Removable Belly Panels

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The plans called for a fabric encased belly which means that once the fabric is attached, I would have to cut it open to get inside the belly or tear out the complete interior and remove the floorboards to get at what I need to, which is an equally bad idea . . . and there’s no way I’m going to use inspection rings in the fabric because I’ll never place them exactly where they should be and they are just too small to ever get any work done.

Because it’s the belly, it’s an area that is likely to get a lot of abuse including water, dirt, stones, rocks and worse. I decided to divide the belly up into four removable panels with fixed sections between them. At each fuse tube crossover point I welded a pair of channels approximetely 10 inches apart.  These channels would be used to rivet fixed aluminum skins to.  In-between these fixed sections I would fabricate removable panels shaped with the same belly contour as the fixed sections. Using the rotisserie, I welded the channels and pre fitted the fixed skins.  The channels were actually “Z” channels that had an edge that would provide the removable belly panels a lip to fit up against.  The next question was, what material should I use to make the belly panels from. They have to be sturdy, light weight, follow the contour shape of the belly and be easily fastened.  On my next post I’ll describe what I used.

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Seaplane Preparation / Part 5 of 5

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The wings, tail surfaces, turtledeck, and fuselage were fabric covered at different times and each horizontal lower fabric covered  surface required the installation of drainage grommets. They are intended to drain away any water collected by condensation or otherwise from the lowest point in the airframe.  As an example, each pair of ribs in the wings has it’s own grommet on the bottom lowest portion of each rib bay.  An ordinary drainage grommet is the size of a quarter with a hole in it and is glued to the fabric.  Then you glue a larger diameter fabric dollie  over the grommet and then  take a soldering iron and burn a hole through both fabrics and through the hole of the grommet. If your going to put your aircraft on floats the Poly-Fiber Fabric Instructions advise you to use “Seaplane Grommets” which have a molded shroud that is open on one side.  These are mounted so the open hole or drain port points backwards thus avoiding the collection of water during take-offs and landings.

Another item unique for seaplane operations are flying dock ropes. These ropes are usually two to three feet long and hang below the leading edge of the wing tips. They help manipulate the seaplane while docking by providing a rope to grab and pull the seaplane to the dock. I reinforced the metal wing understructure and mounted 1/4 inch eyelets for the later attachment of the flying dock ropes.

The last and perhaps most costly item needed for seaplane preparation is a “Seaplane Prop”.  My 80 X 44 wood Sensenich will not survive the severe duty of water operations.  Water spray is like gravel and will quickly harm the soft wood surface. My hope is to use a Catto Composite 86 X 38 climb prop that is light weight with reinforced nickel edges .

Seaplane Preparation / Part 4 of 5

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Taking 13 years to build this airplane came with a price.

Have you heard of an AM/FM CD player, a VOR antenna, and a hydraulic pump to raise and lower the landing gear?  By the time I was done building the airplane all of these items were obsolete and replaced with something newer and better!  The tape deck was replaced with a tiny MP3 Player.  The VOR was replaced with GPS and the hydraulic pump was replaced with an electric motor system.  For seaplane preparation I made an extensive installation of a hydraulic pump, oil line network and electric plug and play set-up.  The hydraulic system is used to raise and lower the two main gear wheels and the castering forward gear.  I made the pump demountable so it would only be carried when floats were attached. The wiring harness and all the gear warning lights were all pre-wired with easy plug-ins.  All I needed were the floats.  As with the other afore-mentioned items I  became aware that my extensive accommodation for hydraulically operated floats was no longer needed.  The float company now uses an electrically driven motor system.  They did offer to buy back the pump if I purchase the new floats but how about all the oil lines and electrics I installed previously.  Oh well, I’m just too slow a builder to keep up with technology!

PS; The Clamar floats pictured above are on Larry Bauers seaplane and use the same hydraulic system as described above.

Seaplane Preparation / Part 3 of 5

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Other considerations needed beyond welding mounts and rudder retract tubes included attachment of the interconnect pulleys that connect the air rudder to the two water rudders. I purchased a set of EDO float installation drawings from Kenmore Air along with the specified pulley hardware. There’s a pulley on each side of the lower rear longerons and another balance pulley mounted between them on a crossover tube that completes the cable circuit. The brackets remained attached during the fabric skin assembly but the pulleys were removed and stored until needed for the later float installation.

Seaplane doors are basically gull wing doors that open up and away from the prop wash.  Additionally, it allows the pilot and/or passenger to quickly depart the cockpit to grab a rope or a dock.  A conventional side hinged door would be deflected by the prop wash making it difficult to open and quickly depart the cabin.

During the building process I had talked with other builders and seaplane pilots about the necessity of using a ventral fin for the float installation.  The fixed ventral fin fits on the rear underside of the fuse and adds to the overall rudder surface area giving the airplane more directional stability.  The problem is that not every pilot agrees and not every seaplane needs it.  I decided to cover my bases just in case and found  a ventral fin for sale in Canada.

In the early building stage it was difficult to think ahead of the day how I would actually raise the aircraft, remove the wheel gear and install the floats.  Luckily, the wing kit I built  had a very simple solution on how this would be done. It basically consists of a pair of “U” shaped metal fittings that fit over the wing spar bracket using the same through bolt. The top of the “U” has a welded shoulder nut that permits a large 3/8″ threaded eyebolt to attach to.  You only attach the eyebolts when their needed for lifting thus no need to fly around with them. Also this is the perfect place to lift the airplane since it is common with the center of gravity location of the complete airframe.