Trimmed Wheel Pant Mounting Shims

I popped the wheel pants off the plane, and all of the mounting shims turned out great.  There was plenty of squeeze out to ensure that the shims went to the edge of the mounting flanges.

I used my fiberglass cutoff wheel to remove the excess epoxy/flox and fair it into the surrounding glass.  I don’t care if this is perfectly smooth since it’s on the inside of the wheel pant.  I mainly just want to remove the sharp edges so I don’t cut myself when handling these in the future.  A lot of dirt and muck will get slung up into the wheel pants over time, so I want to make this reasonably easy to clean if necessary.  Finally, I reinstalled the wheel pants in preparation for final alignment.

Glassed Inside of Wheel Pants

I added a couple of layers of fiberglass to reinforce the areas around the mounting bracket attach points.  I then added some flox to the epoxy and spread a reasonably thick layer over the area where the bracket will sit.  A bunch will extrude out, but it’s easier to grind off the extra than mix up subsequent batches because there were voids in the shims.

I taped over the mounting flanges, then reinstalled the wheel pants so that the epoxy/flox could set up in the right position.

You can see the extra flox through the wheel pant here.  I didn’t want to use clecos to clamp this while the epoxy cures because that would flex the mounting bracket and squeeze out the excess epoxy/flox.  Instead, I simply used some really long 3/32″ rivets to keep the holes aligned.  I’ll put the plane back up on jacks and realign the wheel pants while opening these holes up for screws since there could be some misalignment introduced as the holes are drilled out.

Riveted Outer Wheel Pant Brackets

I scuffed up the flanges and epoxy/flox shims, then used some epoxy on the mounting surfaces when riveting these outer wheel pant brackets on.

Here’s the outside.  I threw a layer of glass over the outside to prevent the paint from cracking around the rivets.

Worked on Wheel Pants

I mixed up some epoxy/flox and glued the lower intersection fairings to the wheel pants.

After the epoxy cured, I trimmed the intersection fairings along the split line so I could fit the two halves together.  You can see that there are some gaps to fill.

The right side is much worse.  I’m going to have to build up the flanges since there’s such a large gap.

The wheel pants attach to the gear in three spots; the outer bracket shown here and an inner bracket that has forward and aft attach points.  Because the wheel pants are curved, the bracket flanges don’t conform nicely to the inside of the pant.  To fix this, I mixed up some epoxy/flox and applied some before clecoing the pant in place.  This will create a nice flat mounting pad for the bracket.  This bracket will be riveted to the pant and the others will get nut plates so the pant can be attached with screws.

I used some of the extra epoxy/flox to build up the upper side of the forward half of the lower intersection fairing.   I will need to sand away the other side of the fairing to align the front and back halves.

Aligned Gear Leg Fairings and Wheel Pants

I put the plane up on jacks and dropped a couple of plumb bobs along the center line.  I then snapped a chalk line on the floor so I can use it as a reference for aligning the gear leg fairings and wheel pants.

I created a second chalk line parallel to the aircraft centerline, but 38 5/8″ away which was roughly under the centerline of the wheel pant.  I then used a piece of scrap aluminum with a  square corner to measure up from the ground 8 5/8″ front and back to get the wheel pant parallel to the centerline of the airplane.  I blocked up the aft end with my chock to hold it there.  After aligning the wheel pant left to right (as shown in the next picture), I used one of my laser levels to mark where to drill (I aligned it with the hole with the front half of the wheel pant off and then reinstalled it).

The aft edge of the wheel pant needed to be pulled out a little bit to align with the centerline, so I used a ratcheting strap to the aircraft jack to pull it out until it aligned with the chalk line I snapped.  After everything was aligned, I drilled the holes through the inner fairing mount to lock in the position.

Before drilling the lower intersection fairings to the wheel pants, I needed to ensure the gear leg fairing is aligned.  I wrapped a piece of fishing line around the fairing and held it with a piece of blue tape.  I dropped a plumb bob down from the intersection of the fishing line and leading edge of the fairing and made a mark on the floor.  I measured out from the centerline and up to the fishing line so that I could make the fishing line exactly parallel to the aircraft centerline.

I transferred those measurements to a board that I positioned under the tail of the plane and then drilled a small hole at that position.  I ran the fishing line through the hole and tied it off to the tailwheel.

I slipped a small piece of static line over both lines and slid it close to the trailing edge of the fairing.  Amazingly, the left fairing was already perfect.  I had previously aligned it with the upper intersection fairing, but I didn’t expect it to come out this perfect.

With the gear leg fairing aligned, I could install the lower intersection fairings to lock in the angle.  I drilled the front and back halves with several 1/8″ holes each.

I then slid the upper intersection up tight and drilled a few holes to lock it into position.

Madeline was a big helper today, bringing me tools whenever I needed them.

I wrapped up the other side and then took the plane back off the jacks.  Although the jacks are very stable, we live in earthquake country and I didn’t feel comfortable leaving it up on the jacks overnight.

Test Install of Gear Leg Fairings

After grinding down some of the excess flox inside the gear leg fairings, I cut some slots for the hose clamp and installed the gear leg fairings on the airplane.  I’ll do a proper alignment with the longitudinal axis of the airplane later, but for now I used the upper intersection fairings to align these.

Here’s what the upper end of the fairing looks like.  You can see that I also drilled a hole forward of the slots to access the worm clamp’s adjustment screw.  All of this is hidden inside the upper intersection fairing once that is installed.

Dynamic Propeller Balancing and Fairings

Lee Apaka flew down this morning to balance the propellers for Greg and I.  Since I’m running at 2500 RPM with wide open throttle, we tied the plane back to the car and chocked the wheels.  Greg and I both have really smooth engines (a testament to how well Aerosport Power builds then), but they can always be better.  Greg started out at 0.35 IPS (inches per second), so Lee added 17g of weight (a bolt and some area washers) to the spinner backplate.  Amazingly, he nailed it on the first time and hit 0.02 IPS.  Anything under 0.1 IPS is pretty good, and 0.02 is somewhere between excellent and perfect.

After Greg wrapped up his run, I pulled my plane into position and Lee hooked up his gear.  I was only at 0.12 IPS when we started, so I was already a bit better.  We added 5.9g to my spinner backplate and ran it again. That dropped me to 0.11 IPS.  The formula wanted another 6+g mounted just a few inches away from the first weight.  Lee decided instead to add one more washer and a slightly longer bolt.  I did a third run and hit 0.02 IPS.  I’m super happy with the results.

Here’s where the weight was added to the spinner backplate.  There is a washer and an AN364 nut on the other side.  Our fix was to add one additional washer under the head shown here.

I jacked up the plane and started working on the gear leg fairings.I laid up some additional fiberglass inside and then mixed up some epoxy/flox mixture and gooped it around the line where the fairing will sit against the gear.  I then started working on the wheel pants.  With the fuselage level, I supported the rear of the fairing to get the center 8 5/8″ from the ground while simultaneously adjusting the fore/aft position so that the outer support bracket edge lines up with the step in the fairing.  I then drilled it to the outer fairing.

Worked on Gear Leg Fairings

I spent a couple of hours down at the hangar tonight, working on the gear leg fairings.  I bent the hinge pins and then spent some time installing them and removing them from the gear legs to make sure I could get the pins in and out fine.  I then drilled a hole in the top of the fairing so that the pin can be safety wire in place.

Restored Airplane to Flight Status

Since I had the aft baggage wall out to adjust the ADAHRS, I took the opportunity to inspect all of the elevator linkages and relubricate them.  I then vacuumed out the entire fuselage.  Despite doing this thoroughly before first flight, there was an amazing amount of debris including a large number of small metal particles from the drilling operation when assembling the fuselage.  I have no idea where these particles were hiding when I earlier cleaned out the fuselage.  I then reinstalled the aft baggage wall and all of the interior.

Before reinstalling the cowl, I adjusted the prop RPM again to hopefully get pretty close to 2700 RPM.  I also wrapped the fuel flow sensor with some extra thick fire sleeve and some safety wire.  It’s not the prettiest wrap job, but I’ll redo it if works.

Glassed Other Side of Gear Legs

No pictures tonight since it would look identical to last night, but I glassed the other side of the gear leg fairings.  I also stripped off the peel ply from last night and trimmed the excess epoxy.  I’ll need to sand down a few high spots before applying the filler.