AZ Bearhawk – Page 7 – Our Building Log

Cowling!

My brother Timmy cam out again to help me tackle another large part of the plane. This time it’s the cowling. We spent several days working on this.

The largest part of the cowling is fitting and measuring!

Drilling the hinges for the doors was pretty easy. Yes, I was drilling over the carpet, but we cleaned up!

Trying to get everything lined up just right was a bit tough. So The method I came up with was to lay the door against the nose bowl. Then trace the edge of the nose bowl to the inside of the door.

Then we bought some masking tape that was exactly the width of the flange on the nose bowl. After putting the tape exactly on the line, I’d cut to the edge of the tape.

Worked perfectly!

Start of the cowling

We had to cut a hole to allow the carb through so we could position the cowling without interference. The manual says to take your time and cut the hole close. So we did.

Carb Studs

The carb studs weren’t out far enough so I had to unscrew them a bit.

They were awfully stuck! So we heated and removed them, then reset them to the proper position with locktite.

Propeller!!!!!

Look what’s in my front yard!!

We decided on the Hartzell Trailblazer Propeller. It’s an awesome prop!

So the next questions was, what diameter? Obviously, you want a big prop to help you get off the ground, but clearance is a consideration. There’s also the issue of supersonic tips at 2700 RPM. After talking with Mark Goldberg and the Hartzell reps, we decided on an 82″ prop.

I did some calculations, an 82” prop tip travels at 658 MPH @ 2,700 RPM. I’d have to get to 35,000 ft msl before the prop tips go supersonic. At sea level the speed of sound is 761 MPH. So, it looks like I’ve got a good margin.

My beautiful wife helped me hang the prop today!

And the real reason we’re hanging the prop now is to get the measurements for where the nose bowl will sit. Now that we have the spacing between the spinner and the nose bowl, we can start on the cowling!

Picture time!

Cati was nice enough to hold the brakes while we rolled our Bearhawk out for some pictures.

We didn’t have it in the driveway for 5 minutes before people started stopping by to ask questions!

Drilling Axels

Building an airplane includes a lot of little steps and very big steps. The big ones are easy to keep track of. Wings, engine, landing gear, etc. Those are hard to miss. However, all the small things could slip thought the cracks if you’re not organized.

So as I’ve gone along, I’ve made a list of things that need to done as I see/think about them. Drilling the gear axels was on that list, so today I drilled them for the big castle nut and cotter pins.

Ge Strut Reinforcements

I got the heavy duty round landing gear legs. These are new from Avipro. After production of these, Bob Barrows recommended welding reinforcements to the shock strut.

Mark Goldberg had precut and bent the strips for me, so all that was left to do was the welding.

Not too bad for a novice welder like me!

Access Covers

There are 4 access covers on the empennage that cover the stabilizer attachments. I couldn’t find any ready made ones that fit as I like, so I made them.