Bearhawk Aircraft Bearhawk Tailwheels LLC Eric Newton's Builder Manuals Bearhawk Plans Bearhawk Store

Announcement

Collapse
No announcement yet.

My unique mission and why the BH seems to fit

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • My unique mission and why the BH seems to fit

    I need a plane to make a 480 NM XC trip once a month for the coming 4-5 years or so. It needs to be a 4 place as my wife and 10 year old daughter will be with a good part of the time.

    My goal for this was to make the trip in under 4 hours and 30 gallons of Mogas or less. I have considered everything from Mooney's and Bonanza's to RV-10 and Velocity or BD-4C

    What really tipped the scales for the BH 4 place was that in 4-5 years I will be moving back home to MN from Indiana where I work now and I want to be able to convert the aircraft that I own to a float plane. Specifically on Full Lotus floats for year round use from our lake place up there.

    The BH seems like such a good compromise of cruise speed , STOL , efficiency , solid construction , price and versatility. I have been obsessing over every plane I could read about and I am not sure another EAB can do what the BH does.

    One thing I have not read about here that I am planning on is the use of the Viking 200 turbo or possibly the Aeromomentum 2.0T. I think this is the perfect engine type for this platform. The 1.5 liter honda is rock solid. 220 HP available for the first 20-30 seconds of flight. A solid 100lbs lighter then an o-540 and the ability to go up to 12k feet for XC cruise and burn 8-9 gph at hopefully 160 MPH TAS or more if the Bravo proves to be even more efficient.

    Either way I will be deciding on a kit in the next coming months and ordering this spring to start the build. I plan to have my PPL finished in 12 months and I'd like to finish the QB in about 12 months possibly employing some builder assist along the way if I can find a competent builder somewhat local.

    One thing that concerned me with some of the planes I was looking at was the lack of an active builder community....that is not the case the the BH and I look forward to contributing and asking lots of questions here.

    Ben

  • #2
    Hi Ben and welcome! Should we provide feedback on your ideas? We love being opinionated.

    Comment


    • #3
      Opinionated?? Ooohhhh! Ooohhh! (That's the sound of me raising my hand!)

      Bill

      Comment


      • #4
        Welcome Ben.

        I've never been one to raise my hand. The Bearhawk is indeed a fantastic airplane and will likely suite your described mission. I think it is worth checking out the Dream Aircraft Tundra which is also a fine airplane. Think extra hard about the auto conversion engines. I really REALLY wanted to install one but for various reasons I didn't. You'll be moving to MN in 4-5 year at which point you monthly commute will end? So, that will be right about the time you finish your build

        There are some good guys on this forum that can offer some good advise; it takes some time but you'll figure out who they are. I'm probably not one of them
        Scratch Built 4-place Bearhawk. Continental IO-360, 88" C203 McCauley prop.

        Comment


        • Wmilbauer
          Wmilbauer commented
          Editing a comment
          I agree with whee look hard at the tundra if you want to complete in a year

      • #5
        Of course any and all opinions are welcome and I know that I will certainly get some colorful responses to my plan to use a motor platform that originated as an auto.

        Comment


        • #6
          Originally posted by whee View Post
          Welcome Ben.

          I've never been one to raise my hand. The Bearhawk is indeed a fantastic airplane and will likely suite your described mission. I think it is worth checking out the Dream Aircraft Tundra which is also a fine airplane. Think extra hard about the auto conversion engines. I really REALLY wanted to install one but for various reasons I didn't. You'll be moving to MN in 4-5 year at which point you monthly commute will end? So, that will be right about the time you finish your build

          There are some good guys on this forum that can offer some good advise; it takes some time but you'll figure out who they are. I'm probably not one of them
          I looked at the Tundra and I'll dig a little deeper on it. Seems the bearhawk just checked every box a little better then the Tundra. Normally I'd agree with your assessment of my timeframe for completion :lol: but in this circumstance I have an empty 3 stall garage , significant motivation to finish a plane so I can fly home more often , and I average about 16 days off per month of which I would spend significant time working in the garage on the plane......so maybe I can get it done in a year if I punch out 12-1500 hours in a year.

          On the engine , I should state that I hate antiquated technology. Air cooled carb fed large cube motors are 100 year old tech. I dont think I would ever consider flying anything that had a carb on it. I cant make a chainsaw or weedwhacker run right but I have no problem building and tuning 300HP turbo snowmobiles and my last car made over 630HP at the wheels on pump gas with a 2.3 liter motor.

          Almost all of the issues with auto conversions seem to stem from poorly engineered and implemented FWF work......I wont have any of that !!!!!!!!111

          Flame away fellas lolz

          Comment


          • #7
            No flames coming from me. Doing what you want is what EAB aircraft is all about. It will be nice to have a fellow sled head around...though I keep to NA sleds and dazzle the boost riders with my superior riding slills🤣 Not.

            I feel much the same when it comes to antiquated aircraft motors but you can't really compare your 630hp turbo motor that only has to make that power for a second on the dyno or the 1/4mi to a engine that makes rated power for hours and hours with no power changes. Still, I'd love to see you do it.

            Pretty much everyone has told me I'm making a mistake by installing my chosen engine in my BH but I'm doing it anyways. It's fuel injected and I've updated it with electronic ignition, and a couple other minor modern things that should bring it into the 1980s...

            One of the things that really drew me away was the lack of properly engineered PSRUs and that very few have provisions for a hydraulic constant speed prop. The units that look good on paper, I have no idea how they are in real life, and ridiculously expensive. I've overhauled my Continental engine for thousands less than the cost of a PSRU. If I could have built an LS engine and purchased a PRSU that was properly engineered and had provisions for a hydraulic constant speed prop for $10k I would have done it...I think.
            Scratch Built 4-place Bearhawk. Continental IO-360, 88" C203 McCauley prop.

            Comment


            • #8
              My first build had a 'non standard' engine. I put a Continental IO520 in a plane designed for Lycoming 360's. Nothing terribly radical and still an aircraft power plant. That single decision added AT LEAST 18 months to the build! Granted, I was working full time and had two small children.
              Auto conversions are a whole different animal and would easily be the subject of a very interesting thread! Whee hit some of the highlights, but there's so much to that conversation to add.

              Bill

              Comment


              • #9
                Originally posted by whee View Post
                No flames coming from me. Doing what you want is what EAB aircraft is all about. It will be nice to have a fellow sled head around...though I keep to NA sleds and dazzle the boost riders with my superior riding slills🤣 Not.

                I feel much the same when it comes to antiquated aircraft motors but you can't really compare your 630hp turbo motor that only has to make that power for a second on the dyno or the 1/4mi to a engine that makes rated power for hours and hours with no power changes. Still, I'd love to see you do it.

                Pretty much everyone has told me I'm making a mistake by installing my chosen engine in my BH but I'm doing it anyways. It's fuel injected and I've updated it with electronic ignition, and a couple other minor modern things that should bring it into the 1980s...

                One of the things that really drew me away was the lack of properly engineered PSRUs and that very few have provisions for a hydraulic constant speed prop. The units that look good on paper, I have no idea how they are in real life, and ridiculously expensive. I've overhauled my Continental engine for thousands less than the cost of a PSRU. If I could have built an LS engine and purchased a PRSU that was properly engineered and had provisions for a hydraulic constant speed prop for $10k I would have done it...I think.
                Fellow sledder....nice. Electronic ignition and fuel injection make the aircraft motors more acceptable and if I do end up with an O-540 it would have EI and an SDS standalone driving it. The other issue I have is with the cost of these motors. I understand part of the issue is volume sales but you can buy 7 or 8 LS1s brand new for what one new underachieving Lycoming costs. That just strikes a chord with me that I find totally unacceptable. A good part of that is due to the bloated idiocy of the FAA and certified costs associated with their regulation

                I see the Conti vs Lycosaur issue as merely a Ford vs Chevy thing. As far as PSRU's I think they are easily able to be engineered right if a company took the time to do it. Look at yamaha apex motors. They have gear reduction and that unit will take 500HP and dead hook launches off the ice. Same thing with the Diamond Drive on the turbo cats. 500HP all day long. The hydraulic CS prop is an issue but there are some very nice electric variable pitch setups and that is the way I will go. MT or Airmaster etc etc. Being an electrician I am much more comfy with those vs the hydraulic ones any way lol

                Which Conti did you go with? Did you buy it as a functional core and do a complete overhaul?

                Comment


                • #10
                  Originally posted by Bdflies View Post
                  My first build had a 'non standard' engine. I put a Continental IO520 in a plane designed for Lycoming 360's. Nothing terribly radical and still an aircraft power plant. That single decision added AT LEAST 18 months to the build! Granted, I was working full time and had two small children.
                  Auto conversions are a whole different animal and would easily be the subject of a very interesting thread! Whee hit some of the highlights, but there's so much to that conversation to add.

                  Bill
                  If you're interested I'd encourage you to take a look into what Viking engines is doing with the 1.5 Liter honda motor. Direct Injection with a mechanical high pressure pump. The most precise fuel control available in any gas motor. Turbo available and in HP ranges from 110 to over 200HP. Compact and lightweight package that will be bullet proof if installed correctly.

                  Also another company that has my attention is Aeromomentum and they are using Suzuki G series engines. Extremely reliable and parts are mass produced all over the world and cheap. The key is in proper installation and design of the FWF package. Redundancy in the simple items like Lithium batteries and fuel pumps etc. The rest I wouldn't have an issue with.

                  No carb icing , no vapor lock , no fighting uneven cylinder temps....super fuel efficient etc etc.

                  This is the way I'm leaning but obviously I will be open minded right up until the day I cut the check

                  Comment


                  • #11
                    Originally posted by f7ben View Post
                    As far as PSRU's I think they are easily able to be engineered right if a company took the time to do it. Look at yamaha apex motors. They have gear reduction and that unit will take 500HP and dead hook launches off the ice. Same thing with the Diamond Drive on the turbo cats. 500HP all day long.
                    Not trying to discourage you from doing what you want to do – I'm all for the "experimental" side of EAB aircraft. But I think you're seriously under-estimating the challenge of developing a "good" PRSU design. The gear reduction units you describe above only have to handle the axial loads involved with rotating the gears. The torsional loads are carried by the frames, axles, and/or other suspension members – whether you're driving wheels or tracks. By contrast, an aviation PRSU has to be able to handle the axial load of turning a prop WHILE also supporting the thrust load applied perpendicular to that axis of rotation, and the gyroscopic loads imposed by the propeller – loads imposed at the end of the prop shaft by banking, pitching, and turning. The engineering problem is vastly more complex, and hundreds of thousands (perhaps millions?) of dollars have been spent trying to successfully accomplish this goal. There have been literally dozens of PRSU manufacturers that have come on the scene claiming that they had finally "figured it out" and "out-engineered" all the others that came before, and then gone out of business shortly after either failing to deliver anything to the marketplace, or perhaps selling a few of their "magic" PRSUs that blew up under load and either killed people or got them hurt. There have been darn few who have truly succeeded.

                    One MAJOR exception to this is Rotax, who have done a stellar job, albeit with PRSUs on engines of 80-115 HP thus far... Viking may or may not be another success story - to me, it's very difficult to determine if they have "succeeded" or not... On the positive side, they've been around for a few years, and have had some successful implementations. But I'm a bit concerned that they seem to always be offering the "next version" that hasn't shipped yet... Frankly, I'd LOVE to see one of the auto-conversion companies succeed in delivering a reliable engine/PRSU that is both economical to operate, and affordable to purchase and maintain. A Viking engine in an airplane designed for the much heavier Lycoming/Continental engines? I would think that an airframe originally designed for a smaller, lighter engine (say something like the Zenith Cruzer they talk so much about on their web site) would appear to be a better fit for the Viking, since it would presumably minimize the W&B issues. A Patrol powered by the Viking 200 turbo engine might be do-able, but I suspect the engine mount would probably have to be extended considerably to bring the center of gravity back into the desired range... But then you'd still have to deal with the effects of the gyroscopic loads way out on the extended nose, and how those would effect not only your flight characteristics, but the PRSU itself.

                    You said "The key is in proper installation and design of the FWF package," and that is dead-on accurate. The issue is that it's a LOT more challenging that you appear to believe. But like I said, I truly hope that someone does crack that nut successfully, and usher in an era of modern engines for our EAB aircraft.
                    Jim Parker
                    Farmersville, TX (NE of Dallas)
                    RANS S-6ES (E-LSA) with Rotax 912ULS (100 HP)

                    Comment


                    • #12
                      I purchased an O-320 for my Patrol project for the simple reason that I am getting too old to spend another few years to emphasize the "E" in EAA. However I find it fascinating to keep up with those who have a few decades left in life to try other non-traditional things when powering their aircraft.

                      I find that a bunch of guys who power their aircraft with Mazda rotary engines have some very interesting ongoing projects. You might be interested in their experimental PSRU designs which use the planetary gears from a Ford truck transmission. For the Mazda they use various gears that give them ratios in the range of 2.8:1 to 3.2:1, depending on how fast they want to run their engines. Their current PSRU models go around 40# and can handle several hundred HP.

                      There was a presentation made at OSH last month by a Paul Lamar which detailed their attempt to beat the current Time-To-Climb record to 10,000' MSL, currently held by an old military Bearcat I believe. They have a Mazda puting our something like 600HP and anticipate a climb rate in excess of 6000 ft./min. from their 1000# aircraft.

                      The Mazda rotary engine group works not only on new PSRU designs, but tuned induction, carburetors, EFI, CCD ignition, cooling, and exhaust systems. It requires people that not only have vision for the future but a lot of time more than money.

                      I keep myself posted on what these guys are doing by subscribing to their newsletter.

                      Check out http://www.rotaryeng.net



                      Comment


                      • #13
                        Hi Ben,
                        The first thing that comes to mind when I read your plans is that they are very ambitious, and that your expectations are a little optimistic. Especially your expectations of build time and utility upon completion.
                        A first-time builder who completes a Bearhawk in a year and 1200-1500 hours of build time is an extreme outlier. Someone who does that is the one who builds from a quick-build kit and does not deviate at all from the basic configuration. He also spends extra money to buy bolt-on options whenever they are available, and does not spend time to customize or fabricate custom parts, or to scratch his head figuring anything out. Building in that time frame definitely does not involve a less-proven engine installation. A more realistic time frame for a first-time builder who does not significantly deviate is 1500-2500 hours, and a more realistic number for someone who installs an auto engine is 3000-5000. Sometimes we look at those numbers and thing "I'm smarter than the average bear, I can totally be on the short side of those hours." I've spent lots of time with lots of Bearhawk folks, and found that at least for me, this was definitely not the case.
                        As Jim says, many people have come before and said that auto engines should make so much more sense than the antiquated airplane engine technology. But yet, as Jim also says, the devil is in the details. Car manufactures have established spectacular reliability by investing decades of expensive R&D to the entire vehicle, not just to the engine. Making a car engine work in an airplane requires plucking one highly engineered part out of a highly engineered vehicle, and then highly engineering all of the dots that connect it to the airplane. For example, the engine mount, exhaust system, fuel delivery, PSRU (with the challenges that Jim points out), fuel metering, cooling system, cowling, and parameter monitoring. And all of this must not just be accomplished so that it works at all, it must work with extraordinary reliability, weigh as little as possible, and each component must fail in a way that it delivers an acceptable level of risk upon failure.
                        I'm of the opinion that traditional aero engines, while they seem antiquated and simple, are actually not very antiquated, and not at all simple. Get a copy of the Sky Ranch Engineering Manual by John Schwaner (Amazon link) and read the whole thing. Read Kevin Cameron's books about the complexity of delivering the "shoulds" into actual performance. He writes a column in Cycle World magazine that is mostly about motorcycle engines, but he also talks about airplane engines, and talks alot about the kind of R&D it takes to realize that theories don't always translate into the expected performance. Reading his work changed the way I understood how engines work, and I haven't read but a small percentage of it.

                        To summarize, there have been Bearhawk builders who have successfully integrated auto engines. I know of one that has stuck with it (though there may be another) and when asked if he'd do it the same way next time, he said no. I have not yet met anyone who would recommend the auto engine to a future builder. There may be someone, but if there is, I have not yet heard from him.

                        Aside from the auto engine issue, which has also been further discussed in the archives, I'm afraid that you might also be over-estimating the utility of travel in a GA airplane. Have you started the cross-country part of your training yet? Taking a trip that long, that regularly, in a place that far north, is a big deal. If you are planning to fly VFR only, taking a 480nm trip is an adventure every time. By that I mean that you never really know how it is going to turn out until you do it, and if you have a rigid timeline to complete the trip, you'll either be regularly lucky or regularly disappointed. If it is time to go and the weather is bad, are you able to wait for a few days for it to get better? If you are planning to go IFR, how will you handle avoiding icing conditions in the months that aren't the summer, and the convective activity otherwise? Traveling in a light single engine plane is not like driving a car at 150 knots, combining the best of car travel and the best of air travel. Each mode comes with its own advantages and disadvantages. When someone travels by GA for fun, he usually has fun. When he travels by GA (talking about light singles) for utility, he finds that determination is not something that can overcome mother nature. (to that point, everyone should read "Finding Carla" by Ross Nixon Amazon link )

                        I know this is a lot of negativity, and it isn't fun to have someone pee on your corn flakes. It's just that when I read your original post, I see red flags that indicate your expectations might not match your plans. Sort of like having a friend say "I'm headed to Florida!" then watching him pull onto the I40 onramp.

                        Comment


                        • #14
                          Originally posted by JimParker256 View Post

                          Not trying to discourage you from doing what you want to do – I'm all for the "experimental" side of EAB aircraft. But I think you're seriously under-estimating the challenge of developing a "good" PRSU design. The gear reduction units you describe above only have to handle the axial loads involved with rotating the gears. The torsional loads are carried by the frames, axles, and/or other suspension members – whether you're driving wheels or tracks. By contrast, an aviation PRSU has to be able to handle the axial load of turning a prop WHILE also supporting the thrust load applied perpendicular to that axis of rotation, and the gyroscopic loads imposed by the propeller – loads imposed at the end of the prop shaft by banking, pitching, and turning. The engineering problem is vastly more complex, and hundreds of thousands (perhaps millions?) of dollars have been spent trying to successfully accomplish this goal. There have been literally dozens of PRSU manufacturers that have come on the scene claiming that they had finally "figured it out" and "out-engineered" all the others that came before, and then gone out of business shortly after either failing to deliver anything to the marketplace, or perhaps selling a few of their "magic" PRSUs that blew up under load and either killed people or got them hurt. There have been darn few who have truly succeeded.

                          One MAJOR exception to this is Rotax, who have done a stellar job, albeit with PRSUs on engines of 80-115 HP thus far... Viking may or may not be another success story - to me, it's very difficult to determine if they have "succeeded" or not... On the positive side, they've been around for a few years, and have had some successful implementations. But I'm a bit concerned that they seem to always be offering the "next version" that hasn't shipped yet... Frankly, I'd LOVE to see one of the auto-conversion companies succeed in delivering a reliable engine/PRSU that is both economical to operate, and affordable to purchase and maintain. A Viking engine in an airplane designed for the much heavier Lycoming/Continental engines? I would think that an airframe originally designed for a smaller, lighter engine (say something like the Zenith Cruzer they talk so much about on their web site) would appear to be a better fit for the Viking, since it would presumably minimize the W&B issues. A Patrol powered by the Viking 200 turbo engine might be do-able, but I suspect the engine mount would probably have to be extended considerably to bring the center of gravity back into the desired range... But then you'd still have to deal with the effects of the gyroscopic loads way out on the extended nose, and how those would effect not only your flight characteristics, but the PRSU itself.

                          You said "The key is in proper installation and design of the FWF package," and that is dead-on accurate. The issue is that it's a LOT more challenging that you appear to believe. But like I said, I truly hope that someone does crack that nut successfully, and usher in an era of modern engines for our EAB aircraft.
                          Thank you very much for taking the time to type that out. Certainly I'm not and engineer and have limited understanding of the loads placed on PSRU's in comparison to other gear reduction type setups. From my reading it seemed that there were plenty of planes flying with PSRU's but I guess I wasnt digging in the direction that would have revealed all the failed projects and promises. I'm a complete rookie here and I like to dream big. Its information like you just delivered that will temper my ambition and make my expectations realistic and shape the decision I make into ones that hopefully succeed. Thanks again

                          On the W&B aspect of the viking or other auto's like it. I think the FWF would weigh in around an O-320 and from what I read about the bearhawk that should work correct?

                          Comment


                          • #15
                            Originally posted by bergy View Post
                            I purchased an O-320 for my Patrol project for the simple reason that I am getting too old to spend another few years to emphasize the "E" in EAA. However I find it fascinating to keep up with those who have a few decades left in life to try other non-traditional things when powering their aircraft.

                            I find that a bunch of guys who power their aircraft with Mazda rotary engines have some very interesting ongoing projects. You might be interested in their experimental PSRU designs which use the planetary gears from a Ford truck transmission. For the Mazda they use various gears that give them ratios in the range of 2.8:1 to 3.2:1, depending on how fast they want to run their engines. Their current PSRU models go around 40# and can handle several hundred HP.

                            There was a presentation made at OSH last month by a Paul Lamar which detailed their attempt to beat the current Time-To-Climb record to 10,000' MSL, currently held by an old military Bearcat I believe. They have a Mazda puting our something like 600HP and anticipate a climb rate in excess of 6000 ft./min. from their 1000# aircraft.

                            The Mazda rotary engine group works not only on new PSRU designs, but tuned induction, carburetors, EFI, CCD ignition, cooling, and exhaust systems. It requires people that not only have vision for the future but a lot of time more than money.

                            I keep myself posted on what these guys are doing by subscribing to their newsletter.

                            Check out http://www.rotaryeng.net


                            Thanks , there is a pretty dedicated community in several sports when it comes to the mazda rotary. I dont have any experience with them and experience is why I am leaning towards an inline 4cylinder. I am familiar with them and their various setups. I've done plenty of DOHC topend work and quite a bit of turbo setup and its just something I am familiar and comfortable with

                            Comment

                            Working...
                            X