At the Polyfiber booth, there was a display and advertisement for a covering iron that looked interesting. Someone please buy one and let us know how well it works! The website is https://fabricprousa.com
Continuing our coverage of alternative wheels and brakes, here are some photos of similar systems in use on non-Bearhawk airplanes:
Source: 2026 Issue 1 Beartracks
Ryan Spencer is the owner of the 4-Place Bearhawk originally built by Phil Johnson, N125PJ. Last month he made some videos and a Facebook post about using wheels intended for ground Utility Vehicle wheels. There is also a more detailed video of the installation here. Ryan sourced adapters from https://www.stolwheelz.com/ which bolt onto the typical Cleveland/Alaska Bushwheel style brake disk. That adapter then allows for bolting on a large variety of wheels that are manufactured for side-by-side utility vehicles. The machined aluminum adapter hub uses sealed ball bearings, unlike the tapered roller bearings that we see in more traditional aviation setups. There are several tire options, some of which represent a weight savings over similarly-sized Alaskan Bushwheels. Ryan is using a wheel that allows for a bead lock so that he can reduce the tire pressure.
The Facebook post included some discussion about the structural loading of the wheels and the axle, and some questions about whether they would be as dampening as the ABWs, with their shorter sidewalls. These were good questions with good discussions, and while these wheels might not be universally better than the most expensive ABWs in every regard, they provide a significant cost savings and for many types of operation, might prove to be good enough and a good value. As a fellow Bearhawk operator I’m grateful to Ryan for sharing his experience. Compared to even traditional airplane tires and not ABWs, today’s price at Aircraft Spruce for just a single 850×6 inner tube is $227. One 8.50×6 tire is $377. I’m interested to keep an eye on Ryan’s experience with these adapters, and I hope they will serve as a viable alternative.
Here are a some pictures of my Bearhawk 4-Place. I bought her about 2 years ago while I was doing my PPL. After completing that I trained on this plane. What a wild thing compared to my school plane, which was a very tired C172, which I did not like at first but actually became very fond of the old girl.
After that, onto this girl. I love it. She has an IO 390x engine with API fuel injection. Rated at 210hp. 4 fuel tanks with usable 69
gallons which gives me amazing endurance. Definitely needed in Kenya. It has a Dynon Skyview system with autopilot. Performs brilliantly even with 3 adults, full fuel and loads of camping gear. I operate out of a dirt strip at 6250ft MSL and most days DA is about 2000ft above
that. I’m still a very junior pilot and so fly very conservatively as I learn her ways. Best regards and looking forward to meeting more Bearhawk flyers and learning more about the planes.
The airplane was originally flown in the United States and subsequently imported to Africa.
Brake Selection
You’ll need to have some brakes and tires fairly early in your build process if you are planning to install the gear legs and keep the plane on its gear. The best strategy is to find a run-out set of any kind of tires that will fit your wheels. Use those until you are ready to fly, which may be years from now, and then purchase a fresh set just before your first flight. Rubber ages unfavorably whether you use it or not. Check at your local flight school for a set of 600×6 tires, which is the size most often used on the main wheels of small Cessna trainers.
Just as with choosing an engine, deciding on your wheels and brakes will require deciding on how you plan to operate the airplane. The financial outlay is not as big as it is with an engine, but it is still significant. The main players for the 4-Place Bearhawk will be Cleveland, Alaskan Bushwheel, and Matco.
Cleveland sells two suitable wheel and brake kits. The 199-62 package will fit large and small tires, and the 199-60 kit will only fit 6.00×6 tires. There are two differences in the kits. The 199-60 has a brake disk that sits ¼” closer to the tire, and the torque plate has shorter lugs. This set is ideal for wheel pants, since the overall width is less. Most Bearhawk builders will be better suited with the 199-62 package, which includes the deeper brake disk and torque plate with longer lugs. See 2016 Q2 Beartracks for more details on the part numbers.
Alaskan Bushwheel makes a wheel and brake package that is interchangeable with the Cleveland 199-62, and sometimes their price is lower. In any case, they are still very expensive.
Grove wheels and brakes are very popular with Bearhawk builders. They are available as single puck brakes (for use with normal aircraft tires up to 8.50’s) or double puck brakes which are required if you ever want to use bigger tires than 8.50’s. Groves are available in aluminum or magnesium.
Matco also offers a package that is suitable for the Bearhawk.
Tire Selection
There is a real tendency to think big tires are necessary to land on grass and dirt runways, which simply isn’t the case. The normal 6.00×6 tires will handle most surfaces 95% of Bearhawk builders will ever see. If the landing surface is called a runway by most people, then the smaller tires are fine. If you’ll be landing on rutted or rocky surfaces, the bigger tires will be necessary. Moving up to 7.00×6 tires will give you added margin and will cost almost nothing in performance. Below is a chart comparing the commonly available tires and their rolling diameter. Notice the big jump from 8.00 to 8.50 x 6.
| Tire Size | Diameter | Width | |
| 6.00 | 17 | 6.3 | |
| 7.00 | 18.25 | 7 | |
| 8.00 | 19.2 | 7.95 | |
| 8.50 | 22.1 | 8.85 | |
| 26” Goodyear | 26 | 10 |
Tailwheel Selection
The Bearhawk is designed with the main wheels pretty far forward, which greatly mitigates the chances of nosing the plane over. The other side of this trait is that there is a lot of weight on the tail. Many tailwheel assemblies that were designed for light taildraggers are simply not up to the task. There are only two tailwheel options that we recommend. One is the assembly designed by Bob and available from BHTailwheels.com. The other candidate is the Scott 3200 (pictured last), though many builders don’t find the Scott to be as cost-effective.
Source: 1998 Beartracks, Bob Barrows
Dear Bob,
This is a formal invitation to come visit us in this area on your trip to Alaska. It is sure to be an exciting adventure and I am envious of you actually planning it. I often talk about going to see my old flying instructor (Ray Krumrey) in Old Harbor, Kodiak Island but haven’t got there yet. It is one of my flights of fancy to fly there in the Bearhawk and do a big impression on him. Ray is a great guy and we became good friends as a result of flying.
David Giles (#222) wants to meet you. He is an SDA Minister who flies an RV-6 he built and is barely started on the Bearhawk his son and he are doing. He is a really nice fellow – one of your fellow Countrymen originally – and he visits me fairly often. I’m sure that there are others who would like to meet you too. Another reason for coming is that you will be right on course for the “Rocky Mountain Trench” which will take you right to your destinations in Alaska. It will be a comfort to you to know that you will be flying over a lot of paved road (emergency landing strip). Be advised that GPS is definitely a good idea as there are very few other Nav aids in this North Country once you get 300 miles North of the Border. I haven’t actually been over but I am told it is great!
Progress on the Bearhawk is slow and steady. My Son has already dubbed it with the moniker “Times Two” since I have made so many things twice! I keep telling him that those were “test pieces”! However, the fuselage is largely done and I am working on the little bits and pieces necessary before I move it off the reference plane of the dead level and flat workbench I built from three 16ft TGI floor truss crops. Used 4×4 legs with adjustment bolts in bottoms. Covered top with 4×8 plywood with one foot overhang. Using other shipping plywood, I made shelves between the truss ledges. This works well as they slide out and is a handy place to store pieces of tube right under the bench top. Simple, strong and flat and it can be disassembled as I put the legs on with lag bolts and left about 4″ edge overhang!
Have all the wing pieces built but have not done any skinning of them. I got tired of pounding aluminum and switched to building the fuselage. This winter I hope to make the tanks and a lot of the hardware pieces like seats, controls, levers and such. The main idea for me was to have a project to keep me out of mischief! It has worked but I have also derived a great deal of enjoyment and satisfaction from building (to this point).
Bill and his wife spend their winters in Arizona. He got me onto this design of yours and has been a great resource with all his experience. He and another of his friends are building an RV-6 each. He likes to get upside down once in a while, he says! He sold his Stearman. The Airline driver who bought it had to get some old timer to fly it back East because he couldn’t handle it. After getting it home, the nerd wrecked it within a week! Wheel landed on wet grass area and hit some puddles of water. End of story! $50,000 later … ??? All the best,
Rod Dressell – *190 – Creston, B.C.
Dear Bob,
Do we need to consider increasing the vertical stabilizer/rudder size, or add a dorsal (ventral) fin for use with floats?
Thanks,
Bob Thomasson – #280 – Santa Rosa, CA
Bob,
The rudder will not have to be altered in size to accommodate floats. The vertical fin area may have to be increased to counter the side area of the floats. A dorsal fin bolted to the bottom of the fuselage will accomplish this. Weld in a bushing for a 5/16″ bolt at station G-K and use the tail spring attach fitting to bolt on the dorsal fin. I am not sure as to how much fin area is needed – you will need to experiment, and talk to other float pilots. Bob
Bob,
Keep up the good work, your newsletter is invaluable! … Still working on the wings.
Thanks
Brad Young – #229 – Spearfish, SD
Dear Bob,
Just a reminder that we wanted to be put on the list as one of those who would order struts from you. Fritz and I put the wings on last weekend. We had the fuselage setting sideways in my garage with one wing in and one wing outside of the garage. The door was covered with plastic sheet so we could heat the place. It took a day or so to get things squared up and the wings are off now and tucked away in their rack until next spring when we can paint them.
We hope to be done by the first of April ’98 if things go well.
Tom Lee – *98 – Winona, MN
Dear Bob,
Well, I’ve had your Bearhawk in the back of my mind since I read the Sport Aviation article 2 years ago. I poked around the airplane a OSH last year but never got to meet you or talk to you about it.
My RV-6 is almost rebuilt – after being run over by a Chevy, believe it or not – and I am contemplating a project where I can learn some new skills.
I work for Dick VanGrunsven and can get almost all the materials needed very reasonably along with access to all the metal forming equipment you could ever want.
So – what I’m thinking about is a minimal, light airplane – but with a battery and starter, hooked to the lightest six cylinder engine I can find. Say an 0-470? Do you think this is practical for a guy with minimal welding skills but good teachers?
Enclosed is a check for your flyer & – I hope – a collection of past newsletters. I write the one for Van’s, so I like to read other peoples! Addresses of Western OR or WA builders would be appreciated too. Thanks.
Ken Scutt – Hillsboro, OR
Ken,
Thank you for your letter and the request for information on the Bearhawk. It is interesting to hear that you work for Van’s Aircraft and write his newsletter.
Many builders of the Bearhawk are doing this airplane as a first time project and learning the skills as needed, from knowledgeable EAA members.
Please find enclosed a data sheet, photo, a selection of newsletters and a list of builders in your area.
Thank You – BOB
Dear Mr. R. Barrows,
I have received the drawings for the Bearhawk: The drawings are beautiful!
For your super excellent work – I send my graduation!
Yours Faithfully,
#209 Stefan Kjorcev-#308-Oberglatt SWITZERLAND
Tim Neal #209 sent in this photo of his project.
A few questions as my fuselage is well on and I will need some answers to keep going.
1) For the rear door modification – you specify .032 alloy, would .025 be too light?
2) Will you be supplying a detail of the main doors in the newsletter?
3) What weight of alloy do you use for engine cowling – .020 or .025?
4) Routing of fuel lines from tanks and do you run separate line from the front and rear draw off points on tank and join to one in cabin or how do you do it?
5) Your method of attaching plastic sight tubes for fuel to alloy tank tubing?
6) Have you a fore and aft adjustable for front seats to seat long and short legs?
7) Some friends of mine at Oshkosh talked to you and took some good photos, a question on your exhaust system, by the photo: you appear to have 4 separate pipes, are they straight out and what is the noise like?
8) The trim system on your drawing #22; Do you need a friction disk or is there enough friction in the system? Is the trim chain a 1/4″ with a 12 tooth sprocket?
9) Positioning of wing attachment fittings on fuselage, the 32″ dimension is OK but the parallel dimension for both sides in relation to the spar fittings and lining everything up, my spar fittings are pilot drilled 3/16″, presumably the fuselage fittings should only be pilot drilled at this stage? These wings are quiet large compared to my Tailwind, so will you be giving a rundown on the fitting, lining up and setting dihedral, drilling and reaming holes to size, etc.?
10) Lift strut fittings, I have made up the wing end channel fittings, the double joggle in the fuselage end is somewhat more complex. What was your method of shaping? Also do you square cut the ends of the struts or angle cut to angle of wing and fuselage?
11) 1 know from a previous comment that you prefer a control stick and my Tailwind has a stick but I really want to have a yoke system with the Bearhawk. Much easier for females with a dress on and the floor remains relatively free of obstruction. Could I copy something?
12) Finally, the need for a fixed step up into the cabin like many aircraft have, my wife is not that tall.
Regards,
Ray Thurston – #5 – Blenheim NEW ZEALAND
Ray,
Good to hear from you again.
Regarding your questions:
1: .025 should be OK. 032 is better for the wear and tear resistance.
2: We will cover door construction in a upcoming issue of Bear-Tracks.
3: .025 is used. You may use .032 for the top.
4: The tubing is joined below lower front door frame with T section. (Upcoming newsletter)
5: Below is a sketch of what I recommend:
6: Yes – the same as a Piper Tri-Pacer. This system is nice in that as the seat moves forward it also rises lifting the shorter pilot up to see over the instrument panel, as it goes back the seat lowers giving the taller pilot more headroom.
7: I have 4 straight stacks out of the bottom of the cowling. I am told that they are loud but not unpleasant. I do wear earplugs.
8: No there is enough friction in the system.
9: See here.
10: I’ll cover the correct method for bending the end fittings in the next newsletter. Cut the strut ends square.
11: We do not plan to design such a system but you could copy the Tri-Pacer or a Cessna design.
12: A step is a builders option – check as designed on other tube fuselage aircraft.
Thanks for your letter and send us some photos of your project! ~ BOB
Bob,
I want to thank you again for your time and sharing techniques. I made another set of fluting pliers and they make a nicer crimp. I am also doing my rib lightning hole flanges a lot better, no warped ribs.
The idea of putting tape on the fluting pliers to keep from marking the aluminum really works. Thanks.
J.T. Newbegin – #284 – McAlpin, FL
Hi Bob & Mike,
Just got your newsletter, sounds like a lot of great activity with the builders. It also looks like you are getting close with Proto II.
I have enclosed a check for $250 for a pair of wing struts. I will be looking forward to getting them.
BEARHAWK 075 has fabric on it now. I am taping at this time and hope to have everything in silver in a couple of weeks.
The engine has not been installed yet, it will be a Ford Dura Tech 24 Valve 3.0 V6. I am converting the engine myself and have had to do a lot of searching to find an ignition/fuel injection computer system that I felt comfortable with. The original Ford system has too many extra input requirements and no adequate wiring diagrams.
After the engine is roughed in and the fuselage is on the gear I will send you some photos.
Have a great day!
Tom Yeomans – 075 – Richland, MI
Tom,
Sounds like you have made quite a bit of progress on your project. A lot of the builders may have an interest in more information about your Ford conversion. Keep us updated. ~ Mike
Chuck Frasier called the shop a few weeks back and had a question about the tail feathers. He was fitting up the elevator and found that the trim tab arm is rubbing the T-14 spar tubes on the horizontal stabilizer and the elevator.
To fix this you put a 10° – 15° bend in the trim tab arm under the elevator T-14 tube. You should clear the spars by a bit more than 1/4″.
Reference drawing #20.
Enclosed is a check for one pair of struts. I have finished a full review of the plans and worked out a material list. I bought all the .025 aluminum I’ll need and I am accumulating the other material.
Still trying to get my garage finished and other projects I had already started so I can start pounding out ribs. Is there enough strength requirement for using the 1/2″ X 1/2″ rib attach angles or can I make more than one forming block and bend up the end of ribs for attachment? I would rather make more forming blocks and save some weight unless the attach angles are required.
I have not seen in the October Sport Aviation article or in Bear-Tracks or in the plans any information on testing. Has the plane been flutter tested? Has the plane gone through flight testing such as dives to Vne, stalls at both ends of the envelope, light weight to gross?
Thanks for the help. Would sure like to see N6890R if you stop near Seattle on your way to Alaska this year. A visit to the Arlington fly-in would sure be nice for the west coast builders who can’t make it to Oshkosh but would like to see the BEARHAWK!
Wayne Hallburg – 266 – Centralia, WA
Wayne,
Thank you for the strut order – we will be shipping the struts (hopefully) before you read this. About your questions: Yes you can eliminate the angles if you wish but you must take into account the varying widths of the spars at different locations. The flutter testing was done during dives to Vne speed at 180 mph and stalls have been done at 1500 lb and 2400 lb gross with no unusual characteristics shown.
We are planning on attending the Arlington fly-in this year and hope to see you there. -Bob
Bob responds to a fax from Ray Thurston :
Ray,
In reference to your fax of 01/16/98 about the flap control assembly drawing #28: In checking the fit up on the BEARHAWK now under construction in my shop I did use the arm length as shown on drawing #28 but I offset it as shown below. In addition I moved the shock strut attach fitting (see drawing #24) up as high as I could and still have room for the rod ends HMX-76. This all gave me the clearance that I needed. ~Bob
Dear Bob,
Enclosed is a check for a pair of wing struts. I am also enclosing a photo for the newsletter. It is a picture of a die, made by Doug Jasper, for bending the flat plate pieces for the wing hardware.
It worked quite well and I think it is obvious how it works. He spaced the bars so that one side will bend .063 and the other side .080. I filed a radius on the edge of the male die, which is 3/4″ key stock, so one side does .063 and the other .080.
I just finished my steel wing hardware. I brought my flap and aileron mechanism to my EAA Chapter meeting last night and everyone commented on how nice they looked. Even had one person praise you for the engineering and how smoothly the mechanisms worked. I am now finally beginning to assemble my first wing. Slow but sure.
Pat Fagan – #232 – Pearblossorn CA
Dear Bob,
I am confused about the turnbuckles for the elevator where connecting to the bellcrank.
Drawing #26 says AN 135-32S Turnbuckle. I just ordered as specified and find on arrival when I was doing a trial fit that the pin eye is .25″ and yet the bellcrank says 3/16″.
The Cable eye likewise seems larger than required at .281″.
All parts are stamped and the turnbuckle is definitely AN135-32S. Would AN135-16S be more appropriate? Could you let me know?
Ray Thurston – #005 – New Zealand
Ray,
The AN 135-32S as called for in the plans is correct. You will need to make a bushing from 1/4 ” x .028 4130 tube, and use (2) AN960-416 washers as shown. ~Bob
While at Sun N’ Fun several builders brought pictures of their progress. Below is a photo of Larry Williams #184 project. Larry is using a Continental 0-470 for power. ~Bob
Bob,
I received the wing struts Saturday and the plans for the struts a few days later. Thank you. I received the cap strip material I ordered from Wicks last week and I bought some rivets to practice with over at the fly-in and flea market at Hampton Airfield on the coast of New Hampshire. I am a little nervous about starting the spars but I am sure that it will all go fine.
A friend of mine has landing gear and the gear shock struts that go on a 1947 108-2 and we were wondering if it would work on the Bearhawk. If so is it as strong as your design. What are your thoughts.
Sonny Cilley – #234 – Royalton, VT
Sonny,
I am sure that your spars will come out fine. It is just a matter of following the directions on the plans and in the newsletters.
The 108-2 landing gear system that you have is strong enough for the Bearhawk – but doing the engineering work to install them would be quite involved and time consuming. The time spent adapting the Bearhawk to accept the Stintson landing gear would be greater that just building the gear shown in the drawings. ~Bob
Bob & Mike,
It was great meeting both of you at Palmer, Alaska and I immediately dived into the plans and newsletters. Wish I had had the chance to study before going to Palmer but that is life in the frozen North.
As stated at Palmer, here is my check for a set of struts and drawings. I also want your wing construction and photo log, which will answer many procedural questions, I’m sure. May as well get the Disogrin ring set as I don’t want any delays for parts. While I have not yet ordered my 4130 and Aluminum, I have sent for all the books and catalogs recommended, made up a material list, made the wing rib form and acquired jig material (table) and a good shop to build in. All this since getting back from Alaska on August 12th. Being retired has its advantages.
I was in Alaska for about two months installing the water wheel power project for my friend. We are still evaluating the project, though the initial data
is quite favorable and slightly exceeds expectations after some modifications.
Hope all is well in Fincastle, do you think you might do Arlington again next year? I would like to have a list of Washington builders list and when available. In the meantime I will be attending the local EAA chapter meetings which I understand is loaded with talent.
Is there a drawing for the float hard points?
Just so I don’t miss any bets, please let me know your pricing for an 0-360. Thanks and looking forward to building.
Jack Piggott – #347 – Sequin, WA
Jack,
Thanks for the photos and letter. The struts have been mailed out along with the drawings and the o-ring seal kit. You should unwrap and oil down the struts when you receive them before putting them in storage. Mike has sent you a photo log that you should receive soon.
It sounds like you have really been chugging along on your project. Keep up a good head of steam because it is a long haul.
Regarding the float attach points, see the 1996 issue for rear float attach location, and use the front landing gear fitting for the forward attachment point. The fitting at the rear can be made just like the landing gear fitting if you like. We will work more with you on this area as needed. Do you have any idea what kind of floats you will be using? ~Bob
Mr Barrows,
Just a letter of introduction that is long over-due. I recently purchased plans s/n 188 from Mr Serge Valin the package also included the photo log and newsletters to October 1996. Enclosed is a check for all the back issue that I am missing and a subscription for 1999.
With any luck this winter will see me pounding out ribs. If there are any builders that are close to Detroit, I have access to a 10′ shear and brake for spars.
Mark Deacon- *188 – Brownstown, MI 734/789-1196
Mark
Your newsletters are on the way. I’ve included your phone number for builders in your area that may want to get in touch with you regarding the 10′ shear and brake. ~Bob
This is a combined list of mail Q&A from the 1995 Beartracks issues.
Dear Bob,
You have mentioned that you have the drawings for the wings of the BEARHAWK ready and had sent some out to builders in the U.S., at first I thought that I would leave it until you had the fuselage drawings ready as well, but on second thought I too would like a set to study and perhaps organize materials and you could forward the remaining drawings later. Bob, I have a few questions which I may need to give our Civil Aviation Authority some answers to when talking to them about the BEARHAWK.
Regards and best wishes.
Ray Thurston – Blenheim – New Zealand
Ray,
I sent your wing drawing by air post on Jan. 19, 1995. Please mark in on drawing #1 your serial number 005. Listed below are answers to most of you questions:
I hope that answers most of your questions and please stay in touch.
Bob
Enclosed please find a check for the second half of the BEARHAWK plans. As for my progress, I do not plan on starting until June. I have however, spent considerable time studying the first half of the plans. This has naturally generated several questions which I would greatly appreciate getting your input on.
Gordon Champion – Deep River – Ct. – serial #004
Gordon,
Grain is determined by the direction of the printing on the sheet aluminum; however, grain orientation is not a problem while your aircraft is under construction. Stress levels are within limits for either direction. Be sure to use proper bend radii to insure crack free parts.
As for my preferred welding technique I use gas welding (Oxy. – Acetylene), Tig should be OK as well.
The article you mention has raised concern with other builders also. I am recommending that you stick with mild steel welding rod. Airplanes built with 4130 tubing have used mild steel welding rod for years with almost perfect results. Alloy rod can be a big problem with cracking and brittle failure.
I hope that answers you questions. Let me know when you start construction.
Bob
The remainder of the Bearhawk drawings arrived so I have now worked out the quantities for the 4130 and other pieces on the fuselage, and have been in touch with Dillsburg Aeroplane Works.
I have ordered all the aluminum from Airparts in Kansas and that is due here in a container ship later on this month.
Meantime, I have constructed a long level work table the same as I had when I built my Tailwind, it is somewhat longer at 20′. I have also located a pair of Lift Struts, something I thought would not be available here.
Following your instructions in the newsletter I have made up a rib former and made up an end rib with some scrap to check it out complete with lightening holes, the wooden tool for flanging worked perfectly. I have a pair of fluting pliers which I made some years ago, everything else I need I either have or can obtain the use of.
I am retired so I have plenty of time, fortunately my wife likes gardening so that lets me off the hook there, although I do help by cutting lawns etc., perhaps I am a little spoilt, but it’s a nice setup. I don’t know if I told you but I was a mechanical engineer all my life and have had good experience with welding, machining and sheet metal work but have never had anything to do with aircraft sheet metal.
A few questions I want to ask you as you are a qualified in aircraft engineering.
When I built the Tailwind I constructed the the fuselage sides on the table, then stood them up in a jig and tackwelded in all the braces and crosspieces. I get the impression from your plans that you made up the top and the bottom and then fitted the side pieces, it probably doesn’t matter either way but as you are well into designing and building your methods would be useful to know.
I used oxy-acetylene with the Tailwind, I had thought of using a MIG welder this time and normalizing the welds after, what are your thoughts? Another question I have is regarding the weight and balance calculations, drawing No. 1 gives the C of G limitations also gross and empty weights etc., could you give me the length of arm for the engine, fuel, front and rear passengers and luggage if a locker were fitted beyond the rear seat I would like to know what numbers you used and when you weighed the aircraft what weights were on the mains and on the tailwheel. Could you give me your engine weight, the only Lycoming weights I can find give it at 256-265 lb. and I am unsure if this includes the mags. I note that you do not have an alternator or starter, but you have a constant speed prop, I believe they are quite chunky.
Looking at a Lycoming I0-540, they seem to weigh about 400 lb., once again I am unsure what this includes, so adding on a constant speed prop could put the total weight up to 500 lb., so is the C of G still within limits with this weight?
Regarding wing construction, there seems to be different ideas on attaching the skin, do you favour mounting the assembled spars and ribs on a vertical stand for skinning or packed up level on a flat surface?
Some of these things you may cover in future newsletters, so let me know.
Regards and Best Wishes, RAY THURSTON – NEW ZEALAND
DearRay,
We just got back from a great trip to SUN N’FUN with the BEARHAWK (1400mi.), plus another trip delivering a Lycoming engine to the Northeastern USA (1100 mi.). That’s a total of 160 hrs. on the BEARHAWK now. Good to read that you are a B.S.M.E. and past builder of a Tailwind.
Regarding the questions in your letter of April 1. 1995:
1. I built the fuselage as per plans due to the rounded nature of the sides of the fuselage. It is best to build the top and bottom frames, then jig in place and tack and weld the sides. This system seems to work best. This method will be covered in an upcoming issue of BEAR-TRACKS.
2. We use only OXY-ACETYLENE. MIG welding would not be my recommendation.
3. The length of engine arm will vary with engine used. Distance from wing leading edge to engine prop flange is approximately 56 inches. We are planing a complete weight and balance write-up in the near future. You can scale drawing #1, and reference construction drawings for other information.
| Prototype: | Mains = 1064 | Tail = 78 |
| Arm = -3.75 | Arm = + 195 |
4. The list of engines in the first newsletter should fit the C. of G. limits. The prototype 0-360 weighs 293 lb. dry (Dry is with mags and fuel system – carb or injection and without a starter or alternator). The heavier models (Lyc. 0-540) (396 lb. w/starter and alternator) will require battery mounting in the rear of the fuselage.
Sincerely,
Bob
I enjoyed talking with you at Oshkosh very much. You have a super design so I am enclosing a check for $200 for a set of plans. I think I will go with the Ford V6 engine as I can’t afford to start development work on a V8 right now. The V6 appears to be a proven powerplant and it is economical and well suited to the Bearhawk airframe.
At this time I do have a few questions for you:
1. Do you recommend that I only tack weld the sides and join them together before finish welding all, or do I finish each side while it is flat on the bench and join the finished sides together?
2. Can I use used 180 struts or should I buy new ones?
3. What parts can be purchased for the airframe that would speed up the assembly?
4. What used parts cart be substituted for new to keep the cost down?
Thanks again for a great design!
Mike Holcomb
Mike,
Your Bearhawk plans are on the way!! I hope you enjoy building the Bearhawk as much as I know you will enjoy flying it. Regarding your questions:
1. You will only need to tack weld the top and bottom of the fuselage separate, then join the two halves together by tack welding in the side tubes. The Bearhawk is different from
most other plans-built projects as you construct the top & bottom of the fuselage first and then tack weld in the side tubes. Look for more details in upcoming issues of BEAR-TRACKS.
2. You may use used 180 struts with broken ends as you will be installing your own end fittings anyway.
3. As this is a plans-built you will be building most of the parts. You may be able to ‘farm-out’ some of the work. Keep an eye on our suppliers’ section for possible sources.
4. There are a lot of used parts you can use in your Bearhawk to keep cost down. Instruments, wheels & brakes, hardware, etc. Again, look for a write-up on keeping cost low in an upcoming issue.
Best Wishes – Bob
Good news! BEARHAWK 009 is underway, with my first order for aluminum sheet for the ribs placed today from Dillsburg! Meanwhile I have been busy for two weeks building the assembly table, buying some used tools (metal band saw, floor drill press, welding clamps, air shears, bench grinder, acetylene welder) and studying the plans. My “airplane factory” is now set up on our screened back porch, once unused, with all tools under lock and key, good light and ceiling fans overhead (this is Florida, don’t forget). I’m also awaiting arrival of the four Tony Bingelis books from EAA (the fourth one is Engines). Until the aluminum arrives, I’ll be working on the rib form block, marking took and fluting pliers. I’m very excited and look forward now to each few hours I’ll get to work on the BEARHAWK. Beth is being a good sport even though she thinks I’m crazy and has to explain that I don’t even know how to fly. But not for long!
Below is a small idea that has worked out very well in case you want to pass it along. Thanks for making this dream possible with such a fine and affordable airplane. Hope you had a great time at Oshkosh, with lots of admiring interest in the BARROWS BEARHAWK.
Roy Nash
I am making up another order for raw material and I thought I would order a windshield, not that I will need it for sometime, but with freight cost to New Zealand, it pays to get a reasonable amount of material when making an order. Can you give me the suggested model of the Cessna 170 windshield I need. I also need the approximate lengths of control cable required for rudder, elevator, ailerons and trim.
There was also the matter of an increase to the VNE. I would like to have it increased to about 185 mph, your comment was about the prototype wings which were skinned with .020″ and the drawings were showing .025″ and that this would probably be OK, if this correct could you make the higher VNE official? I suppose when you have fitted the new wings to the Bearhawk you will be testing this aspect.
My final question is in relation to the wing to fuselage spar plates, do you drill and ream if required the 3/8″ and 5/16″ bolt holes out to full size at the time of assembly onto the spars or do you pilot drill only at that stage?
Regards,
Ray Thurston – New Zealand
Dear Ray,
Always good to hear from you. I just read an interesting article in the September ’95 issue of PRIVATE PILOT about flying the South Island of New Zealand. I must say I was very impressed. I think the Bearhawk will be right at home in your area! Regarding your questions:
The best looking and fitting windshield for the Bearhawk I have found is the Cessna 170B model made by L.P. Aero Plastic. The part number is #312 or #312.187 The 312 is 1/8″ thick the 312.187 is 3/16″ thick. 3/16″ would be best if you want a 185 VNE. Bearhawk.tips 2015 Note: LP now carries a Bearhawk-specific windshield that is a pre-trimmmed Cessna 170 model that will save considerable time
I will do the testing for the 185 VNE when the new wings are installed.
Control cable needed is 150 ft. of 1/8″ (7×19) and 30 ft. of 1/16″ (7×7). Scale your drawings for individual lengths needed, and leave a little extra for fitting on assembly.
When fitting the wings, I used a smaller 3/16″ pilot holes in the fuselage fittings and wing root fittings, then drilled to size on assembly.
Best Wishes – Bob