Category: Bearhawk 1175 Building Log

As part of my kit, I ordered the wood airfoils for the vertical and horizontal stabilizers.  I scuffed and cleaned the surface first, then epoxied the forms using T-88 epoxy.  After that, I sanded then coated them with Polybrush epoxy varnish.

This mod will give substantially more authority to the control surfaces while also reducing drag.  Because of the reduced drag, I can reduce the negative incidence of the horizontal stabilizers from -4 to -3 degrees.  This will further reduce the drag induced by the negative incidence.

This is a win win modification!

I decided on a 406/121.5 ELT with integrated GPS, antenna and battery by Kannad.  It’s the Kannad Integra AF.  It comes with a remote panel switch and it will source the ships GPS location as a backup.

Since 121.5 is no longer officially monitored, it’s a good idea to have a 406 ELT.  The 406 will send my GPS location via satellite with it’s specific identifier.  They’ll be able to look up my specific aircraft and pilot details along with phone numbers and names of people I specify.  Then when search and rescue gets there, they’ll be able to home in on the 121.5 signal.

Several people have mounted the external antenna inside the fuselage.  I decided to mount the antenna instead in accordance with the installation manual with the antenna external to the fuselage.  Since the part of the fuselage will be fabric, I’ll need to build a ground plane with copper tape.  Look for a future post on that.

I decided to build my electrical system around the Vertical Power VPX.  It’s an awesome system that simplifies wiring, provides exceptional reliability and allows substantially superior electrical system monitoring.

I started building a lot of the wiring harness and laying out the avionics tray.

After much consideration, I decided that I did want a beacon.  After substantially more consideration, I decided to place it on the belly, just aft of the main gear.  My reasoning was that since the beacons primary purpose will be for collision avoidance while on the ground, it is most visible on the belly since it’s a tail dragger.

I also finished fabrication of the boot cowl today.

Today we fabricated the rear bulkhead access door.  I saw this shape on a another BearHawk.  I thought it looked pretty nice so I copied it.

While I made the door, the girls spent some time deburring all the holes in other aluminum parts

I did the seat pan with PolyFiber.  Then applied PolyBrush.  I’m not sure if the PolyBrush was really required in this situation, but I read that some people wish they had done it.  So, I did.

I ordered the Confor Foam from Hi-Tech Foams.  I met the at Copperstate earlier in the year.  They were extremely helpful and helped me order exactly what I needed with cutting guides.

I attached the foam to the seat and to each other with 3M upholstery glue.  Then used a turkey carver to cut the foam.  The foam cuts much better when it’s cold. Luckily, Arizona was abnormally cold during these days!

Here are my little carvers showing their supposed strength and threatening to do some “additional” carving!

They turned out very nice.  I’m very pleased so far!

Since I’m using the Dynon pitot tube with AOA, I need to mount separate static ports.  I ordered these from Dynon.

I fabricated little mounts that will attach to the stringers after of the cargo bulkhead.

I had originally started cutting the door hinge slots in the right boot cowl side.  I didn’t like the fit so I decided to use pasteboard to make a new one.

I found this little contraption at Lowes.  It’s basically an upside down mounted jigsaw with a table.  Brilliant!

Doing it first in pasteboard makes is so much easier to get an exact fit!

I took quite a bit of time making exactly certain that I like how everything fit before drilling any holes.

Since the top has that removable panel designed to mount flush, I attached these reinforcing strips to the seems.  You can’t see it from this picture, but the far side is bent at a 90 degree angle to provide stability.

It’s starting to look more like an airplane!