The story of our Bearhawk started back in 2008, as an adventure with a family that hadn’t even been fully populated with its humans yet. It ended in August 2021, with, shall we say, liquidation. What follows is a long story that perhaps nobody else will read, but sometimes one finds that there is a…
Recent Posts
Bearhawk Pedal Planes
For our girls one of the highlights of going to Oshkosh was seeing the display booth for Aviation Products, the company that sells plans and kits for plywood pedal planes. These planes are usually set up to drive around, using a left-right stick input for steering. The fancy ones even have propellers that turn. During…
Avionics Cooling from the Fresh Air Vent
I’ve been having some GPS problems that I suspect might be related to the box getting hot. The first step was to install a vent in the boot cowl up above the stack, but that didn’t seem to help. After considering options like fans and extra exterior vents like Cessna did for a while, the…
Symptoms of Contamination in the Carburetor Float Bowl
Things were going well and running fine until I decided to take my friend James for a ride. He had never been in a small plane before, so he brought his daughter, who is about the same age as our oldest, and we took off for a sightseeing hop. After about 15 minutes, the engine…
Exchanging the Flightcom 403b Intercom for the PSEngineering PM3000
One of the complaints that I have had from the start with our airplane is the inadequate audio system. This is no surprise, since the audio system was one that I understood the least about, and it was the most difficult to integrate. Further complications came from our project coming with the Flightcom intercom already,…
Isolating 3.5mm Audio Jacks from the Airframe Ground
Back when I was first assembling our panel and wiring everything up, I had a hard time finding non-conductive shoulder washers for our two 3.5mm “earbud” size audio jacks. The big 1/4″ jacks had washers like these to isolate them from the airframe ground, but not the little guys. Well, this was a case of…
Replacing the OEM Dynon Thermocouple Connectors with Omega Connectors
All of my Dynon temperature probes worked well for about 100 hours. Then, I started getting intermittent readings on some of the EGTs. My research indicated that I might have been lucky to have not had problems sooner! Many builders have found that the Dynon-supplied connectors just aren’t up to the job, for a combination…
(not) Fixing The Broken Micro USB Port on a First Generation Stratus ADSB Reciever
I’ve enjoyed using the first-generation Stratus ADSB receiver to get in-flight ADSB inputs like METARs, TAFs, and radar returns. Life was going well until the day the female micro USB jack came out with the charging cord! It turns out this is a fairly common thing to have happen on these, and a subsequent redesign…
Symptoms of Losing the Idle Mixture Screw
We had some complicated plans for getting to Oshkosh Airventure 2014. The problem was that we had a wedding to go to in Boston on the Sunday before Oshkosh, and we had to be back at Oshkosh in time to set up the cookout on Tuesday. The plan we came up with was for me…
Using WordPress as a Building Log
Who doesn’t like WordPress? It’s fast, stable, and ubiquitous. I have used WordPress to power this building log, and it does a great job. There are so many folks using WordPress in so many ways that online help is abundant- which is part of why I’ll direct you to those sources for questions about how…
Flap Locks
As we prepared for our first trip to Oshkosh, we were concerned with preparing the airplane to live outside for a while. This involved making plugs for the air intakes, weather stripping the windows and doors, and coming up with a way to hold the flaps in the retracted position. Since the Bearhawk uses one-way…
An RV Builder’s Guide to Building a Bearhawk
I love the RV series of two-seat airplanes. They have revolutionized home-building, recreational flying, and perhaps even the overall world of GA. As far as airplanes go, they are pretty useful in that they go fast, handle well, and don’t have any bad flying habits. While they are useful as far as airplanes go, they…
Using the GoPro on the Bearhawk
I’ve always been fascinated with the
37 Hours – Oil Cooler
Here’s an update from about 37 hours since the first flight. I found a few hours ago that I was getting high oil temperatures. This turned out to be an indication of several minor factors that were working together. First, the ambient temperatures started rising with the arriving spring season. Second, I didn’t really come…
Mobile Phone-Controlled Preheat
Now that I’m flying with some regularity, I’ve found all sorts of inconveniences that are wanting solutions. Â One example is the engine pre-heat. Â This is a little bit of a princess complaint, since the airport is only a mile from my house. Â Still, I don’t want to have to get in the car, drive to…
Gross Weight Testing
Today I continued adding ballast to the Bearhawk to test how it performs at heavier weights. My ballast is 80 pound bags of concrete, so I started with 160 pounds in the back seat. The weight wasn’t really noticable during a few stalls and some phugoid tests. Since I was flying with close to half…
Russ Erb Visit
I had a long overnight in LAX today, so I checked in with Russ Erb. His schedule was available for me to stop by for a visit, so I rented a car and drove up to the desert. I was excited about getting to catch up with Russ and discuss a few flight testing strategies,…
Flying Update
I have found that the engine is running a little less smooth than I think it should. This is a challenging problem, in part because it may be running just fine. I have a fair amount of experience in single-engine piston airplanes, but most of it is not in recent times. At idle, I hear…
The Bootstrap Method of Performance Analysis
The first part of flight testing was relatively easy to plan. For the first few hours, I was just interested in getting the airplane safely into the air and back on the ground. I began to find the edges of the center part of the envelope in as incremental of a way as possible. After…
Transponder Check
Yesterday’s flights went very well, and after a second thorough inspection, the airplane still looked like it was ready to fly. I took off and climbed up above the airport again, and all was still well, so I flew over to the avionics shop to get the transponder checked. This will allow me to turn…
First Flight
Last week I drove down to Charlotte to pick up the airworthiness certificate. I got back into town with it just as a cold front did, and it took these 9 days to get a day with the right combination of me being in town and the weather being good. The weather was perfect all…
FAA Airworthiness Inspection
Today was the much-anticipated, rescheduled FAA inspection. I came out early to take off a few inspection panels and tie up the last few items. One was to add safety wire to the prop governor stop screw. Since I wasn’t sure that yesterday’s adjustment was going to be exactly correct, I hadn’t safetied it yesterday….
Weather Stripping
This morning I added some weather stripping to the cabin doors. I also installed small rivets on either side of the front window latches, as Eric Newton did. Hopefully these will keep the window from coming open on its own. I also endorsed the logbooks with all of the required endorsements. Now it’s just a…
Taxi Checks
Today was supposed to be the day of the airworthiness inspection, but the FSDO had to cancel it. I spent a few minutes working on a few minor things, such as installing the new Dynon backup battery that arrived, and replacing the GPS data card with a new database. I also adjusted the prop governor…
Compass Module Direction Swap
I’m back to working solo today. I started by making some extensions for the rear seat center seatbelts. I used 1/8″ 4130 to make little dog-bones, which would move the attach bolt outward by 1″. Then I cut a piece of tubing that was as long as the attach bracket in the seat structure. I…
More Odds and Ends
Today we worked more on the odds and ends. Dad installed seatbelts while I took the stainless tunnel under the boot cowl off. This part was vibrating when the engine ran, so I adhered a piece of 1/4″ thick closed-cell foam to try and dampen the vibrations. The rear seat belts have fairly large fittings…
Engine Adjustments
It has been really helpful having my dad in town to help with these final preparations. Today we drilled holes in the outboard aft corner of each fuel bay hatch. These holes will allow the fuel to drain more readily if the tanks begin to vent like they did yesterday. I also added the labels…
Filling the Fuel Tanks
This morning dad came out to help again, and we finished up the wing root fairings. I used pliobond to attach velcro to the fuselage tubes in the area where the back cabin bulkhead attaches. I noticed a very small oil leak around the prop governor control head, and a few days ago I ordered…
Final Tech Counselor Visit
Today my dad and I worked on shortening the list of final things to do. We started with installing the top wing root fairings, which I designed to use nuts. Nutplates would have made the work a one-person job, but since these will only come off when the wings come off, I figured that the…
Weighing
I’ve spent some time trying to come up with a good way to hold the airworthiness certificate and registration in place. The most light-weight option that I could come up with was to use pages from a small photo album. A trip to the Mighty Dollar yielded a little bunny book that I took two…
Fuel Flow Test and Engine Run
Much of the work lately has been sequential. I have a list of tasks that can’t really be done out of order. Today I was finally to the point on the list where it is was time to test the fuel flow. I did it in almost the same way that Eric Newton did, although…
Rigging the Ailerons
I started to set up the ailerons for their final rigging, and realized that when I routed the cables yesterday, the ends at the turnbuckles were twisted and not quite right. This made the cables about 1/2″ too long, but I was able to correct this by carefully removing the nicopress, shortening the cables, and…
MLG Width Adjustment
After a few days of work at my regular job, I was glad to get back to Bearhawk preparations. I installed batteries in the ELT and armed it. I set up to make the adjustments to the landing gear width as instructed by Bob. First, I tied a rope around the bottom of one axle,…
Main Landing Gear
I started today by adding a little bit of fuel to the tanks. I wanted to see if there were any leaks, and there were a few. I was able to stop the leaks by snugging up the nuts a little. One of the necessary adjustments is to set the width of the main landing…
Timing the Mags
With finally having all of the right tools in place, I was able to time the mags this afternoon. I started with the right. When I got to the left, I found that I didn’t really have enough adjustment. I could get the light on the timing box to change only when I was right…
Adding Oil to the Engine
While I wait for the new aileron cable to come in, I removed the old cables and used one of the front cables to make a replacement for the left rear. This will allow me to get the flaps on. Doing more things like this helps increase the odds that I’ll find unforeseen errors. Fortunately…
Final Wing Bolt Torque
Today an order came in from Aircraft Spruce. When I ordered the new aileron cable, I ordered 3/32″ diameter instead of 1/8″. This was a frustrating mistake, but fortunately they are going to accept a return on the 3/32″. I installed the wing tiedown rings at the top of the wing strut, which required removing…
Pitot Tube
This morning I finished with installing the pitot tube, and connected the AOA and pitot lines. I installed the VHF comm antennas in the top of the wings, and secured the wires for the right side wing rooth. I finally connected the front left upper fuel line at the wing root, since it needed a…
Installing the Wings
The timing of this whole relocation effort has worked out pretty well. Tonight was the EAA meeting, so we made it a project visit. Before the meeting, I spent a few minutes checking out the cowl clearance problem, and installing the rigid tube portion of the engine breather line. Lots of folks came out to…
Installing the Ailerons
Back at our first hangar, I loaded up the flaps, ailerons, wingtips, and a few other things to move to our second hangar. I unloaded those things and started making the connections that had been waiting on the wings. I connected the flap cables and fuel lines, excepting the front left fuel line, which wasn’t…
Moving the Wings
After the harrowing fuselage move, we left town for a few days of vacation. Now that we are back, it’s time to move the wings. These should be easier to move than the fuselage. The process included taking each wing off of the rack and putting them on saw horses. Then we put the rack…
Moving the Fuselage to HKY
Our little airport is going to be a great place to base our Bearhawk, in part because it is really close to the house. It’s a small airport though, and not really well suited for a safe first flight. As such, the plan has been to move the airplane to the municipal airport about 5…
Installing the Landing Light
The only trouble with those fancy firewall pass-throughs that I made yesterday is that it’s hard to install them this late in the process. If I had installed them back when the boot cowl was still off, I would have been able to do it by myself. Since that’s not the case, it’s a two-person…
Instrument Panel Labels
Since the roof and skylight materials are done, it’s time to get the windshield in place for good. I used the felt tape that came with the windshield to pad the bottom. The left and right post fairings worked pretty well, and the fiberglass fairing fits nicely. I used a bead of Lexel to try…
Doors and Locks
I made a little bit more progress this morning on the rubber seals for the front baffles. I decided to make an attachment for the horizontal portion of the front baffles that starts on the nosebowl, allowing the rubber to extend to the aluminum portion of the baffle and float freely there. So far I…
Pulling Off Tapes
This morning I stopped by to pull off the blue tapes and make sure that I didn’t have any problems to clear up. I had a few spots to clean up, but since the paint is so fresh, it was not entirely crosslinked and MEK wiped it off well.
Spraying Blue
This morning I finished the masking work on the cowling. With the cowling in place I found that I needed to trim my new extended front baffles just a little, so I did. I added the rubber seals onto the front of the side and rear baffles, and installed the new 45-degree breather fitting that…
Stripes on the Cowl
At this stage of the building process I’m tying up lots of loose ends and checking things off of the to-do list. I started by making a length of coax that will go where I had intended to put the balun in the previous antenna arrangement. I mounted the cabin heat box in the hole…
More Baffling Accessories
Today I started by finishing the front baffle work. I installed the flange for the blast tube that will help cool the alternator. Next I reconnected the oil pressure wire and started to install the breather tube at the engine. The fitting that Bob supplied for this purpose routes the hose too close to the…
Removing Tapes
Today I made a quick visit to remove the masking tapes from the door and window frames. I wanted to be sure that there weren’t any other peeling problems with those parts, and to minimize the time that the masking tape and papers were on the polycarbonate. Everything looks good.
Painting the Last White
Before painting time I worked on two dangling firewall forward tasks. The firs twas to make a support for the tailpipe where it passes under the firewall. This is totally made up by me, so it may not work. I started with a few inches of angle aluminum. Two holes are matched to the holes…
Preparing for White Paint
The primed parts are still in the booth from the last session, but I have a few that are due for white paint but not primer. Today I prepped those so that I’ll be ready to paint in one batch. These parts included the front door and window assemblies that peeled due to inadequate abrasion…
Last Round of Primer
Today was a long run to get the last round of parts into the paint booth for priming. I say the last round, but I actually mean the last round before the first flight. There are still a few bonus parts like fairings that we’ll paint later, after the plane is flying. I started with…
Nose Light
The cowl work continues. I drilled holes for attaching the new fiberglass bump. I installed yesterday’s nose bowl backing strips with a little bit of JB weld to hold them when the screws are out. I returned to the nose light bracket. I made a lens out of spare window polycarbonate, but didn’t like how…
Cowl Fasteners
Update from the Future: April 2018- It seems that I probably should have put a fastener on the vertical section of the cowl door also, not just the horizontal section below. Here is more detail: https://bearhawk.tips/3308 To update the parts list, the wing camlock studs are 2600-3w along the bottom, and 2600-5w going through the…
Cowl Reinforcements
In some areas of the cowl, the exhaust clearance holes have caused some pretty narrow sections. I can see that those might be potential crack areas, so I made some doublers to help them out. The first is for the area between the scoop and the exhaust tailpipe. The second is between the scoop and…
Fiberglass Surface Work
Tonight I sanded the filler that I applied yesterday to the new fiberglass cowl bump and the windshield fairing. The windshield fairing is ready to go, and the bump only needs a little bit more. The amount of work required to finish the bump was much less than on previous parts. I would definitely recommend…
Cowl Work Continued
This morning I made it to the hangar well before sunrise. It’s a nice time to work, on occasions when I would not rather be sleeping. I removed yesterday’s fiberglass handiwork and started with the finishing process. I used the belt sander to trim the edges clean, and applied the first round of filler. While…
Fiberglass Bubble
This morning the foam was well-cured so I did a bit more shaping. I covered the foam with masking tape so that the final fiberglass part will not show where the voids are in the foam. Another option would have been to fill the voids with filler, but since this is a small part and…
Preparing for Fiberglass
The exhaust clearance problem is going to require a little bit of fiberglass work. My strategy is to build up some foam on the pipes so that I’ll have a safe gap, then lay the fiberglass up right on that foam. To help make sure that the gap is a consistent 3/4″, I made up…
Visit with David Bice
Today was a real treat- I was able to visit with David Bice while on a visit to ABQ. David’s Bearhawk is of particular interest to me because it is so similar to mine. I even used the same paint colors as he did! His has an angle-valve 360 with slightly lower compression than ours,…
Skylight and Cowling
I had some help today from Tabitha and her dad. They started making the plates that will go on either side of the new VHF nav antenna. These plates are basically the same as round inspection covers, except that they have a slot in the middle to clear the antenna puck. While they did that,…
Installing the Exhaust
On the day that I was planning to leave to drive to Oshkosh, we got a huge amount of rain, and part of our driveway washed away. We had a big mess in the yard and lots of things to clean up, so I’ve lost a few weeks worth of building time. Today I was…
Boot Cowl Rivets Continued
I’ve noticed that the control sticks have a little bit of play around the fore-aft aligned bolts that they pivot on. I thought it would be worth trying to correct this, and after considering several options, the most viable seemed to be to enlarge the hole slightly and use a specially-made bolt of a larger…
Horizontal Stab Fairings
Tabitha and Felicia came out to help today. We installed the new tubing in the sight gauges and reinstalled them. We deburred the previously-made wing root fairing for the right wing. The girls went home for supper while I stayed to make the root fairings for the horizontal stabilizer. They attach to the inboard rib…
Boot Cowl Riveting
Yesterday’s black paint was dry, so I riveted on the windshield support angles. I reinstalled the now complete boot cowl pieces and riveted the front. Since those front rivets are through the firewall flange, they are very easy to get to for squeezing. The back rivets are a little bit more difficult, so I’ll do…
Left Wingtip Fitting
Today I finished fitting the left wing tip. That involved installing the strobe power supply and the left aileron, then drilling with the hole duplicator strap. I countersunk the holes, which will also have special countersunk washers to help distribute the load on the relatively vulnerable fiberglass. I also sprayed flat black paint on the…
Fuel Tank Prep Continued
I needed to finish up a few more jobs before I could put the left tank back in. One was to install the Dynon OAT probe and reconnect the wires. Another was to get the end of the antenna lead sorted out. I have plans to mount an antenna on the left wing that will…
Clean and Reinstall Left Tank
This morning I set the tension on the elevator turnbuckles to 30 pounds and safety wired the buckles with the double-wrap method. I made some aluminum strips that will attach to the perimeter of the hole in the back of the cabin, which will give me a better surface to attach velcro to for the…
Reinstalling the Tail Pieces
Today was a fantastic productive day in the hangar. I started by applying a little bit of superfil to yesterday’s wingtip extension. That is really some great stuff. The jig holes in the nose ribs on the left wing were 1/4 inch. This was just enough room for the AOA lines to fit through the…
Wing Rotisserie Removal
Today I started early in the morning by rearranging things in the hangar. I made a pair of large saw horses to support one of my temporary work tables, which will free up the plastic factory-made saw horses for paint booth duty, and more immediately, support the left wing. With the rotisserie parts out of…
Striping for Blue
Since the boot cowl parts and door parts have their white paint in place, today I started laying out the stripes for the blue coat. In the case of the upper front windows, they didn’t get any white, since they will be all blue. I also started working on a mount for the pitot tube,…
Reassembling the Front Seats
This afternoon I reassembled the front seats, and changed the routing of the transponder antenna feed. When I was routing it last time, I had forgotten that I’d already drilled a hole for the antenna, which the old routing didn’t reach.
Visit Mike Bundy
Today I was in southern California for a little while, so I contacted fellow Bearhawk builder Mike Bundy. Mike spent most of the afternoon with me, including transportation from the hotel I was in. He’s a very nice fellow, and has an especially interesting engine for his Bearhawk. He’s using the 409 cubic inch 4-cylinder…
Nutplates and White Paint
Several days ago I ran out of number 6 nutplates, so I ordered more. They arrived today, and I spent a while dimpling their lugs and installing them on various parts, including the belly sheet metal, the boot cowl, and the wing root. I riveted together the inspection covers that I had previously disassembled for…
Door Assembly
Yesterday’s painting included several door parts, so today I riveted the front cargo door together. I prepared the lower front doors and rear cargo door for their exterior white paint, with the interior paint already having been applied.
Painting White
Today I sprayed white paint on the parts that I primed a week ago. I added to that pile the rear cargo door, front cargo door parts, and other window parts.
Pieces to Bend
I thought of a few more pieces to bend, and I’m planning to make a visit to another bending brake soon. I stopped by today to cut them out.
Priming Wingtips and More
Today I prepared for a big round of priming, which meant more fabrication on boot cowl parts. I drilled for nutplates, which I’ll rivet on after priming. I made a support ring for the rubber gasket that will seal the shock strut. On the left side, I extended that support forward several inches. This hatch…
Nutplates and Wingtips
Today I worked on the wingtips yet again. I have really made the whole wingtip process much harder than it needed to be. I added the nutplates back for overlap mounting, and reinstalled the strobe power supplies. I also added a bit of window screen to the lightening holes in the tip rib. I also…
Final Boot Cowl Continued
This morning I started by drilling the holes in the lower boot cowl and belly panels to final size. I cut out some new aluminum for the roof, and the strips that will retain the left rear window. I drilled the holes in the firewall station of the boot cowl (and the firewall flange) to…
Roof and Boot Cowl
I started off today by finishing the bend that I started yesterday. I only bent the roof piece to about 90 degrees on the brake, because that was all it would do. This morning I used the dead blow hammer to bend it the rest of the way over. Unfortunately, it’s too short. When I…
Bending the Roof
Today was a quick stop by the airport in Lincolnton to borrow a friends bending brake. I bent the roof piece over to about 90 degrees on the way back from work. There was a bit of confusion initially, as my mechanic friend wasn’t there. His boss was, and when I confirmed that it would…
Finishing the Exhaust Mockup
Today I finished the PVC version of the exhaust and sent it off. Now I’ll be able to get back to all of the other stuff that needs to be done.
Exhaust System Mockup
Today I was finally able to start on the exhaust system mock up. As you can see in much earlier entries, I started with making an exhaust system out of EMT conduit, like Bob and others have. I wasn’t too pleased with how it was turning out, and I was especially concerned about excess noise…
Fairlead Pliers
I started re-installing the control cables today, and after a little bit of trying it became obvious that I was going to need to be able to get the fairlead clips on with the limited access that I had in the fuselage. I came up with the idea of modifying my snap ring pliers so…
Making Windows
Today I continued work on the lower right door, and assembled the frame to the skin with the Makrolon in between. I cut out the blanks for the skylights and drilled holes in those pieces. I mentioned last time that I needed to get another bolt for the carb/airbox attachment, and today I brought the…
Straggling Wires
Today was a day of rounding up loose ends. I finished bundling the wires aft of the firewall, and made a few more connections forward of the firewall. I installed the weather pack connector in the landing light wires that will allow for easier removal of the cowl. I also connected the oil pressure wire….
Bundling and Securing
I’ve done enough wire tying today to make the sides of my index fingers sore. I started with adding cotter pins to the brake cylinders in the cabin. Then I installed back shells on the instrument panel connectors that didn’t already have them. I added a few more nutplates to the boot cowl area. I…
Engine Installation Again
I picked up where I left off yesterday by continuing with engine preparations. I added safety wire to the bottom of the baffles, to hold the front and back curved sections inward. I also added safety wire to the oil filter, tachometer drive cap, and oil pressure relief valve. Then I reinstalled the engine and…
Engine Preparations
As I prepare to put the engine on for what will hopefully be the last time before we fly, I took advantage of the easy access of having it on the lift to finish up a few jobs. One was to install the oil line that will run from the prop governor to the fitting…
Brake Lines and Blue Paint
Today was a marathon day in the hangar that spanned from 8:15am to 2:00am, with a break for lunch of course. Here’s a nice overview picture of the parts hanging from the ceiling, each protected from dust and over spray by a sheet of clear plastic. I started working on the inspection covers for the…
Preparing to Spray Blue
I spent a little while today getting ready to paint the blue portions of the left wing. I taped the rest of the white areas and it is ready to go.
ANR Headset Jacks
I’m glad to be back in town for a few days and am looking forward to lots of hours in the hangar. Today was a good start. I started taping the left wing for the upcoming blue paint. I also installed LEMO ANR headset jacks on the panel, since they came in from Bose. I…
Final Wiring
Today was a short day, but I was only in town for a little while. I had to order more wire to use for the aft SAE jack and the landing light, and since those wires arrived while I was gone, I started routing them today. There are only a handful of wires left to…
Painting White on the Left Wing
Today was a good painting day, so that’s what I did. I was able to get the white paint on the left wing and flap.
Masking the Left Wing
I had a long weekend break and was able to get home for a few days. Tabitha came over to help install the inspection hole covers on the right wing. I measured the right wing’s tip and root sections so that I could transfer marks onto the left wing tip and root. Then I connected…
Visiting Graham Meise
I was in Orlando for a while this April and May to learn a new airplane at work, and while I was there I had a chance to catch up with Graham Meise at the KISM airport. Graham has a 4-place Bearhawk kit and he’s jut now starting to have time to work on it….
Priming the Left Wing
Yesterday’s high humidity complicated my painting plans, but I have to leave town for a while and wanted to get the wing primed before I left. This morning I got it all done in about 2 hours, which is much less time than it took me to prime the other wing.
Fuselage Plumbing
I was getting ready to prime the wing today, but it started raining. Instead I started routing the static line from the back of the fuselage up to the instrument panel. I also reinstalled the rest of the cabin fuel lines. I had originally planned to route the wires for the manifold pressure sender through…