Today I finished the aluminum belly piece, at least for now. I wanted to further test my wingtip strip technique, so I put in a few rivets.
I'm using the -4 rivets to fill the holes from the first round of wingtip screws, and the -3 rivets to fill the holes from the old rivets.
Here's the results of an order from the Yard, thanks to a little Christmas money.
Today Tabitha came out and started working on her toolbox practice kit. The weather was nice, so we opened up the hangar door and let some sunshine in. I made more progress on drilling out the rivets that held on the nutplates for the wingtip screws, and started making the first strip for the wingtip support.
Tabitha Squeezes Rivets
This is the Flush Mount Wingtip Support. Note the 1/4\
I used the snips to cut into the 1/4″ hole, leaving the original hole as the inside of the new “V.”
Each cutout matches a rib flute. I had to give the strip a little bit of a bend so that it would fit the airfoil shape more naturally.
The wingtip support strip also makes a nice set of teeth.
Today I finally got a nice middle joining angle for the two belly pieces, on the 4th attempt. It looks fine now. I spent the rest of the time drilling out rivets on the wingtip.
I really thought that attempt number 3 was going to be a good one, but I drilled the holes too close to the edge.
Note that the edge distance is way too short on the bottom strip.
This joining piece is more complicated than a joggle, but I think it will help give the entire panel some good stiffness.
I drilled, deburred, and dimpled the holes, and now it's time to squeeze a few rivets.
Squeezing Rivets!
If I were starting with a fresh kit, I would have probably just planned to mount the wingtips by overlapping them above the wing skin. In this case, the holes in the fiberglass aren’t quite as I would like to have them. The end result is a little bit of waviness between the screws. There isn’t anything wrong with this really, in fact it is how lots of other airplanes look. But, since I’d like to try and smooth out the waves, I’m going to do it differently. Since the holes in the fiberglass are just slightly off, it would be quite difficult to attempt to drill new holes right next to them. To solve this dilemma, I’ve decided to mount the wingtips so that the fiberglass butts up against the wing skin, with a little support strip underneath.
Here are a few holes after I've drilled the rivets out.
After drilling out a few rivets, it starts to get to be pretty easy.
I only had half an hour to work today, but I made up another aluminum attach/stiffener for the belly panels to join with. When I drilled the holes, it turns out that the angle piece wasn’t wide enough, and thus the edge distance from the rivets was way too small. See pictures in the next entry.
Today I worked on installing the left side belly panel. It is the same as yesterday’s entry, but just on the other side of the airplane.
Here is the left side still as a blank.
Here's a picture of me trimming the part.
Here's my first attempt at a piece to use for joining the two panels together. It is way too skinny!
Today I was working on the new aluminum piece that goes on the belly just aft of the exhaust tunnel. I decided to remake these pieces because of some mismatched holes, and so that I could make the panel in two pieces. By making the left and right halves separate, I feel like I can have a closer fit around the landing gear shock struts, and I can add a dual-purpose aluminum angle joining and stiffening piece in the middle.
I started out by using the old one-piece belly section as a guide. I used .025 2024T3 stock to cut the flat blanks, then slowly started adding in the various perimeter shapes. I bent the very slight bend on my toy bench top brake, and then cut and trim to make the fit just right. Here are some pictures of the part clecoed in place.
Here is a view of the right side panel from above. The floorboards are out in this picture.
Here is another view from above, including the new aluminum side piece, which joins to this belly piece.
This picture is looking up from the left side.
Here is the mostly finished part. It still lacks a joining tab aft of the landing gear hole, and hasn't been dimpled yet. I've been holding off on dimpling any of the boot cowl parts, since I'm still not entirely sure about how all of that is going to go together.
Here I am deburring the aluminum panel that goes on the right side.
I wanted to get in a little more welding practice and I needed to make a gift for our dirty santa gift exchange, so I made this guy out of some scrap materials:
Evil Creature
Welding the other side of the fuselage went much faster, and it turned out better.
New Steel Support in Place
I used a little rattle-can primer to keep the metal from rusting. I’ll replace that with some epoxy primer when the weather warms up, so that I can be sure that the covering process won’t lift the paint.
I decided that I didn’t like the idea of using aluminum angle as the aft support for the panel that goes under the door. This was mostly because I couldn’t think of a way to attach the aluminum angle very cleanly, so I figured I’d try to make one out of steel. I would be able to weld the steel to the fuselage, making for a much cleaner attachment. I saw that Bob specified .032 mild steel for the bulkhead at the trailing edge of the boot cowl, so I used .030 for this piece. It took me a little while to get it cut to shape and to bend it on my little toy brake, but I was very pleasesd with the finished product. I bent the trailing edge also, partly to increase the strength of the part and partly to be sure that it doesn’t chafe the fabric.
Aluminum Angle on top, steel blank ready to bend.
Aluminum Angle on top, steel blank ready to bend.
I made a paper template of the flat piece before I bent it.
I was a little bit worried about welding on the longeron. Making hangar doors is one thing, but welding on an expensive fuselage is another. I had a scrap piece of 3/4″ .049 (Bob’s T11) tubing like that of the longeron, so I started practicing. Since the tube is .049 and the tab is .030, it took a little practice to learn how to keep the heat off of the thinner piece. You can see the result.
Here you can see that the longeron sample tube is .049" thick compared to the .030 tab. I wanted to practice dealing with this difference.
It looks pretty good in the middle, but the ends need work.
This is a bad one. I started using narrower pieces just to make it harder.
Here is the end after trimming and ready to fit. Note the clearance for getting the floorboard in and out later
Here you can see the cleco side clamp holding the bottom ready for tacking.
Here is the left side in place
Here is the left side in place
I used a 90 degree die grinder with a scotchbrite pad to remove the paint on the longeron and door sill, which was quite effective. In the end I was pleased with the welding, and now I just have to make the other side.
Here is the inside view of the panel.
I had a surprise morning off from work due to some cancellations, so I spent a couple of hours working on a trailing edge support for the optional aluminum panel that goes under the door. I like the idea of using this panel for two main reasons. One is to make for a place to attach the lower strut fairing. The other is to protect the fabric in a high-traffic area. I didn’t really think of a good way to mount the aluminum angle support that the avipro manual describes. Some other builders have been able to figure out good ways to do it, so I picked up some 3/4″ angle and started working on making a piece.
Here is a mark so that I can trim the panel to match the other one next time I have it off.
Here I am working on it again.
Here is the end of the Aluminum angle. I tapered it some to try and limit the bulge on the longeron. The current shape still needs one more cut to allow the floorboard to be removed later.
Here is the angle rear support stuck in place. I sort of missed when I cut the slot for the tube. I don't really like it.
This is a view looking up from the bottom. The tunnel is on the left, and the aluminum belly piece is on the right. I'd like to bend the aluminum piece a little bit differently so that it lines up with the tunnel at the trailing edge.
I wanted to work on something other than the boot cowl for a little while, so I put together one of the door latches. I’m planning to use Bob’s design for the latch and will add some locks. I found some very compact cylinders at Home Depot for under $5 each. I got 3 that were keyed the same, just because I will probably not be able to buy more with that same lock again. Who knows, I might even use all of them. I also started looking at the optional aluminum panel under the door to see how that should go together.
Today I made a trip up to Fincastle to Bob’s. We’re going to be taking over the Bearhawk logo shirts and hats and the trip was to pick up Bill’s inventory. While I was there I asked Bob a few questions and took some pictures of his airplanes.
Bob's hard brake line attached to caliper. I asked him about this and he said that a flex hose of some type might be better.
Here's the top of Bob's instrument panel. I was wondering about how he addressed the sharp edge that the top piece makes if you let it overhang.
I took this picture so I could put the ends on the tail struts, which I'm going to have to make.
Here's the top end of the strut
This picture is to document the location of the latch that holds the window open
This picture is to document Bob's rivet spacing on the wing tip.
These pictures are for documenting the access panels in the tail.
Here Bob is assembling the crankcase halves on a 360, not unlike ours.
Lycoming 360 Crankcase Half
Bob just recently added this wing strut fairing to his Patrol. He said that he could see the skin vibrating just aft of the attach point because of the turbulence.
Here is the front view of the faring. Bob made it by forming a modeling clay shape on the airplane and then adding fiberglass around that.
After the fiberglass was cured he removed the modeling clay.
I’m glad to live within a 3-hour drive so that I can make it up to visit every now and then.
I only had a few minutes to work today, but I got the exhaust tunnel attached and the little pieces clecoed. Last night we went to visit Bart’s RV-8 Project. He had the whole EAA chapter over and cooked some burgers.
Brandon and Wesley look over the people hole while Wade looks over the luggage compartment.
Bart explains the technical aspects of the flex-titanium jingle converter and other gadgets.
Page says that there are too many TV screens in there.
Jerry looks over Bart's RV
I was fairly proud of the way the firewall turned out, so I started working on the boot cowl. Richard built the instrument panel top with a removable triangle panel so that the joint is on the inside of the windshield. Bob’s prototype is just the opposite, with the hole for the cabane struts cut from the forward end. I like Richard’s way better, if for no other reason than to keep rain from having a potential leak under the windshield. The top and large side pieces were easy enough to figure out, but when I started working on the small access panels and the tunnel it took a little bit more time to get it all figured out. The panel that goes behind the tunnel is one that I would like to remake, so I didn’t want to count on its holes for guidance. Bob attached the boot cowl with screws on his prototype, but my preference would be for rivets. I asked him what his thoughts were now that he’s been flying for 10 years and 1000 hours or more, and he said that he hasn’t removed the panels once. This was good news, so I’ll plan to use rivets. This is an especially easy decision in the context of the little removable panels that Avipro incorporated. If I take off those panels, the tunnel, and the front floorboards, I would have very easy access to anything in that area.
Today I spent most of the day working in the hangar and it was great fun. I spent about an hour sorting out the dumped pile of hardware, and this was a good experience. I got to be pretty fast with identifying the #6 and #8 nutplates. I also started going through the wing counting hardware and checking on things. I used the tackle box pictured in the last post to make an inventory of the #6 screws for the wing inspection panels. There are 94 screws for each of the fuel tank panels… I sure hope I don’t have to take those off very often!
List of contents at the bottom of the tub, awaiting royalties from land o lakes.
I also finished counting hardware for the floorboards and the rear bulkhead. I put them into a butter tub and listed the requirements for each panel on the bottom of the tub.
On the topic of floorboards, I disconnected the fuel valve and unhooked a few of the fuel lines. The Usher gascolator is 3.75″ tall without the quick drain valve on the bottom, which means that it won’t fit between the floorboard and the bottom of the airplane. It is nice to be able to keep the bottom of the gascolator above the bottom of the airplane for fire protection in the event of a crash that removes the landing gear. I might try and find another home for the Usher and buy one of Bob’s gascolators since his is short enough to fit by the valve. It looks like Richard’s solution was to put a quick-drain at the bottom of the fuel valve also.
I would like to do it differently...
I also spent some time working on the elevator trim tab pushrods. I was concerned about the kinks in the bend, since they might pose as potential stress risers in service. To address this concern, I considered replacing the entire part, but it made much more sense to just replace the bent section. I got out the old AC 43.13 to see what it had to say about reparing tubing. I had a piece of tubing on hand that was larger than the 5/16, so I went that route.
Tubing repair with a larger piece per 43.13
I made the calculations using the diameter of the original tube.
Since the OD of the original tube was 5/16, it was easy to make some calculations about how much to overlap.
Look, it’s really me working on the stuff!
Jared Yates building a Bearhawk!
It looks like a hungry fish!
Wait a minute, that's the wrong kind of fish!
That's Better!
Ready to Weld
Here is a bit more time with working on the firewall, with no substantial content beyond the last post. I just got back into town from a nice weekend of fishing, and while I was gone the firewall didn’t trim itself.
Since I’m finally caught up on inventory and counting for a while, I spent some time checking nicopresses. I checked each one with a go/no-go guage and marked the good ones with a green sharpie. They are all good, but that will help me remember to check in case I find one that isn’t green later (because I missed it today). I also spent some time looking over the door skins and counting rivet holes. I think I’m going to try to use pop rivets to hold the frames to the skins and to hold the windows in.
Engine Mount in Place
Firewall and Boot Cowl
Firewall Hole to Clear Engine Mount
Today I finished welding the elevator trim pushrods:
Before and After
Today I spent half an hour or so going through my list of bolts to buy again, this time with regard for the possibility of drilling our own solid bolts. It’s not very much time, but it’s all we could fit into the schedule today.
I called Bob today and asked him about the AN210-3A vs -3B pulleys. He said either would work just fine.
I also asked him about the braided fuel line, which is something I’ve been waffling about for a while. The issue is that the current fuel lines are braided stainless lines instead of solid 3003 aluminum lines. The braided lines are popular with the race car crowd, but they are about much heavier per foot than the same size of Aluminum wire. In fact, the weight difference of 40 feet of 3/8′ is 1.76 pounds for the AL vs 5.8 pounds for the stainless. I don’t have any doubts that the stainless tubing is up to the task, since the pressure ratings and chemical resistance are great. I am worried about the longevity of the rubber line inside of the stainless tube. Is this concern well-founded? Probably not, but I really don’t know. By using these lines does it mean that the fuel system will only last 132 years instead of 250? or does it mean that the fuel system will only last 5 years instead of 50? Racecars aren’t built for the long term- they are built to be reliable for short periods but not for long periods- but that doesn’t necessarily mean that the fuel line won’t still last for as long as I need for it to.
I have consulted several expert opinions about the tubing, so I figured I might as well ask Bob what he thought. To summarize, he said that it should probably be fine, as long as the resistance to auto fuel was good (which I would say it is). He added that it was much more expensive and much heavier and thus couldn’t imagine why anyone would use it instead of the AL. Richard’s point was that it was much easier to install than the AL tubing. If I were starting from scratch I would have stuck with the AL tubing, but since the stainless is already paid for, cut to length, and installed, I will probably stick with it for now.
Today I continued my hardware patrol. I have been through the entire fuselage and the control stick and have replaced and/or noted what I’ll need to get to continue. I can definitely justify the expense of a drilling guide since I have lots of bolts that are good candidates for drilling for cotter keys.
I changed the bolt on the trim wheel to one with a hole in the shank and feel much better about it. I removed the doors since the hinge bolts were a little bit too short. Rather than just swapping the bolts I just took the doors all the way off so that I could get in and out easier. I made a few bolt changes on the elevator and flap controls to account for length and/or drilled bolts. I also went through the landing gear bolts and installed the ones with the correct grip length, now that I know how to do that. I didn’t have the proper drilled bolts on hand but I’ll have the gear off several other times and can replace them next time.
Using the torque wrench for the first time on the Bearhawk
Comparing the M4 to the Bearhawk
This morning started out with a morning of Young Eagles flights. I got to see Buck’s Maule M-4 for the first time. He flew 8 of the 31 kids, which was pretty amazing considering that he only had 2 seats. He said that the max gross weight is 2300 and the useful load is about 800 pounds. He has the same engine that we will use, though we probably won’t have the same Hartzell CS prop. His airplane is certainly beautiful, and I can’t wait to finish ours since it will be a very capable young eagle hauling machine. For now I just helped out with the paperwork and logisitics.
Filing the Brake Pedal to fit between the tabs
In the last entry I was starting to install the right side brake pedals when I realized that I was going to need to relocate some tools from the clubhouse. I loaded up my home-made work bench and took it over to the hangar, complete with an assortment of tools that I will hopefully not need in the clubhouse as much as I will need in the hangar. I had to file the attach side of the pedals a little bit so that they would fit between the attach tabs.
I started to mount them but realized that I didn’t have the right bolts. I have several little boxes of bolts but was surprised that none of them were the right length! Actually, I did have several that were the right length, but they were not drilled. Since the brake pedals and cylinders are subject to rotation, 43.13 states that they must not be secured with self-locking nuts- that means a drilled bolt with a cotter key. Since I knew that I was at least going to need those bolts, I figured I might as well go through the rest of the airplane and see what else I will need. Shipping from the aircraft hardware stores generally isn’t free or even cheap.
"Reserving" the hardware anywhere that I can
I also started to notice that some of the bolts that I had were already comitted to parts and assemblies that were temporarily removed from the airplane. For instance, the bolts that hold the flight control cables onto the control horns were not on the airplane, but were presumably in some of those little boxes of bolts. I made a sweep of about half of the fuselage, adding missing hardware as a way to mark it as “reserved.” In the process, I also saw some hardware that was not installed the way that I would have installed it, so I also resolved those minor conflicts. For instance, the rudder stop bolts weren’t really quite long enough to stick through the nylon lock nut, so I switched them out.
The longer bolts with 1, 2, 3 threads showing.
This was the case in several areas, and I also saw a few “subject to rotation” applications that I would have prefered to use with castle nuts and cotter keys.
This bolt should have a castle nut and cotter key per AC 43.13.
This bolt is too short since it doesn't have a thread protruding through the nylon.
I worked for 3 hours today and made notes of which hardware I was definitely going to need, which included a few small pieces, and a few big ones, like the engine mount bolts. I was somewhat surprised to see that I didn’t have any of those, since I figured that they would have been part of the Wicks hardware kit. So, I went to the Wicks hardware list to look and see if they were originally included. There on the list are some AN6-46 bolts, which are about the right length and in the right quantity (5). So either the wicks list has changed, I have the bolts somewhere else, or I don’t have them. I repeated this same process a couple of other times, referencing the Aircraft Spruce catalog for the grip length of each AN bolt, measuring what the grip length needed to be, and sorting through drawers to try and find the right stuff. All the while I was making a list of things to buy so that I can make one order and get most of what I need.
I have several bolts that are the right size but undrilled, so I might try and find a bolt drilling jig. For example, I have enough -6 bolts for the landing gear that I will probably not need anywhere else.
I also noticed that on the plans Bob calls for a pulley as AN210-3A, which is equivalent to MS24566-3A. Yet, the wicks kit included only -3B pulleys instead of the -3A’s listed on the plans. So far I haven’t resolved this discrepancy. The Aircraft Spruce catalog says that the -a and -b pulleys are the same dimensions but have a different type of bearing in the center. I suspect that they are interchangable but will probably have to call Bob or someone else to figure that out for sure. The funny thing is that in a case like this I picture an attorney questioning a witness. “Why didn’t you use the pulley specified in the plans?” Maybe that’s an idea for the next episode of Law and Order. I know it’s terrible to think of it that way, but that is the image that comes to mind in this case, and also quite often at work.
Some folks say that building airplanes isn’t as hard as people make it out to be. This is quite likely true, and an experienced airplane builder can certainly separate a harmless or seemingly meaningless discrepancy from a major or life threatening one. That is one certain difference between a new builder and a seasoned veteran- knowing what is worth fussing over and what isn’t that big of a deal. Without the benefit of that experience, I have to chase down even the smallest discrepancies to learn which category they fall under. The pulley difference is certainly just the first of many.
I also took some time to scratch my head and figure out which tabs went to which flying wire on the tail surfaces. I used the front view on page 1 of the plans to note the angles of each of the flying wire attachments and to notice that the bottom of the diamond shape uses attach points that are welded to the fuselage. With that information it was easy to sort out the remaining 6 tabs, after which I labeled them with a sharpie pen and set them aside with their associated hardware.
I think the process of “reserving” hardware by attaching it where it needs to go is going to be well worth the effort. This should keep me from double-booking a particular bolt and not realizing it until final assembly. I still need to do the same thing for the rest of the fuselage and the wings.
Today I started to prepare the right side brake pedals for installation. I also spent some time shoveling the gravel on the hangar floor to try and help encourage good drainage of rain. I was glad to spend less time on workshop infrastructure and actually get to work on the bearhawk some.
Shouldn't he be using a vice to hold that part?
I noticed that the hole for the mounting bolt was a little undersized, as would be expected with a welded part like that. A quick pass with a drill bit cleaned it up. This would have also been a nice job for a reamer if I had one, but this part turned out fine with the drill bit too. Note to self- move the vice from the clubhouse to the hangar. You can’t build an airplane without a vice, at least not safely.
I’ve spent a few hours this week unpacking, building workshop infrastructure items, and taking inventory. I’m almost done adding shelves, racks, and work tables that I’ve made out of leftover building materials. One large corner rack is enough to store the ailerons, flaps, horizontal tail pieces, and most of the other parts.
Since Richard had not yet ordered an engine mount I requested one from Mark at Avipro back in September and just now got around to unpacking it. I was a little bit surprised to see that it had a fifth mounting lug, and I started to wonder if maybe it was actually a mount for the 540. It turns out that they started adding the fifth leg on the 360 mounts too, so it was the right one. I should add that I’ve been very pleased with the support that I’ve gotten from Mark, even though I wasn’t the one who wrote him a big check. I asked him about getting a set of brake pedals for the right side in hopes that I would be able to catch up with him at Bob’s Picnic tomorrow. It turns out that he wasn’t going to be going to the picnic but was glad to send me some for a small charge. While I was unpacking I found that Richard had a set already, so I had to call Mark to cancel the request. Anyone who can put up with that kind of trouble is worthy of respect and gratitude.
While moving the small boxes with hardware from the trailer I spilled a few of the drawers and had a handful of mixed hardware. I spent some time sorting through all of the drawers and making sure that the labels matched the contents. I certainly don’t want to buy hardware later that I acutally had in the wrong drawer.
I’m getting to the point now where I won’t have any excuses not to work on the airplane! I’ve spent several hours reading Richard’s Log and the Avipro Assembly Manual to try and see where we are going to start. I have several good starting points in mind and have also made a list of “things to be sure to do.” Likewise I have a list of “things to buy.”
Today I also installed a few flourescent light fixtures to help combat the shortening daylight hours. I’m sure that the guys from Alaska wouldn’t have any sympathy for me there.
This summer we worked on a place to work on the Bearhawk. Since there is an airport that is very close to our house, we decided to locate the project there. This is what the hangar looked like before:
It was a bit of a mess
And here is the “after”:
Almost Finished
Patrick and Bradley came to help us move the airplane from the trailer to the hangar.
We gave it a nice run up the runway to see if it would fly. No Luck.
Patrick and the Wings
Tabitha, Bradley, and Patrick
To carry them on the trailer we stacked some wooden pallets under a sheet of foam. This helped the wing clear the trailer fenders. Since we were only going a short distance and were not going on the raod it worked fine.
Now we just need to straighten up the hangar a bit and get started on the fun!
The hangar is almost done, and the poor airplane has spent most of the summer in the trailer. When we get ready to move it out of the trailer and into the hangar, things will be much easier if the fuselage can sit on its own feet. It took a little bit of time to look over the plans and locate the bolts, but now it’s all done. There is quite a difference in height with the airplane on the landing gear, especially with no weight to stretch the struts. Now it’s taller than I am, and it is easy to see why Richard wanted to take the gear off for working in his garage.
Since most engine companies require some lead-time, my first goal after securing the purchase of the kit was to start deciding on an engine. I knew that we wanted a Lycoming 4-cylinder, but that only narrows it down to a few hundred variants. I also knew that we didn’t want fuel injection, and that we wanted to be able to burn 100LL without the lead, which would have an octane rating of around 94. Those decisions, along with the elimination of the helicopter, aerobatic, and left-rotating options narrowed the field a bit. There were still several choices, so I started reasearching. I read the Beartracks articles about deciding on an engine, and did some online reasearch. Neither of those steps provided any great insight, other than that I knew that I wanted to choose a builder that I could trust to do a good job and support his work after the fact.
I spoke with Mark at Avipro to see what kind of OEM discounts he could get from Lycoming. He pointed out that there were basically three options that seemed popular among other builders. He could get a new 360 to sell me with the OEM pricing, I could buy an engine from an individual, or I could have Bob build one. He also noted that another builder had decided to sell a 390, and that the price was around $30,000. The new lycoming would be around $25k. The 390 is certainly attractive, since it has the same footprint of the 360, but has more power. I did more research about the compression ratio and octane requirements. It seems that the Lycomings have low compression cylinders that can run with the octane ratings of pump auto fuel, normal cylinders, and high compression cylinders that can only run on 100LL. Of course, the higher compression ratios produce more power, but are more likely to detonate on inferior fuel. I learned that the normal 8.5:1 cylinders can run on 93 octane or so, which is on par with premium auto fuel, and more importantly, with a version of current AVGAS without the lead. I’m personally betting that if 100LL ever goes away or becomes super-expensive, that the infrastructure will provide a clean, high quality fuel that has all of the good traits of 100LL (such as the long shelf-life and lack of ethanol and other goofy stuff). I think that this change will happen before we reach TBO on our Bearhawk, so I wanted to be sure not to paint ourselves into a corner that would require us to use leaded fuel.
Before long, I started to realize that even if I spent a year researching the 360 line of engines, I would still not know as much as an expert does about them. I was in the unique situation of having access not only to an expert on Lycoming engines, but also an expert on the Bearhawk- the guy who designed it. I called Bob and asked him a few questions. What was the current lead time? 9 months. What about the warranty? If it was our fault, we will fix it. What will the price be? Somewhere around $16k. Wow, that sounds pretty good to me.
I thought about it for another day or two, then realized that if I was going to put my faith in Bob to build an engine, I might as well go ahead and move forward with the order. I didn’t have any reservations about trusting his work, so I called him back the next day and learned about how his ordering process works. He wanted for me to prepare a written order and send it to him in the mail. This sounds like a great method, since it gives him a paper trail to follow. The trouble with such a process is that I didn’t know how to write the letter- but he knew that too of course. We spoke for about 15 or 20 minutes, and it went something like this.
The standard starting price for a 360 is $13,800, so start with that. What kind of engine mount are you using? The case for the conical is a little bit cheaper, the Dynafocal type 1 is $500 more. I would tell him what I wanted, or if I wasn’t sure, ask him about the merrits of the options. Once we came to a decision, he told me what to write and how much to add to the price. Here is a list that starts after the one listed above:
Constant speed capable crankshaft: Add $100
Prop governor drive on accessory case: Add $350
Vaccum Pump drive (for an alternator of course): Add $200
Skytec Lightweight Starter: Add $380
Flywheel for starter (while Bob probably silently remembers that his 360 Bearhawk didn’t have no stinkin electrical system at all) : $300
Angle Valve cylinders: $300
This modification is one that Eric also had on his engine, and Bob has done several like this. The angle-valve cylinders have larger valves and more metal in the head, which makes for better cooling, and will probably be the one modification that will be most different from other 360s.
The following options were important to note, but didn’t add to the base price: No preference for narrow or wide deck, carburetor, rear-entry oil pan and elbow to turn 90 degrees (moves the carburetor aft), overhauled cam and lifters, overhauled Bendix mags, overhauled ECI Cermanil cylinders, and the normal compression cylinders. Total price: $15,930. I sent the letter along with a $200 deposit, then followed up with a phone call a week or so later. That’s all there was to it! Will I end up regretting the choice to go with Bob or the options above? Perhaps, but probably not. That’s what I think anyway.
The paper version of my building log was progressing nicely for a while. I made a form block, ordered some aluminum, made a few MDF router templates, and other such fun things. I was just about ready to start cutting out some nose ribs when we went to Sun-N-Fun. We had a good time duing the usual Sun-N-Fun things, and my wife pointed out that it might be worth buying someone else’s project. This was a reference to this past fall when we spoke via email with the owner of an Avipro kit. In that case, the kit was in Washington, so just getting it home would have been a major undertaking. Additionally, it didn’t look like we were even in the same price ballpark.
She suggested that I call him to see if he had ever sold his kit. Her point was that if we could buy an Avipro kit second-hand, we could see a substantial price advantage to buying a new kit. In fact, even compared to scratch building, the price could be attractive. There are a few scratch-built projects that come up for sale from time to time, but the problem with those is that there isn’t much guarantee about the quality of work so far. At least with a kit, you know that the factory work was good. That means straight wings and good welding for example.
When we set out on this building adventure, the whole idea was to scratch build for the fun and experience, not as much for the financial savings. I wanted to be able to turn a coil of aluminum into a bunch of ribs, and steel into a fuselage, etc. I was expecting to spend 10 years or so, based on my estimations and research. Tabitha pointed out that by buying someone else’s kit, we would still have plenty of work to do, and we’d be flying much sooner and enjoying the airplane more.
I didn’t hear back from Washington, but I saw an ad for another Avipro kit on Barnstormers. The price was a little higher than I was interested in, but the ad mentioned some extras. The best part was the location. Just outside of Atlanta, it was about a 5-hour drive from our house. I sent an email to the owner and waited for a response. I got a reply early in the morning on Wednesday. The list of extras was longer than I had expected it to be, which made the higher price seem more reasonable, and the pictures that he had looked good. I arranged a meeting on the shortest timeline possible, which was on Saturday of that same week.
I spent the next several days working on all of the research that such an adventure would require. I spoke with Mark at Avipro to see if he would provide support to a kit after a sale to someone like me. He said he would. I spoke with NAFCO (since I had just met them at SNF) about financing. I also spoke with my bank and a couple of insurance companies. I checked on the pricing for a truck and for a place to store most of an airplane. Even if the seller would have been able to meet before Saturday, I wouldn’t have been able to get all of my own ducks in a row by then.
We left on Friday afternoon to arrive in Atlanta on Friday evening. Since it was Jamie B’s birthday, we met up with him and had some nachos. Then we spent the night at George and Susan’s house, which was a huge help. They were just a few minutes from the seller’s house. On Saturday morning we woke up early, just as Tabitha’s parents were arriving. They live just on the other side of town, which in Atlanta means an hour or two of driving. Don and I went to the seller (Richard’s) house. Richard was very polite and had great answers to all of the questions that I was able to think of. We rode together over to his airport (KVPC) and took a look at the wings. We agreed to a price and I left a deposit, along with a promise to come back and pick up the airplane in a week or two.
The first step was to call NAFCO and start the process of the loan. To fund the loan, they wanted for me to reserve an N-number so that they could place a lien on it. This didn’t make much sense to me, since there wasn’t an airplane associated with the number. Somehow it all works out, and so I put in the request. Kevin at NAFCO seemed to think it would take a couple of days, meaning that we might have been able to pick up the airplane after just one week. It actually took the FAA 10 days to process the request! As always, they move at the blazing speed of government. At this point we also met with Claude, the manager of the airport that is very close to our house. We worked out our plans with him for building a hangar and for temporary storage for the airplane.
My first plan for storage was a shipping container. I thought about buying one and using it as part of the structure of the hangar. The 40 foot version was going to be about $2300, which was about as much as my hangar budget in total. I found that I could rent one for $100 per month with $300 delivery. Just before delivery, I learned that my local friend in the trucking business (Tommy) could rent me a trailer for the same rate with no delivery fee. The trailer would be higher off the ground, but the same height as the Penske truck that I was using to move the airplane. It was also 53 feet long instead of 40 feet, which was even more room to spread out in. Tommy worked out the trailer delivery, and we processed all of the loan paperwork.
The best insurance price was with AVEMCO, and they had flexible terms for a project under construction. With the insurance scheduled to start on Friday at midnight, we finished the wire transfers on Friday afternoon. This was one day less than 2 weeks after our last trip to Marietta. On Saturday, we started early at NC27 for the Lenoir Aviation Club work day. We left there at about lunch time and made it to Greenville SC at about 2:00pm. We picked the truck up in Greenville because it was much cheaper than the Atlanta area. The other problem that we had was that most Penske offices close early on Friday, so by picking the truck up half way, we were able to leave later in the day. We saved about $150 off of the truck rate, and burned about $50 in fuel to drive the truck from Greenville to Marietta.
We made it to the VPC airport at about 6:00, and I had a bit of a headache. As that headache soon deterioated into nausea and such, it occured to me that I hadn’t had much to eat. After a mountain dew and a few minutes of digestion, I was back on track. We met Tabitha’s parents there, and loaded the wings into the truck.
I don’t have a picture of just the wings in the truck, so above you can see one of the whole load. It was a 22 foot truck, and there was plenty of room. We used the original Avipro styrofoam to pad between the leading edge and the floor. We used two straps to hold each wing to the side of the truck, and it worked well. We also put foam between the wing and the wall.
We made it to Richard’s house at around 8:00pm, which was an hour behind our original schedule. We had a couple of cousins from the area there to help, and they were very helpful. Richard and his wife Sharon also helped with packaging and padding everything. As it was assembled, two people could hold the front of the fuselage up comfortably. Since there are stringers on the bottom of the fuselage, it can’t sit on the ground. We had Tabitha take the wooden sawhorse support up to the front of the truck, and we put two people in the truck to receive the fuselage. We let the tailwheel roll and had Richard doing the steering. We had the firewall almost against the bulkhead in the truck, and used a total of 8 straps to secure the fuselage in place. We didn’t actually set the aft 4 straps until the very end, which allowed us to keep loading things into the cabin area. The wingtips, flaps, ailerons, front seats, and lots of other stuff went into the cabin. The control surfaces and other flat pieces went into a pile behind the fuselage. I used a series of wood screws to secure the strap hooks to the wooden truck floor (and to secure the front sawhorse to the floor). It took two straps to hold that stack down, and then another two straps to hold the main landing gear in place. The goal was to be sure that nothing would be able to move inside the truck, either to damage itself or to damage any other parts (like the wings). We were finally ready to go at around 10:30 pm, and after a meal with Richard and Sharon at the Mexican place we were ready to go to sleep.
We slept at George and Susan’s again (thanks!) and left the next morning at around 9:00am. I made it to the airport with minimal stops and was able to back it up directly to the storage trailer. Not a bad parking job if you ask me! Unloading the Penske was no big deal, since it was just a matter of transporting the items across a small gap. The wings and fuselage required some help, and Wesley, Danny, Patrick, and Richard (another Richard) all helped. With all of the Bearhawk parts in hibernation, it was nice to take a relaxing deep breath and let it all sink in. It had been quite an adventurous 2 weeks!
Now we just have to tear down the remains of the old hangar that’s in our spot, and build our own. Nothing to it!
On March 15th 2009, Tabitha and I went to the Mississippi Coast to visit Eric Newton and his Miss’ippi Mudbug. I had seen a few completed Bearhawks, but Tabitha had not been able to sit in one yet. On this particular visit, I was going to be in Gulfport for work, and my Dad (who also lives on the MS coast) was available to go with us.
At this point I had read the first two of Eric’s construction books, so it was great to see the famous Mudbug in person. I had not yet read the third book, though I have read it since then. Eric was a great host, and I found myself wondering if he ever gets tired of answering the same questions over and over again. Who knows, maybe that’s part of why he wrote the books!
He offered to take us on a flight, which we didn’t expect but were glad to accept. You can see from the pictures above who got to ride shotgun! Actually he even stopped and let us switch seats so that I could fly some too. Getting to ride in Eric’s Bearhawk was a hugely important step in our decision process. Since his has a “Bob” O-360 and a fixed pitch prop, it represents the “lean and mean” side of the Bearhawk, as opposed to the “just mean, not lean” versions that have 540s. The runway was soft, and Eric said that his takeoff performance was usually much better, but we were still impressed. The runway was so soft that it actually led to some mud splattering on the bottom of the wing.
Since I was in the back seat for the first bit of flying, I was able to spend some time evaluating the view and the sight pictures of the various phases of flight. Our first impression in this area is that the horizon sits much higher in the forward-looking picture than it does in most of the other single engine airplanes that I have flown. Tabitha and I both agreed that this was a plus- it makes the windscreen feel more like a picture window and less like a skylight.
Another important observation from Eric’s ride was the prop RPM. Back when I used to work on airplanes in my college days, I was always sure that I didn’t want to own an airplane with a constant speed prop. The expense, weight, failure possibility, and maintenance were my reasons. When I first started talking with Bob about the requirements for the BH, he said that it really can benefit from a constant-speed prop. To paraphrase, he said that while most 2-place airplanes don’t see enough of a gain from the CS, it makes a difference on the 4-place. (I’m not sure about what the number of seats has to do with it, but I think he was referring more to the total weight of the airplane) He did say though that it would still operate just fine with a fixed pitch prop. A comment like that doesn’t sound very convincing unless it comes from someone like Bob- since he seems to have equally large aversions to weight gain and dollar expenditure. If his answer was “I really don’t see why you would need it,” then I would have know that a constant speed prop would be an unneccesary luxury. But since he seemed to be pro-constant speed (or perhaps just not anti-constant speed?), that made me start thinking about it. Those who have spoken to Bob about such decisions will know what I mean.
Flying with Eric was perhaps the final selling point that convinced me to go the constant-speed route. The climb performance was great, but it was very easy to get to redline RPM in cruise speeds. This meant reducing the throttle to keep the prop speed down, which of course means slower cruise speed. The mudbug is still a great machine with amazing performance, but it has a very broad speed envelope, and as such it requires quite a bit of compromise to keep a single fixed-pitch prop well-suited to the entire range.
Eric took us south to show us his neighborhood and the coast, and he let Tabitha do some flying. At the time she had only had one or two recent instruction flights, so she was still very new to flying. She first noticed how much more responsive the BH is when compared to the Skyhawk that she had been flying. The ailerons and pitch are much more crisp, and the rudder won’t let you forget that it’s there. I would compare the feel of the controls more to something like the Luscombe or Taylorcraft that I have flown in the past. When we switched seats, Eric let me do some slow flight and stalls. He has not been able to extend the flaps to the 50-degree setting, simply because it is too dificult to get the lever to that position. Eric’s not built as a weak type of guy, so that should tell you something about how much effort is required! In fact, he had a good point when he said that he’s reluctant to try too hard to get the flaps to that position, since if he is successful, he may not be able to retract them. So we deployed the flaps to 40 degrees (which is still an extreme amount of deflection), added power, and watched the pitch angle climb as the speed went down. Holding altitude during this transition was easy for me, even on the first try. I was surprised by the responsiveness of the controls even at such low speeds. We just plowed along at low speed for a little while, making some turns. The airplane flew well at those speeds, though it was a hand-foot affair, just as it was at higher speeds. The stall itself was a non-event, just as others have described it. I wasn’t sure if I could believe Budd’s hype about the low-speed handling characteristics of the BH, but let me tell you, it’s true.
Here are a few other observations that I remember from flying with Eric. First, the BH seems to be the kind of airplane that will take an hour or two to get used to before I become graceful with the coordination of aileron and rudder inputs. I felt the same way about the lighter classics that I have mentioned above. Riding in the back seat with the windows open gets pretty windy. In the front seat, it’s loud but nice at putt-around speeds. The cockpit visibility is excellent, and the BH will make a great occasional aerial photography platform. The stick-time handling of the BH is good enough to enjoy the flying just for the sake of flying. I wouldn’t say the same thing about any Cessna product that I have flown, though I would say the same thing about the Citabria and Beechcraft airplanes that I have flown. The cockpit is very roomy and not cramped at all. The noise level of Eric’s straight pipes and no noise insulation is still acceptable, at least for the short time that we flew. 10 hours per day of cross country might change my mind. The 360 is plenty of power.
We were very greatful for a chance to get to see the Bearhawk in action! This was just another example of Eric’s great generosity and promotion of the Bearhawk. He’s a great asset to the homebuilding world!
My good friend Patrick is just starting to build an RV, and he gave us a tour of his shop and progress.
Here, Patrick is lurking in the inky shadows. Since the flash feature is broken on my camera, and since the shiny new aluminum skin was reflecting bright sunlight, you can’t see him very well. He is building the RV-7, which of course has a much different mission than the Bearhawk. The wing construction is still very similar though.
You can see that he has some nice carpet squares to pad the bench around his C-frame dimple/rivet station.
Apart, together 1; Apart, together 2; Apart, together...
Patrick says that airplane building involves a lot of putting things together and taking them back apart again. Sort of like those exercises we used to do in elementary school. Here he’s building up the spar for the horizantal stabilizer.
Here is a view in the plans of the completed RV-7, conveniently posted for motivation and reference.
You can see that the RV plans are much more detailed than the Bearhawk plans. The RV has a step-by-step assembly process that is laid out clearly by the manufacturer. The Bearhawk is a bit more of a puzzle, and part of the challenge of building it is filling in the blanks. This is another major difference between Patrick’s project and mine. I wouldn’t say that one philosophy is necessarily better than the other, but rather just that they are quite different.
Here he’s telling Tabitha about how his fingers are sore from using a 1/4″ drill bit for hole deburring. Emily had been studying when we arrived, and we came on very short notice! Hopefully one day we can fly both airplanes to Oshkosh. Patrick can take Emily, and we can take all of their stuff. They’ll have to wait for us at the fuel stops though!
Books!
Each project has to start somewhere, and this one has started as a pile of books. My wife told me that the traditional gift for a first wedding anniversary is something made of paper; so my gift came as an order from the EAA bookstore. They included the four Tony Bingelis books, the EAA welding book, Richard Finch’s welding manual, and AC 43.13 1b.
My first introduction to the Bearhawk was at the Kissimmee Airport on the Monday before the 2008 Sun-N-Fun fly-in. Avipro was hosting the event at Jim Clevenger’s Hangar, and I got to talk with Bob Barrows (the designer), Budd Davisson (representing Avipro), Wayne Massey (a scratch builder), and several others. You can see pictures at http://jaredyates.com/pages/bhkism/bhkism.shtml of the whole day.
Before Oshksosh in 2008, I was interested in the Bearhawk, but faced a bit of a dilemma. I didn’t want to find the money to buy an Avipro kit, and I didn’t have the skills or knowledge to scratch build one. The educational resources at Oshkosh changed all of that. I didn’t know how one could possibly form ribs, until I went to a seminar about forming ribs. Then, it sounded pretty easy. I wasn’t sure about welding, until I spent some more time in the welding workshop. One by one, my mastery of the various skills became a bit more realistic. I wouldn’t begin to say that I had mastered them at that point- rather, I just learned that I could certainly be able to master them in the future. You can read all about my 2008 Oshkosh experience here: http://jaredyates.com/pages/oshkosh08/oshkosh08.shtml
We had a bit of travelling to do just after Oshkosh, but I was convinced that I wanted to try scratch building a Bearhawk. Just about that time, Jeff Walin put his Bearhawk materials on Ebay. I purchased his plans, a copy of Russ Erb’s CD, and Eric Newton’s first 2 manuals all as a single package. I opened the box on the day that we got back from a month of traveling, and the fun had begun.
The time elapsed from the picture immediately above until the picture at the top of this entry was about 3 months. This phase was one of information gathering, where I was still reassuring myself that I really wanted to undertake such a project. All together, that process has almost taken a year.