2024 - 2025 Fuel System Modifications

Engine overhaul
Electronics/Electrical
Fuel System
Trim System
Fabric Recover

Items #2 & #3 from the Rebuild page:  Inadequate fuel quantity.  A thirsty O-360 with only 20 gallons of fuel doesn't give a slow plane much range.  I want to work out a design to add some fuel to the upper center section.

Fuel quantity indicator.  It had a float and stick indicator like a Cub.  That's fine if it works, but on this plane, the float hit the back of the tank and the stick was not nearly deep enough to measure the lower half of the tank.  Not very useful if it only measures the top half of the tank.  I replaced that with a hydrostatic fuel gauge that measures the head pressure of the fuel.  That worked fine on the ground, but as soon as I start the engine, it would go full scaale to indicate full all the time.  So, now I'm changing to a float type fuel gauge.


12/18/2024 - Installed new fuel gauge in the panel.

New float type sending unit to go into the tank with Molex connector for wiring.

This is currently the only fuel tank in the plane.  It holds 20 gallons of fuel.  With an O-360, that's 10 gallons/hour at cruise in a plane that only cruises at roughly 100 kts.  With a 30 minute VFR reserve, that only gives me a 150 nautical mile range for planned fuel stops, which is very limiting.

I'll need to cut a hole in the top of the tank to install this unit.  I fabricated the clamping flange you see screwed on in the photo above to go inside the tank to allow me to clamp down onto the top.  I'll seal it with some ProSeal when it goes on.  The one small cad plated screw in the clamping plate is there to hold the plate up to the top of the tank while I insert the unit into the tank and run in the rest of the mounting screws.  This may require a second screw and nut plate when I install it.  We shall see...

1/4/2025 - The fuselage tank is now out where I can work on it on the table top.  The line on the side is where there is an internal edge at the bottom of the tank that I have to miss with the fuel probe, so I need to be in front of that line.  The line on the top of the tank (see below) is where the limit of where the back edge of the hold down strap will fit.  I've got a pretty tight spot to fit this all in.



This is what is left of the backing flange I made to go inside the tank to bolt the fuel probe into place.  The small phillips screw at the left holds the internal mounting flange up to the inside of the tank so I can run in the screws that clamp the probe down to the top of the tank.  Here's where I made a mistake that made things a bit more difficult.  When I cut this hole with my hole saw, I cut right into a vertical divider that runs down the middle of the tank.  Oops!  The divider is visible through the hole in the photo above.  That's why the hole all the way to the right is not drilled yet and I had to cut down the backing flange.  I cut the backing flange to butt up against the internal bulkhead.  Since there are two relatively thick layers of aluminum where the bulklhead buts against the top of the tank, I drilled and tapped the hole to the right through the tank and bulkhead and used that to hold down the fifth screw rather than a nut plate like the other 4 screws.

The backing flange is now mounted inside the tank with the countersunk screw holding it in place under the mark where I have "Index" marked on the top flange.  All but the one screw all the way to the right are run into nutplates that are riveted to the flange backing plate that is inside the tank.  The screw on the far right side of the flange is threaded into the top of the tank and the top of the internal baffle.  It is all sealed with a generous bead of ProSeal underneath and a finger fillet of proseal around the flange from where it squeezed out.

This photo is looking down through the filler neck.  You can see the fuel probe just missing the back of the tank and just missing the perforated bulkhead to the right.  The black slider at the bottom of the shaft is the float that floats up and down the shaft where it is sensed to indicate the fuel level.

1/7/2025 - The main fuel tank is now re-installed in the airframe.  That's the first part to go back onto the plane that had been removed, so is the first step towards reassembly.  Only about 100,000 steps left to go!  It is possible the bump on the top of the fuel probe may interfere with the top of teh boot cowl.  If I does, I'll cut an access hole and raise the cover 1/8" to allow it sufficient room.

The plan is to design and build an additional fuel tank into the upper center section, then refuel the lower tank from the upper tank by opening a valve to allow it to drain.  I hope to get 8 - 10 gallons into the upper tank, which would extend my range by an hour;100 nautical miles.  The volume will depend on how much room I can find in the center section.  It has cross braces that go through the middle of the center section, so I need to either move the cross braces and re-enforce the center section with plywood, or build some custom tanks to fit around the cross braces and plumb them together.  I'm leaning away from doing structural modifications to an aerobatic plane.  I'm not an engineer and don't feel that I'm qualified to analyse all the stresses the center section sees.  So, I'm leaning towards fabricating some custom shaped fuel cells around the cross braces and plumbing them together.  I'll start developing a more mature plan once I have the center section off on the bench and get the fabric off.

 
12/17/2024 - I found a drawing for the center section tanks.  I don't know that I'll build the tanks to plans, but this will be immensely helpful in designing the tanks.  I'm mulling over whether to build with Alumium and rivets, or Composite with a combination of Fiberglass and Carbon Fiber.

12/31/2024 - Last day of 2024...  I've got the center section off and am wrestling with the design for a fuel tank to fit into this space.  I think I've got it worked out in my head, so am mulling over getting supplies ordered to fabricate a tank to fit this space.  

Decision made; the new tank will be built from composite materials.

The Plan:  I plan to cut the two middle ribs out of the center section.  I'll add a plywood doubler to the other two remaining ribs along with substantial mounting blocks to tie them to the spars.  I will lay up a top and bottom for the tank using 1/4" core material and carbon fiber.  The top and bottom will overlap the ribs to the side and the spars front and back, then will also be tacked to the spars and ribs.  I plan to attach the bottom first, then build the sides into the tank, including bridging over top of the cross brace wires, with a piped pass through under the wires to ensure the tanks will completely drain to the back pickups.  I will also add two internal ribs to the tank to replace the ribs removed from the center section.  They will be attached to teh bottom, and will sit astradle the drag wires.  I'll then build bridge sections over top of the drag wires to seal them out of the tank.  Once the sides ribs and are built into the tank, I'll attach the top to the sides, and will also have the top overlap the ribs on the side and the front and rear spars as well as tacking them to the ribs and spars.  All resins used in the tank for composite work will be VinylEster and the interior of the tank will be prepped and painted with KBS tank sealer before installing the top.  Once the top is on, I'll add more KBS sealer to the tank and will slosh it around the top seam to ensure that the top seam on the tank is properly sealed.  


The first step is to create the top and bottom of the tank.  These boxes have the top and bottom of the rib form cut into them and will be lined with formica to create a mold for me to lay up the top and bottom of the fuel tank.  The parts will be created using a plyfoam technique with carbon fiber or fiberglass on either side of 1/4" divinylcell foam for a core.

1/2/2025 - Fabricating the wing tank top and bottom molds. The photo above is the mold to create the top of the wing tank.  The mold below is for the bottom.  I used some posterboard to copy the end rib of the center section and reproduced the same form cut into 1x4 pine for mold frames.  Then, I went to a local cabinet shop and bought some left over formica for $20 and cut to fit the frame.  Those are simple drywall screws holding the formica to the mold frame with epoxy resin also bonding the formica to the frame (and sealing the holes so they [hopefully] won't leak) when I vacuum bag the parts.  The drywall screws are countersunk into the formica and will leave obvious divits or bumps in the final part.  Bumps will get sanded smooth and divots will get filled and all of it will be under the fabric.  The two lines across the middle show where the existing ribs are in the center section and where I'll fabricate ribs inside the tank.The lines on the ends show where the end rib will be placed.  These are important landmarks for construction.  More on using these molds next week when I start laying up the parts into the molds.  



1/6/2025 - The mold is marked up and ready to lay up the top and bottom of the tank.  Thet stack of peel play is cut to fit the layups.  I plan to use peel ply on both sides of the layup so both sides will have a texture for bonding.  Fiberglass resin will need to bond on the inside and fabric and dope will need to bond to the outside.

The stack of carbon fiber cut to fit the top and bottom of the tanks.  The 1/4" divinylcell core material is also cut out and shaped as well, but not pictured.

1/7/2025 - The top of the fuel tank is laid up and now vacuum bagged.  I wish I could take pictures while I work, but I can't handle the phone while gloved up with vinylester resin on my gloves and I really can't take the time to take photos during the layup process.  However, this lay up stack from the mold up consists of 1 layer of dacron fabric that will be be peeled away, but is there to provide a texture to the final surface for the finish fabric that goes on the aircraft to stick to when this is all complete.  2 layups of carbon fiber, with the outside layer cut at a 30° angle and the second layer at a strait cut for a combined greater strength.  1/4" Divinylcell core material, as a sheer layer between the layups with the core perforated to maximize the adhesion to the glass resin.  The core material shows up quite clearly in the photo.  Over the core material are two more layups of carbon fiber with one cut straight and the other cut at a 30° angle.  Then another layer of dacron fabric (peel ply) that will act as a release agent that goes between the lay up and the absorbant batting, but also leaves a textured surface to attach other composite parts (the tank side walls).  Then there are two layers of absorbant batting to wick up any excess resin squeezed from the layup while under vacuum.  And finally covered with a single layer of Stretchelon 200 plastic to create the vacuum bag.  This is all being pumped down by a medical grade vacuum pump.  Working time for the vinylester is about an hour, so I had to work quickly, then get this all under vacuum so the atmospheric pressure could act to press it all together while the vinylester resin cures overnight.  You might note that this is winter time and the hangar temperature was down into the upper 30s last night.  So, that's a small heater that is placed just under the mold to keep it warm overnight while the resin cures.  I warmed the hangar with my kerosine heater before doing the lay up, but will use the small heater for localized heat while it cures..  Tomorrow I'll lay up the bottom of the tank using the same method.

1/8/2025 - Yesterday's part out of the vacuum bag.  This is the top for the tank.  Top side of it shown below.  Very stiff, and very light weight.



Now it's time to fabricate the bottom of the tank.  Different mold, but the exact same procedure as yesterday.  You can see this layup is a bit wetter than yesterday.  I used a bit more catalyst yesterday per directions for cold weather.  Things were setting up much faster than I would have preferred.  I used less catalyst today and just about 4 oz more resin, so the layup is much wetter and flows better.

Back to the center section itself.  I used my wood chisels to break out the mounts for the two middle ribs and removed the ribs.



This is how the top will fit onto it.  It needs a bit of cleanup and some trimming first.  Oh, and it needs a tank to cover.  Note that the top overlaps the spars and the ribs to either side.  The bottom of the tank will be fitted in the same manner.

I cut out 3/32" 5 ply aircraft grade birch plywood to use as doublers for the existing ribs.  That should stiffen them significantly to help support the tank sides.  One of the doublers straddles the drag wires from below and the opposing doubler straddles the wires from above.

1/9/2025 - Rib doublers glued into place.  We'll see how this sets up.  I used some T-88 that's left over from building my KR-2, so is roughly 30 years old.  It was quite viscus, but mixed well and was stiffening up very nicely.  I did reconstitute the T-88 by warming the bottles in some water on the stovetop last night until it flowed readily.

Layout for the ribs for the fuel tank.  Two of these will be internal ribs inside the fuel tank to replace the wooden ribs I removed from the center section.  The other two will be end ribs that will butt up against the ribs where I just added the doublers above.

You can see the outline of the ribs on the foam through two layups of glass, a layer of peel ply, the absorbant batting, and the plastic bag.  I keep this old section of formica countertop around just for doing flat layups.  It seems that I use it quite often.  The clear plastic used for this vacuum bag is from a roll of painters plastic.  Much cheaper and does the same thing as the expensive stretchelon bagging plastic.  While they sell some really nice sticky tape for sealing the vacuum bags, I have found that if I go to WalMart and buy the cheapest Latex Caulking I can find ($2.50 a tube) I can put it down liberally and stick almost any bag down to it and it seals beautifully.  In fact, I find that I have a lot fewer perimeter leaks and wrinkle leaks in the vacuum bags using caulking than I had when using the professional sealing dum-dum tapes.  Clean up is a snap as I just peel it off with a putty knife.  I also find garbarge bags to be very effective vacuum bags for some layups that require a complete bag.  Bag the whole part, poke a hole for the vaccum port, and seal the open end of the bag with caulking and you have a perfect vacuum bag with a good ability to stretch to form.

1/10/2025 - No work today.  We got about 8" of snow overnight and this morning.  I can't get out of the driveway, even with the 4x4 truck.  Back to it tomorrow (maybe)!


1/11/2025 - Today I laid up the front and back for the fuel tank.  

Remaining ribs with plywood doublers on them as they will help support the sides of the tank.  I'll also glue in substantial mounting blocks at the front and back of these ribs to bond them to the spars.  Side view of the same in the photo below.



1/11/2025 - Fitting the bottom of the tank.  It's not installed, but I've got it indexed and marked exactly where I want it.  I need to do the same with the top, then trim to fit.  Also, note the corner mounting blocks are in on the plywood ribs.  These bond the ribs to the spars front and back to support the ribs, which will be helping to support the tank.  They are bonded in with T-88 and also tacked to both the rib and the spars with T-88 coated 1 inch rib nails.

Back, front, internal and end ribs to go into the tank.  The dot pattern you see are perforations in the Divinylcell foam.  I have a porcupine roller that punches a bunch of holes in the foam.  I do this to both sides and this allows the resin to get a better bite into the foam core.  It is heavier, but substantially stronger than laying up the foam without the perforations.  This was done on all the core materials with both glass and carbon fiber.

This should be the last vacuum bagged part.  This is going to be cut up into several small misc. strips that will be used to bridge around the drag wires that cross inside the center section.

1/13/2025 - Things are taking shape.  Here you see the front and back (hidden) of the tank sitting almost in place, then the ribs sitting on top of the drag wires. The front and back pieces of the tank are now properly fitted, but are not in place in this photo as I removed the tank bottom to do a little bit of work on it.  I'll trim up the bottom tomorrow and have it ready to attach, then will start trimming and placing the ribs to get the tank pieces all fittted.  

1/14/2025 - After spending a week laying up various pieces and parts, today was the day to start fitting all the pieces together to build this tank.  Obviously, the cross braces running through the tank present a bit of a problem.  There are several ways to solve this problem, but my solution is to build the tank around them.  It is really tedious, but today I cut out and fitted the little pieces to bridge over the drag brace wires in the center section.  I am out of resin, so this is nothing more than a test fit.  I should have another gallon of resin arrive in the next day or two.


The ribs are just sitting in place, but this is how I plan to bridge over the cross braces in the center section.  The ribs, and then the bridge structures will all get floxed into place, then will get a layup of glass to ensure they don't move, then will be sealed with an additional coat of resin, then two coats of KBS tank sealer.  

All 4 side bridges standing in place and the walls to the center bridge in place.  Note, that I have not yet cut the various drain throughs into the two center ribs.  They will have areas to drain through between tank cells both top and bottom.  

I have just a blank piece of plyfoam sitting on top of the walls for the center bridge.  After I flox the center walls into place, I'll mark and cut the top of the center bridge (in an X pattern) to fit.  If I can construct all 5 sections and get them to seal successfully, this is how the interior of the tank will look.  Note the 3/8" tubes going through the 5 bridges to ensure that all 5 tanks sections will drain to the back.  I will install 4 pickup points into the tank (2 in the front and 2 in the back), and two fuel drains at the back of the tank, but at this point in time, only plan to use one pickup.  The engine will not be fed directly from this tank.  It will only be used as an auxillary tank to extend range for cross country flights and fuel will be drained from this tank to refill the main tank below.  Additionally, aerobatics will be prohibited with fuel in the center section tank.

The top is trimmed and sitting in place over top of all the internal structure.  Bonding this top on and getting the upper seams to seal is going to be the real trick to building this tank.  I've spent a sleepless night or two cogitating over this issue.  I have a plan that I am satisfied will work.  Once this tank is closed out, there is no getting it open again without doing some major surgery to the tank and destroying either the top or bottom of the tank.  I'll hang onto those molds for the top and bottom of the tank until I am certain this all works.  FWIW, this is not the first time I have built tanks from scratch using this method.  This is how the tanks in my KR were built, minus the cross brace wires in the middle of the tank.  Additionally, in the Cub section of this web site, you'll see where I used a very similar method to rebuild the damaged tanks in my SuperCub.

1/15/2025 - Bottom of the tank bonded on with West Epoxy mixed with flox, then nailed to the capstrip and re-inforced end ribs all the way around the perimeter of the tank using 3/4"  x .035" cement coated capstrip nails.

Front, back, end ribs, and center ribs are all now bonded into place.   The front & back walls of the tank, as well as the ribs are all bonded in using vinylester resin with flox.


1/16/2025- Lay up of glass cloth to reinforce and seal the ribs, front and back of the tank.  Same picture with the glass wet out with vyinylester resin below.



I bonded in the walls to bridge around the center section drag wires.  I'll reinforce them with glass tomorrow before putting on the tops.  Some might notice that I changed the center structure to a rectangle.  The previous crossbuck design looked like a weak spot to me, so I sacrificed a bit of tank capacity to ensure that I build a sound tank.

1/17/2025 - I bonded the tops onto the walls to build the tank around the drag brace wires.  I also bored through the bottom of the tank and installed welding flanges for 4 fuel pickups (one at each corner), and two fuel drains at the back of the tank.  I only intend to use a single fuel pickup for transferring fuel to the main tank, but will have 4 available if I see a need to modify it.

This glass cloth is there to reinforce the structure over the crossing drag wires.  Below, the same is all there with it now wet out, and a second layup of glass cloth tucked into the corners of the side braces and along the bottom of the cross brace structures and over the top corners of the structures as well.  I also wet out all of the tank bottom with vinylester to seal the carbon fiber and added a "plyfoam" doubler to the top of the ribs to give me a larger surface to use when I bond the top to the tank.  I will add a "plyfoam" doubler to the front and back as well.  Plyfoam - fiberglass or carbon fiber laminated to either side of divinylcell foam in this case.  Good stuff for building free form composite structures.



1/18/2025 - I bonded the doublers on the front and back walls of the tank to make for a larger mounting flange for the top.

This photo is the filler neck bonded into the top of the tank using vinylester and flox.  The top is on the bench upside down, so the top of the filler neck is pointing down in this photo.  The black mark on the filler neck is my index mark for pointing forward for the ram air pressure in the fuel cap.


1/19/25 - I painted the top with a coat of vinylester resin as a sealer.  I masked it and painted around the areas that will be used to bond the top to the tank.  17 degrees out and the wind blowing at 15G24 kts.  Brrr.  The hangar was 37º this morning even with a small space heater running to keep it from freezing, but the kerosene heater warmed it up into the 60's in about 15 minutes.

All the clamps are off and the interior of the tank has a coat of vinylester to seal it as best I can.  Do I think it would leak like this?  I would expect a few small seeps.  It is really difficult to seal every point in a tank like this with all the interior corners building over the drag brace wires.  However, the top and the interior of the tanks will be prepped and painted with two coats of KBS tank sealer, which will ensure there will be no pinholes or seeps.  I have used this stuff for many years and it is not your typical slosh compound.  It's really good stuff.  When applied properly, it won't peel or flake.  I get one shot at doing this, so it has to be right.  Once the top is on the tank, it will not be removable without doing significant damage to the tank.  

1/20/2025 - Prepped and painted the inside of the tank with KBS tank sealer.  Also did the same with the top for the tank below.  I'll apply one more coat, then leak test the tank before attaching the top.



1/25/2025 - time for a leak check.  The bottom of the tank is full of blue gold.  (100LL fuel)

Bad news.  It leaks.  I have done everything I can to build this, but I knew the cross buck design to bridge over the drag brace wires might be a problem.  Soooo.

I have no solution to fix this tank, so I ripped the whole thing out.  2 weeks of work and $1000 in supplies all in the trash.  This is repairing the original ribs re-installed into the center section.  I am just going to have to make due without an auxilary fuel tank as, right now, I don't see a good solution to add more fuel.  Dissappointing, but I don't get it right every time.

1/28/2025 - I've not completely given up on the idea of an auxilary tank.  I'm considering building a tank inside the baggage compartment shown above.  I would only use the bottom 8" of the baggage area, which would make an 8 gallon tank, leaving a small baggage area above the tank.  Additionally, I would add a bottom and back into the turtle deck (shown below), then hinge the headrest at the bottom for ready access, making for a second readily accessible baggage compartment.  I've not made a decision on this yet, but am mulling it over.

3/6/2025 - After weeks of doing engine work for others, I'm back to my plane again.  I have made the decision to have a local welder weld an aluminum tank for me.  Why?  There is a lot of uncertainty about the future of 100LL, and the G100UL candidate to replace 100LL is currently getting a lot of negative press regarding degredation of paints and composite parts.  With 10:1 pistons in the engine, this plane will require 100 Octane fuel.  So, to be on the safe side, I made the decision to build the aux tank with welded 5052 aluminum.  The first thing to do was to consult with the local welder.  We agreed to fabricate this using a bottom plate of .063" that will mount to the same tabs where the baggage compartment used to mount.  This bottom plate will become the mount for the tank.  The rest of the tank will be constructed using .040" 5052.  Interesting that I can order 2x3' sheets of 5052 on Amazon relatively inexpensively.
 
The baggage box is now out of the airframe.  Interesting that they had to bend it to get it into place, then rivet the back of the box in so it would retain it's shape.

This is where the baggage box used to be.  The aux fuel tank will get mounted into here.

I started to install that little cutout under the left side of the instrument panel as a place to mount a fuel gauge for the Aux Fuel Tank.  However, the carb heat cable was already kinked against a tube with it mounted to the right of the current fuel gauge.  With the little mini-panel under the left side, there was a second kink in the carb heat cable and that ruined the cable.  I had a new cable on the shelf, so moved the cable to the far left side of the panel to eliminate one sharp turn in the cable.  Then I did an offset grind on two washers on either side of the panel so I could mount the cable with the backside pointing downward a bit so I could eliminate the sharp curves in the cable.  It works better than ever now.

Next up was to fabricate a template for the floor of the new baggage compartment.  The way it fits, it will have to go in as two pieces.

I have the better part of a gallon of vinylester left over from the previous attempt at building a fuel tank, so decided to use it with carbon fiber to fabricate the floor and back of the baggage compartment.  VinylEster has a limited shelf life once it has been promoted to be sold, so this stuff needed to be used anyway as it will go bad before summer.  So, I had the vacuum pump running much of this week while I fabricated several small pieces from carbon fiber.

This is an example of how I do vacuum bagging if I am making flat parts.  I lay up the part on a piece of waxed formica countertop, add a piece of peel ply (dacron fabric), then some felt to absorb excess resin, then cover with plastic sheet cut from the cheap painters plastic drop cloth you can buy at Walmart.  Then I use the cheapest caulking I can find and run a bead of caulking around the part and slap the plastic down over it.  Plug in the inexpensive medical grade vacuum pump, let it cure and you have a vacuum bagged part.  Contoured or molded parts require some more expensive bagging materials, but if I'm making a flat panel, there is no need to waste my money on the expensive bagging materials.

This is the baggage compartment as fabricated.  You can see the seam of screws down the middle to hold the two halves of the bottom together.  They are also anchored together with some vinylester resin as well.  There is a black aluminum angle half way back in the baggage compartment.  I'll attach a baggage net to prevent larger or heavier things in the baggage copartment from migrating to the back of the compartment.  Think in terms of what might happen while going straight up in a hammer head.  Everything in the baggage is going to try to go to the back, then while coming straight down, it might very well come slamming forward into the front of the compartment.  I want to keep a bit better control of the stuff in there.

I peeled the upholstery of the old headrest off the aluminum plate it was mounted to and bonded it to a plywood panel.  That panel will be hinged at the bottom with a piano hinge to tip the headrest forward to access the baggage compartment.  Previously it was bolted in place.  I added a carbon fiber panel to the bottom of the headrest to close up the baggage compartment.  The headrest isn't mounted yet.  Only the piano hinge is mounted to the airframe.  The rest is just sitting in place to see how it looks.

This is the .063" 5052 aluminum base for the fuel tank.  I'll mount it into the airframe and on the mounting tabs for the old baggage compartment, then will build the rest of the tank onto this plate.  The rest of the tank will be .040" 5052 Aluminum.

3/8/2025 - I completed cutting out the pieces to fabricate the fuel tank.  It's held together with masking tape for now, but all the corners are tight enough that it shouldn't be a problem from the welder.  I have one welding flange with 1/8" NPT thread to go into the bottom of the tank to be the fuel drain.  I have another flange with 1/8" NPT that goes in the top towards the front that will be the tank overflow/vent, and another welding flange that goes towards the back of the tank on the top for the fuel pickup.  The big hole in the top is for the filler neck.  I don't have the fuel gauge transducer yet, so I ordered a gasket for it that I'll use for a pattern to mark the tank penetrations, then will rivet in the nut plates to mount the gauge.  The gauge won't be here until the end of the month, but once the nut plates are installed, I can take this tank to the welder to be completed.  

You can see in the photo above that there is a substantial flange around the bottom of the tank.  The tank will be mounted by that flange.  However, I will also add some padded steel angle under the tank to help support it.

Filler neck and two of the welding flanges.

Bonding the 3/8" fuel pickup tube into the bottom of a AN822-6D fitting that is screwed into the 1/4" NPT thread in the welding flange.

3/9/2025 - Added the USB charger outlet and electronics into the baggage bay.  I have an Echo UAT ADSB In and Out unit, and a Stratux ADSB receiver as a backup device.

The headrest is now attached to the piano hinge and closes off the baggage access when it's up.  I'll be adding a cabinet lock to it to make the baggage area lockable.