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Painted!

Finally got 313TD painted.  It was time.   The salt-laden dew at SMO was killing the skin, especially underneath the canopy cover.  I hemmed and hawed over various paint scheme ideas, mostly military-themed.   Eventually, that gave way to the practicality of painting it to make it more appealing on resale.  But then I thought, who am I kidding, I’m not selling it, it’s too awesome.  Then on the way to work one day, I saw a BMW M4 Gran Coupe, painted in Singapore Grey Metallic.   I have never before been so captivated by car paint.  The way it captures the ambient light and the prismatic effect of the metallic flakes is fascinating, and the pictures really don’t communicate the full impact of how it works with light and reflection.  One could argue there aren’t enough swoopy lines in the body to make it work right on this structure like it does with a sport sedan’s bone line, hip line, and fender contours, but I disagree.  you really have to see it in person.   In any event, I’m happy with it.   Not only is it protected from the elements, it looks bloody awesome.  The gear fairings and wheel pants still have to be put back on, but since I ordered a set of pre-made RV Bits fairings, I’ll need a facility to install them so I can get the alignment right.   The wheel pants are also gloss black.

Big shout out to Derek Spears and David Prescott, who helped with the movement and various aspects of disassembly/reassembly!

In the hangar, you can see a bit of how this paint is supposed to work.  Right now it’s picking up the greenish hue from the fluorescent lights and the yellow-green skylights, but also the blue bounce from the floor near where the hangar doors are slightly open.

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Indoors

It’s a dark gray, to be sure, but the way it phases through the blue-green spectrum is awesome, and the black just sets it off.

Here I am, set to head back to Santa Monica with no pants on.

Direct sunlight really does a number on photographing this paint, but it’s still amazing!

Paint!

I dropped off the plane for paint today in Chino at Century Air Paint.  The process involved removing all control surfaces and fairings.   But along the way there was some, uh, stuff, mostly having to do with wires that needed to be cut.

  1. Tail lamp and strobe:   Will need to be reconnected.   Need strobe wire molex and pins.  Or barrels.  Need to look that up.
  2. Elevators: Need new set of DB9 socket barrels for trim tab motor control.
  3. Flaps:  Look at platenut options, because drilling out the pop rivets for the hinge pin retainer fooken sucked.
  4. Need to repair/resolder ground wire on red nav light board
  5. Will need to drill/realign gear fairings to fit new intersection fairings.
  6. Need new MR16 ceramic bulb connector for nav light.
  7. Anti-chafe tape (forgot what it’s called) – for underside of wing skin where flap rides
  8. rubber grommets for strobe/tail light
  9. rubber grommets for trim tab wire

Some tools will be needed for this op:

  1. #40 bits
  2. #30 bits
  3. Flush cutters
  4. AFM8 crimper
  5. multimeter
  6. Red and blue inline wire connectors
  7. Connector crimper
  8. Extra wire
  9. The usual aircraft tool container
  10. Need new MR16 ceramic bulb connector for nav light.
  11. Anti-chafe tape (forgot what it’s called) – for underside of wing skin where flap rides
  12. rubber grommets for strobe/tail light
  13. rubber grommets for trim tab wire
  14. 8R8 platenuts, single sided
  15. Functional #40 size Cogsdill deburring tool
  16. #30 size Cogsdill deburring tool

Hopefully this list will allow me to put back all the things I took off, then fly it home after the paint job.   If you’re wondering about color, it’s going to be BMW Singapore Grey, with black tips and spinner.  Like so:
2013-bmw-m6-gran-coupe-singapore-grey

Full credit for the photo goes to Performance Drive, and you can view the full article here:
http://performancedrive.com.au/2013-bmw-m6-gran-coupe-review-video-2206/

 

No More Wobble.

16 hours.

Going to have to sum up last week as well.   Last weekend I did the fiberglass layups on the intersection fairings.   I hate those things.  As is typical with Van’s fiberglass, the fit is garbage.   Add my lack of skill to that, and the result is a set of ugly  fairings that just barely managed to get the job done.   I may wind up reworking the whole landing gear fairing mess, but for now, these will do.   I think if I actually make them smooth and trim off the excess, I’ll get a couple of knots out of them, but the process went like this:  Saturday – Fiddle with wet fiberglasss layups all day.   Sunday – trim the extra bits off, install some platenuts for mounting hardware, go flying.

That’s when I noticed the wing wobble.  running flat-out, with ground speed at around 190mph, trimmed up, the slightest bounce on the stick would cause a divergent oscillation..  This is without the autopilot, au naturel.   Bump the stick, the wiggle starts and just gets worse.    So I had to leave it for another week.

This week:

2 hours fiddling, almost 3 hours flying.  I can live with that.   First thing on the agenda was to double check the gear leg fairing alignment.   No issue there.   Next was clocking the governor back a couple of notches on the control shaft to get more RPM on my takeoff run.  It currently tops out at 2549, when it should be around 2600-2650.   One notch is too coarse of an adjustment; I wasn’t able to cycle the prop during runup, so I had to set it back to where it was.    With that fixed,  I went up just to confirm the oscillation, and sure enough, predictable and repeatable.   So I came back down and checked my rigging.  Turns out, one of the ailerons was off.   Not sure how that happened, but whatever it was, it wasn’t enough to cause a problem with the gear fairings and wheel pants off, at least not until the autopilot was engaged.   The AP couldn’t keep up with the oscillation either.    And, because I’d read about it, I checked the trailing edge of the ailerons.  The control surface is supposed to be absolutely flat from front to back, and then it wraps around where the trailing edge is bent.   This being a quickbuild kit, you’d think they’d be just fine.   Not so.  If the surfaces bulge outward at all, they can cause instability, so you do the heavy-wing treatment: Squeeze the trailing edges so the top and bottom are flat and not curved outward.   Even a little convex is OK.   But the idea is to go easy, not even enough to notice visually.

That was the magic bullet.    Hands-off, the stick stayed rock solid.   Repeating the bump test had the wings settle back to trimmed bank angle.   The autopilot was still a little twitchy though.   The fix for that was to move the AP control linkage to the innermost hole on the servo arm.  Less motion, more precise control increments in the stepper motor.   So that was awesome.   Being able to steer the plane with the heading bug is cool.

With everything trimmed up, balls to the wall, I managed to get 192mph ground speed in level flight.   The fuel burn was absolutely decadent, but it was pretty cool to go almost 200mph.   Oh, and the oil door stayed closed, which was nice.

So I did some more speed runs and spent some time getting familiar with the new handling.   A little different with gear fairings.   It doesn’t slow down as fast, for one thing.   I landed at SZP, went back to OXR, then spent some time in the pattern.   Landings are a little different as well.

Pants.

7 hours.

Put the pants on, one leg at a time.   I’m about to head back into my regular work schedule, which means days will become weeks.   So a task that will take a couple of days, will become a couple of weeks, because I’ll only get to it on weekends.  And the fun part coming up:  Wet fiberglass!  But this is what I got done today:

People’s exhibit A:  The right side wheel pant with the intersection fairings test-fit.

 

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Left wheel pant.IMG_1966

 

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Getting there.   Today was all about installing the mounting hardware for the fairings  Since we did the tweaky measuring stuff on Friday, today was all about just putting everything together.   Lots of platenuts to replace the clecoes from the position-locking drill ops.   But it is actually pretty cool how sturdy these things become once they’re put together and installed.   They’d better be.   They’re going to get the crap beat out of them.

Next is the wet work.   The intersection fairings will have to be taped on, then have a couple of layups of glass put on them to thicken them and make them conform to the exact shape of the fuse, gear leg fairings, and wheel pants.  I’m still working out the best way to do this, but I think it’s a two-day job.   One side per day.    Then the whole kerbang comes apart and I take the parts home and paint them.

Back to Project Status

IMG_19596 hours.

About 10 hours into Phase 1 testing, and so, time for the first oil change, among other things. Have I mentioned I love flying this airplane?   I’ve been flying all week and not blogging much, because I’ve been learning the airplane, how it flies, how it feels.  I can report with great accuracy that gyroscopic precession is a bitch:   If you try to lift the tail too fast, the aircraft will quickly be pointing at whatever is to the left of you.

I’m updating and rearranging the order of things in my checklists, based on where the task is spatially in the cockpit.   This is just good UX design, but like anything else, you work out the best workflows through usage.   For instance:  Put the flaps up before takeoff.   Yes, I know, this should be a post-landing task, and it usually is, but it doesn’t hurt to have it on the runup checklist before RPM to 1700.

The autopilot is more or less dialed in, but it still jitters a little bit.  This is unsettling and needs fixing, but that can happen later.  At least now it doesn’t pull a divergent oscillation in bank.   My fuel flow fix works as well.  I’m now reporting a burn rate consistent with what I expect for a given RPM or MAP.

Day before yesterday, I took a flight to Santa Paula to get fuel and spent a little time buzzing around the Ojai valley.  That’s where the above pic is from.   But following that flight, I decided to take a run at tweaking the idle, which is still al little rough down in the 750’s.  Last time I messed with it, I set it richer to cure the somewhat terrifying issue of it stumbling when advancing from idle to high RPM.   I think I went too far in that direction because since then, it’s run rough at idle and has been a bastard to start when hot.    The hot start is a known issue with FI engines, but even with the proper procedure, it’s difficult, so an adjustment had to be made.   This took the better part of an hour and a half, and the engine has to be hot when the adjustments are made.   This is why I have a nice burn on my hand from trying to get a wrench into the space where the idle adjustment arm is.   I’m still not ballsy enough to adjust this thing with the engine running.  That’s just not going to happen, especially when the exhaust pipes are still hot.   It’s amazing how fast ss exhaust pipes cool, but you don’t want to have a forearm laying on one when they’ve got hot gas blowing through them.

I was going to go fly again, but the wind put the kibosh on that idea:  14kts gusting to 20kts, although right down the runway.  I was too chicken to try to fly that, although I could have probably done wheel landings and i’d have been OK.  Better safe than filling out FAA forms over the wreckage of a balled-up airplane and a bunch of broken runway signage.

But yesterday saw the return of 313TD from aircraft to project.   David and I did the cutting and measuring of the wheel pants and gear fairings.  This is way more difficult than it has to be: You have to take the weight off the gear so you can align the wheel pants and gear fairings in trail.   Fortunately, the local airport mafia purchased a surplus forklift for a couple hundred bucks, and doubly fortunate, Dave knows how to drive one!

IMG_1960

I didn’t snap a lot of pics during the actual process because we got busy and stayed busy.   We first jacked up the plane on each side to install the wheel pant brackets, and took the opportunity to bevel the brake pads in an attempt to stop them from groaning during taxi.    Then we used the forklift to lift the airplane by the motor mount just high enough to get the weight off the wheels and the bend out of the gear legs.   Then there was a lot of crawling, measuring, and marking to find the centerline of the wheel parallel to the centerline of the aircraft.   We drilled the aft section to the gear brackets once we had everything lined up.

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It’s amazing how hard it is to find a 1″ block of wood in an airplane hangar, but 3/4″ PVC, no problem.  Short sections of that were used as spacers on the vertical to give the 1″ clearance required for the wheel pant.

Then we did the loop-of-string method to insure the gear leg fairings were in trail.   No drilling done there, but marking the position on the gear legs got us what we needed.

This whole process required making as much space in the hangar as possible, so we had to shove the Luscombe outside and move a bunch of stuff around to accommodate the forklift’s dance moves.

IMG_1961

The yellow chocks are where the forklift wound up to put the tine with a hole in it directly above the engine mount.

Of course, all this means that the aircraft is down until the fairings can be installed.    This is necessary anyway because I need to do an oil and filter change and a thorough under-cowl inspection.   Fortunately I can do some of the fairing work at home, like paint.   But what’s left is the onerous, fiddly part: glassing in the intersection fairings, then trimming and priming the pieces.   When that’s done, I should be able to bolt it back together and go flying some more.

[Untitled]

6 hours.

No, it’s never finished.   Today I took the seat wedges that Shelley made out to the hangar and installed them.  They boost my skinny arse up enough to see over the nose when taxiing, and put me in the same position I had when I finally figured out how to land Mike Seager’s RV-7.

I spent a bunch of time finessing the alarm and limit settings on the EFIS, then chatted with Jim D for a bit about his first flight, what to do, and what to expect.  Since I’d just set a bunch of things, I wanted to check it out, so I took the plane out for a little spin.

Everybody says “don’t do high speed taxi tests, they’re not necessary and they’re not worth the risk.”   I would normally agree with that sentiment, but I had a good reason: I wanted to make sure my prop wasn’t going to overspeed when I rammed it to the boards on takeoff.   I suppose I could have just pulled the prop pitch back if that had happened, but I really don’t want to deal with that in addition to everything else I’m going to be doing when I do the first flight.

I did a proper runup, because there’s no reason not to, and if the taxi test inadvertently became a first flight, it would be good if all the stuff works.   Called the tower, asked for a high speed taxi, waited for a 172 to land and get off the track, then I went.   RPM’s peaked out at about 2650, which is about right, so that’s good to go.  I braked  and got off at the first intersection, no problem.

After that, I got back into the EFIS and messed around with the moving map settings and autopilot setup.   Not that I’ll be screwing around with the autopilot or using the map a whole lot, but I did find out one important thing:  my autopilot servo was set to go the wrong way.   That means that if I turned the heading bug to the left, the autopilot would make the plane go to the right, which is really counterproductive.   So I fixed that.  Easy enough.

So now I just have to wait for a good day to fly it.

It’s go time.

7 hours.

313TD is now ready to fly.   It is legal, insured, fueled and ready.  If I didn’t have a mountain of work to do at work, I could go up there, push the airplane out into the open, fire it up, and take off.

It’s not finished.  Don’t get confused on that: Wheel pants and gear leg fairings still have to be done, and I’m still working out the engineering particulars on that one, because I have to suspend the aircraft in such a way that the weight is off the wheels to align the fairings.   Otherwise they act like little rudders, pointing the plane in an off-track direction.   This means you have to fight it with rudder input, and that means you lose efficiency because your airplane is essentially trying to fly sideways.

Efficiency is important.   Yesterday, I bought 22 gallons of aviation gasoline at $6.06 a gallon.  Ouch.   The reason for buying this gasoline is in preparation for the first flight, and also to calibrate the fuel level sensors in the wing tanks.   Each tank holds 21 gallons for a total of 42, so the plan was to do one tank at a time.

Our local Oxnard EAA chapter, which consists of the 8 guys who can reliably show up on the last saturday of every month and take care of business, has access to the really cool hand cranked fuel cart, which pumps both forwards and backwards and measures the amount of fuel pumped in either direction.

I called the Jet Center and had them put 22 gallons in the cart,  Which I could then use to increase the level in each tank according to the calibration “marks” on the EFIS.  If I recall correctly, these are 0.1, 4.6, 8.3, 12.5, 16.7, and 21.0 gallons.    The sensor is attached to a float inside the tank connected to a rheostat, and the numbers it puts out are simple resistance values read by the EFIS.   So with each amount pumped in, the settings menu gets the resistance value entered at that amount.   Simple.   I’m not sure how dead-on-balls accurate it is, but my initial test with the pump put 5 gallons into a 5 gallon gas can, so that was probably good enough.   I’m also not sure how much fuel it took to prime the pump and fill the filter chamber, but I’d put it at roughly half a gallon.   That’s OK, I drained about 2 and a half gallons from the aircraft tanks into a 5 gallon can before I started.

Also, this process needs to be done with the airplane in level attitude, because that’s when your fuel level actually matters.  Once again, Ron’s old lift was the solution for lifting the tailwheel.   The process was to pump 21 gallons into one of the tanks, set the levels, then pump it back into the fuel cart to verify the settings.    This also involved draining the current tank after the pump had sucked all the fuel out of the section where the fuel cap is, because even after pumping out all the fuel, there’s still 4 gallons left in the tank.   Also, when the pump runs dry, it still moves the counter.   Did I mention this thing is hand cranked? Yeah.  I’m sore.  Anyway, I repeated this process twice on each tank and the numbers were within .2 gallons each time, so the pump and the sensors appear to be doing the right thing.

So that’s done.   I’m ready to scramble.   All I need now is a day with good weather and relatively little outside stress, and we’re going up.

All Together Now

7 hours.

With the airworthiness inspection in the rear-view mirror, the next phase of this little adventure starts in earnest.   Of course, “airworthy” is kind of a misnomer.   It’s not airworthy until all the parts I took off for the inspection are back on.   That’s all the inspection panels, wing root fairings, floor panels, and interior.

When Dave and i measured the down angle of the flaps, we got one at 47 degrees and one at 49.   They’re supposed to be at 45, so that was first on my list to fix, but I measured them from the bottom side instead of the top and they both dialed out at 45.   Go figure.   After that, it was on to the interor panels.   I put the baggage bulkhead back in, flap actuator covers, then baggage carpet, bulkhead cover, and side panels.

After that it was the floor panels, with their multitudes of velcro discs designed to hold the carpet steady.   Then the front spar covers, and the tunnel cover.   This got interesting, because there are two holes in the firewall with platenuts that have nothing in them.   I can’t get the AN4 bolt in one of them and the other has a slightly off-center hole, so the bolt won’t seat in the threads of the platenut.   Bah.  Argh.   So I made the decision to put them in from the firewall side, which I’ll do later.

Then the fuel pump cover, with the newly attached fire extinguisher went in.   After that, I put in the carpeting, side panels, and stick boot covers.   It now looks like a proper airplane, and I could fly it, except for one thing:   The roll trim is wired backwards.

Yeah, I know, aren’t you supposed to be “ready for flight” when you call for the inspection?   Well, he didn’t make me fire up anything electrical, so I wouldn’t have caught this, because when I checked the trim motor, I saw the little arm on the trim servo move to the right when I toggled the right side of the 4-way on the stick.   Toggle the left side, the arm goes toward the left.   My brain failed to register that the arm is connected to wires attached to the bottom of the sticks, on the other end of the pivot point, so the arm is actually the reverse of the direction the sticks are moved in flight.

As soon as I realized this, all I could hear was Gunnery Sergeant Hartman in Full Metal Jacket:   “What side was that, Private Pyle?”

This, of course, is after I’d screwed down the fifty or so floor panel screws and installed the carpets and seating.   I figured it might be fun to sit in the airplane and get comfortable with the final UI of my airplane and practice things like getting the fire extinguisher out of its bracket, reaching fuses, finding the most comfortable rest spots for my elbow, that sort of thing.  So imagine my disappointment when I realized I’d have to pull the seat cushions, carpeting, and floor panels to switch the trim wires.

That’s a project for this weekend.   I also need to finish the cowl hinge pins, plug the aforementioned firewall holes, blob a little more RTV into the seams between the baffles and the engine, and do some taxi tests.   I know it taxis, I just want to see if I can get the under-cowl temps down a little more.

Even more legal, and some argh

10 hours.

Friday I got the static/transponder test done and that’s now in the logbook.   That took a bit, because I had to chase down some leaks.   And, somehow, I managed to snap off the hose barb that connects to the EFIS’s AOA pressure sensor.   That really, really sucks.   Now, once again, I have to dismount the EFIS and take it to MGL to have the AOA sensor replaced.  Can’t fix the barb.  The good news is that the AOA isn’t really necessary for first flight.   Also, my combination AOA/Pitot doesn’t lend itself well to the usual testing method of slipping a hose over the end of the pitot and hooking it up to the test machine.   But we worked around it by connecting the test line to the fitting where it connects to the pitot tube, so I’m going to assume it works.   We’ll find out.

Static tests eventually worked out OK, and we were able to calibrate using the EFIS’s setup menus.    All good!  Signed off, sticker in the airframe logbook.

Today was about picking up the pieces and extracting the EFIS backup battery for replacement.   I think it got run down too far too often and now it won’t take a charge and tops out at 6v.   To do that, I had to relocate the IO Extender module to someplace that would allow me to get to the screw securing the backup battery in its bracket.   When I had to move the IOX before to get it out of the way of the canopy, I’d put it on the end of a piece of angle behind the EFIS.  This solution was kind of half-assed, and I never actually felt good about it, so this is actually an improvement: I put it on top of the throttle quadrant bracket, up out of the way of everything.   I’ll have to dismount the transponder to make changes to the wiring, but that’s OK, it shouldn’t be necessary to change the wiring much.  It’s much more elegant, and gives me plenty of room behind the EFIS to do what I need to do, plus it’s more secure.

I did have to extend the power and ground wires for the IOX, but I was able to use the trim position wires as-is.  It also enabled a much neater wiring bundle instead of the slightly messy arrangement I had previously.

Outdoor fun.

5 hours.

I took my freshly painted spinner and cowl up to the airport to see how it would look. Not bad. Beats pink and purple, that’s for sure.

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Of course I forgot my hinge pins for the cowl, so I’ll have to bring them up next weekend.   But as part of the exercise of rolling the plane out to shoot these pics, i spent some time running the battery down, playing with the EFIS.   Also, Derek Spears stopped by in his Cardinal.    He gave me the quick tour of the GNS430, which is truly an amazing piece of hardware that I don’t know how to use just yet.  He walked me through the major modes and flight planning, and I was able to get the EFIS to pick up flight plans, nav info, and waypoints from the ARINC 429 feed from the 430.   Derek programmed in a flight from OXR to SMO using Van Nuys and Burbank as waypoints.  The EFIS displayed the legs as HITS boxes as well as a moving-map track.

Also, I confirmed that the nav antenna in the wingtip does work; I was able to pick up the Ventura VOR on 108.20 and feed the EFIS’s HSI with it.   One thing that bugs me a little;  In order to get VOR navigation stuff to show up on the EFIS screen, I need to be in External Nav Source mode, which means the EFIS doesn’t use its internal GPS.   This is ordinarily OK, but there have been issues driving autopilots using the 430 as a GPS source.   Something about the resolution and the frame rate that makes the autopilot hunt for headings, or something like that.

Also, of interest: The EFIS isn’t a big fan of low system voltage.   Piddling about with the equipment for as long as we did really ran the battery down, and when that happens, the EFIS does things like spontaneously reboot when changing screens.   This is not good.

So on  my to-do list is to sort out the backup battery and how to preserve EFIS functionality during all modes, including engine start.

Confirmed that the passenger headset jacks work, after fumbling with the audio panel for a bit.

After Derek left, I went flying in Don’s RV6A for an hour, then came back and did some more safety-wiring, and used my newly purchased Weld-On #4 to try to bond the small crack in my canopy.

I also set up the EFIS with all the V-speeds for the RV-7.