend and retract the actuator. The actuator itself is a L12 Linear Actuator 30mm 50:1 12v. 30mm is the throw and the lowest it can be.  I did some measuring and it seemed to me that would work fine. 50:1 is the gear ratio that is essentially the force to open and close.  I'm going with this one first and if in flight I find it needs more force for whatever reason I can replace with a 100:1 or more.  wiring that swaps polarity between the two switch positions.  Since I resolved that with the cowl flaps that was the easiest component to this.

My dilemma was trying to figure out how to work the actuator arm on the canister in a somewhat cramped space, which running the arm the full throw of the servo. I tried various things such as replacement arms, changed brackets and even remotely mounting the servo somewhere else.  The only other person I talked to who had done this mounted his servo in the tunnel and ran the bowden cable there.  If I end up with heat issues I may have to go back and do that.  But for now I tried to do a self contained unit.  I won't bore you with my trail and tribulations so here's what I ended up with.

Canister prep was basically attaching a small piece of bowden cable and adel clip.  I expieremented on different holes and in different orientations.  What I found worked the best and didn't interfere with anything was to position the arm for a downward movement, run the bowden cable down and to the side to allow me to mount the servo on the bottom of the unit.  Far from the engine, exhaust and other heat elements.


Then I made a bracket to mount onto the canister that would allow the actuator enough space to move a very small piece of bowden cable.  It's about 3 inches wide and hand formed to the curve of the radius of the canister.  I then drilled 2 holes down the center, with the mounted point to match an existing canister hole.  Then I spaced to additional holes an equal amount apart.  Lastly I put some foil tape on the back to help as much as I could with heat.



 I did a test run and found the actuator pushed up vs pushing the cable.  The actuator came with two little clamps, having no idea what they were used for I just ignored.  Then it occurred to me that these are to mount the actuator so it wouldn't move. Fortunately me I happened to space the two hole out in just the right spot that these could be attached to the bracket screws.


I re-purposed some connecting hardware meant for the carb heat (Which I don't have) as well as safety wired everything up.  I mounted the unit fairly painlessly and used a molex connector for the wiring.  Checked the cowl spacing and gave it a quick test. As you can see in the video it works well.  It doesn't close as much as I would like, however I'm not overly concerned with anything getting through that space.  If it poses a problem I can upgrade the servo to a 100:1 or more to get something with a bit more pull/push strength.  I'm going to wait though to see if heat becomes an issue as well before I do anything like that.