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Grab a coffee as this my take a minute. I have been procrastinating for sometime and was reluctant to post this. A health kick in the head has pushed me with getting on asking for some wisdom. I know that there will be strong opinions and a critical eye is always good. We are 3 partners that successfully completed a scratch built a 4 seat Bearhawk that is flying in its 4th year with about 80 hours on the air frame. We are all at the age where we are thinking it is time to move on and let someone else enjoy a great airplane. We have no idea of the current value of a good flying Bearhawk in particular the one we built. We thought a good place to ask was the forum to help determine a reasonable value for our Bearhawk.
It is a quality airplane that was constructed to high standard to be a good safe well built utility airplane to serve our purpose. It is not built to Oshkosh competition level but is intended to be a well done flying pick up. There is nothing better than flying on a warm March day to a remote lake on skis, coast up to a good fishing spot, open the barn doors and unload fishing gear, power auger and lawn chairs to enjoy a great day. The lake rarely sees life and the trout average 5 – 9 lbs. Catch a limit and pop over the trees to another hot lake to take some nice walleyes. It will be hard to give that up.
The Bearhawk flies great and has excellent power. The engine is a 6 cylinder fuel injected Continental IO-360 that has about 950 hour SMOH. The propeller is a McCauley 82” constant speed propeller. It is registered at 2700 lbs for floats with the condition that it does not do ground landings over 2500 lbs. Its empty weight with tundra tires is 1470 lbs.
It flies at 120 mph at 2250 rpm economy cruise on tundra tires or skis. The airplane averages 8 – 8.5 gph. It stalls with power between 38-42mph and clean around 49mph. It will fly level at 45mph. The airplane seems to take to flight right after the tail pops up. On its maiden flight the test pilot used the field as it would not stop flying. The airplane on skis is airborne in 7 seconds. We have not done a climb test since the gross load but with a normal load is well in excess of the 1200 fpm and it really climbs which my be in part due to the modifications.
The airplane is set up to operate on wheels, skis and floats. Currently flies with 26” tires and a set of 2500 lb skis. It was built with the rear float attachments and fittings for the cable pulleys and guide tube for the rudder lift cable. It has a set of 2500 lb fiberglass floats with the gear legs and rigging. The floats have not been set up for the Bearhawk.
The air flow is efficient through the cowl and the engine so the engine runs cool. Normally a piece of card board is on the oil cooler to get oil to temperature. The nose bowl was a MC3A completely reconfigured to fit snug to provide a good up slope. My partner wanted the cowl underside to emulate the shape of an extreme STOL Mountain Goat aircraft. The theory was a clean steep slope underside could assist with climb out. The engine baffles were built to seal tight to the engine and cowl to be like a pressure cowl built to best emulate Zavaston’s principles.
The upgrades include a heavy wall tube inside the streamline tube on the shock gear legs. The rudder and brake pedals were moved 4 inches closer to the seat. The pedals work well for a short or tall person. The tail is a flying tail with one degree taken out of the tail with the ability to adjust one more degree. Wing skin extensions are installed to make close fitting gap seals between the flaps and ailerons. The fuselage follows the wing form from the windshield back without the characteristic Bearhawk hump. Right or wrong the thought was that if the fuselage between the wings carried the wing shape across the fuselage that it is like additional wing surface to assist lift. The fairing trailing edge at the fuselage is a diagonal for better aerodynamics. There are lift points hidden under the fairings and a separate a lift frame that attaches to the lift points. The plane is set up to use the lift frame to simplify change over. The flying club is a water base and a member brings a boom truck on change over day to lift the planes on or off floats. The tailwheel is a stinger tail wheel. A very small trim tab was installed on the left wing aileron to level the airplane in flight. The airplane flies straight for a long distance before needing any correction. A set of Hall Brothers vortex generators were installed across the wings and across the under side of the tail similar to Ron Jone’s Bearhawk. http://www.mykitlog.com/users/displa...ct=191&categor y=4906&log=137399&row=1
The interior is fabric and the seats are comfortable covered with an automotive grade fabric and foam. The airplane has the barn doors with an easy to remove rear seat. The instrumentation is a Dynon 180 with all EFIS feature that includes the complete EMS for a 6 cylinder Continental engine. The Dynon measures cylinder head and exhaust gas temperature for all 6 cylinders so it is possible to see the effects of fuel adjustments for optimum performance. It has a Garmin GTR220 radio and a transponder. The transponder is not in service as it needs its altitude to be calibrated with the Dynon. It has Aveo Ultra 3 in 1 navigation, position and strobe lights. The instrument panel is shaped like a Supercub with dropped corners with the thought that the pilot gets a better view of the ground on landing.
The engine is a fuel injected Continental IO-360 210 hp engine from a 337 Skymaster. The owner had more money than good sense. The engine mount is a Skymaster rear engine bed mount that was cleaned up and modified to fit with design changes by Bob Barrows. The exhaust is custom dual 3 into 1 dual headers with heat cuff mufflers built by Clint. The exhaust may add about 6 hp. The prop is a first run McCauley 2A34C203/90DCA-2 constant speed propeller that was purchased from an owner that replaced the propeller with a new unit. Q1 Aviation quoted $3600 to overhaul the propeller and reblade to 82”. Q1 overhauled the prop and we were invoiced about $3000 as the prop was in excellent condition. The 82” propeller length was the longest listed in the McAuley Propeller Application Guide on a Continental IO-360 engine. The propeller was in line with propellers on certified aircraft and works excellent with the IO-360.
The wings and fuselage were built straight and accurate. The jig pin holes in the ribs appear like one hole through all the ribs for the full length of the window. The main spar attach points were offset the 3/8 so that the ribs fit square to the spar. We pioneered the use of a double rib forms to bend the fuel tank bay ribs for a good fit and documented in the Beartracks. We made wood reinforcements for the tip of the nose ribs so that the nose skins can be pulled down tight to get the precise leading edge. That was documented for the Beartracks. The spars were set in the wing jig frames with a surveyor’s level. String lines with heavy weights were used to confirm the mainspar was holding straight and a second string line with a bead to set the ribs. The bead just cleared the jig holes and when the space was the same all around the bead then the rib was clamped in place. The fuselage is built dead straight. The tubes were coped to a tight fit before being tacked. Each cluster was preheated, TIG welded and immediate post heat then packed in insulation. The fuselage was put on the jig table to check for any misalignment. It was straight within a width of a pencil line. I think with using good building practices that the wings and fuselage is a quality that is on par with the factory quick build wings and fuselage or perhaps better.
Background:
We had one basic rule is that if anyone did not like anything that we would change it to everyone’s satisfaction. We took 12 years to complete and definitely have thousands of hours into the build. We worked 3 nights a week and took summers off. Then we retired and were working 3 full days a week. The irony is very little of that time was chatting and we all did separate tasks most of the time. If someone looked like they were not working Bob would find something for them to do. Definitely a proponent of the Quickbuild kits if one values the time building from scratch as time out of there life.
The engine was one of a pair that came out a Cessna 337. The Skymaster owner owned some aircraft maintenance centers with more money than sense. He bought the Skymaster then had his local shop repower the Skymaster with a pair Corvette conversion engines. The mechanics told us that both the engines were both in excellent condition. They pulled a couple cylinders on each engine to check their condition so we bought the engine with the lowest hours. They said the fuel injection system is a mechanical fuel that is simple and extremely reliable. Discovery Air fly and maintain several Skymasters and several Aero Commanders for forest fire spotter service. The mechanics have a long history with Skymaster engines. The mechanics all have been great in supporting us. Neil, one of the mechanics was interested in our project and said he would help. We sent the fuel pump and the fuel distribution manifold for overhaul. Neil overhauled the mags. Neil had a lot of experience and recommended the best practices with the engine installation. Neil does all the engine work as part of the annual inspections.
One partner Bob, is a certified Red Seal welder with decades of experience. I am as a certified mechanical and civil engineering tech with over 30 year of industrial experience with design, construction, maintenance, NDT, and 5 years of managing the company’s welding program. I have experience of surveying paper machine rolls for line and level to .006” or less and working with the trades to set other equipment to high tolerances. The third partner, Jim is a veteran first class stationary engineer.
Our Bearhawk is very well built as we went above and beyond all through its construction. A Lincoln 225 Precision TIG welder for the project and Bob studied best practices for welding 4130 chromoly. All the tubes were coped to be a snug fit. After the fuselage was completely welded it came off the rotisserie and was put on the jig table to check it’s alignment. The reference marks all were within a pencil width of the center.
A surveyor level was used to set the spar ends in the wing frames and used precision practices to keep the spars level and the ribs in alignment. The jig pin holes appear as one hole through all the ribs. We also submitted to Beartracks a method to temporary reinforce the nose rib tips and holding the ribs in place while skinning over the nose. The nose skin was snug to the rib for a perfect fit. We laid masking tape on the top side of the main ribs, marked the rivet rows and hole centers on the rib. We drilled the marked centers with a 1/16th bit. A level was used to hold a rib straight then a cordless Dremel with a rt angle drill head was used to drill out the 1/16” hole to the rivet size. The hole was drilled out to the rivet size from the underside to the rib then clecoed. This method avoided a rivet row on a flute and every rivet was dead center of the rib flange. It was easier way to put all the rivets precisely where they needed to be. Our team pioneered & documented for the Beartracks the forming of the fuel bay ribs with heat over parallel rib templates. We had the wings on the table to set the flaps and ailerons then we decided to extend the wing skins to form gap seals. We removed a rivet row and slid the aluminum extensions under the wing skin and re-riveted for a nice fit up.
I read a lot on experimental aviation, biggest down falls of home builders with fuel issues and cooling. I was a member of the EAA, subscribed to Kitplanes, subscribed to the Beartracks and a member of the Bearhawk forums. It was from Kitplanes that I learned of Zavaston’s pressure cowl cooling and his techniques. Many other sources on cooling and the effect on an airplane’s drag. We fit the baffles tight to the engine and cowl. The inlets were ducted for a clean air flow into the space over the engine. The exhaust headers are set up wide apart to provide a good clear path for cooling air to exit. The outlet at the firewall had the half tear drop was applied to assist in creating laminar from the boot cowl. The engine seemed to run too cool so the bottom half of the inlet duct was removed to create some turbulent air flow. A piece of cardboard covers a portion of the oil cooler. The gap between the nose bowl and spinner is tight and is about a 1/4”. The fit is close and works because the engine sits on a rigid bed mount.
We used both Russ Erb and Eric Newton’s manuals. The spar attach points were set with the offset as surveyed in & measured on the wing master pattern. We followed the old Bearhawk and new Bearhawk forums to see what the issues were and use the best practices.
The airplane past all three of its MD-RA inspection with no issues including the final which the inspector said did not happen often. The inspector said that we had a great airplane and that it was well built.
If you have read to the end it is appreciated.
Thank You
IMG_1185.jpg881 a.jpgIMG_1166.jpgFinal.jpgFinal 2.jpg
It is a quality airplane that was constructed to high standard to be a good safe well built utility airplane to serve our purpose. It is not built to Oshkosh competition level but is intended to be a well done flying pick up. There is nothing better than flying on a warm March day to a remote lake on skis, coast up to a good fishing spot, open the barn doors and unload fishing gear, power auger and lawn chairs to enjoy a great day. The lake rarely sees life and the trout average 5 – 9 lbs. Catch a limit and pop over the trees to another hot lake to take some nice walleyes. It will be hard to give that up.
The Bearhawk flies great and has excellent power. The engine is a 6 cylinder fuel injected Continental IO-360 that has about 950 hour SMOH. The propeller is a McCauley 82” constant speed propeller. It is registered at 2700 lbs for floats with the condition that it does not do ground landings over 2500 lbs. Its empty weight with tundra tires is 1470 lbs.
It flies at 120 mph at 2250 rpm economy cruise on tundra tires or skis. The airplane averages 8 – 8.5 gph. It stalls with power between 38-42mph and clean around 49mph. It will fly level at 45mph. The airplane seems to take to flight right after the tail pops up. On its maiden flight the test pilot used the field as it would not stop flying. The airplane on skis is airborne in 7 seconds. We have not done a climb test since the gross load but with a normal load is well in excess of the 1200 fpm and it really climbs which my be in part due to the modifications.
The airplane is set up to operate on wheels, skis and floats. Currently flies with 26” tires and a set of 2500 lb skis. It was built with the rear float attachments and fittings for the cable pulleys and guide tube for the rudder lift cable. It has a set of 2500 lb fiberglass floats with the gear legs and rigging. The floats have not been set up for the Bearhawk.
The air flow is efficient through the cowl and the engine so the engine runs cool. Normally a piece of card board is on the oil cooler to get oil to temperature. The nose bowl was a MC3A completely reconfigured to fit snug to provide a good up slope. My partner wanted the cowl underside to emulate the shape of an extreme STOL Mountain Goat aircraft. The theory was a clean steep slope underside could assist with climb out. The engine baffles were built to seal tight to the engine and cowl to be like a pressure cowl built to best emulate Zavaston’s principles.
The upgrades include a heavy wall tube inside the streamline tube on the shock gear legs. The rudder and brake pedals were moved 4 inches closer to the seat. The pedals work well for a short or tall person. The tail is a flying tail with one degree taken out of the tail with the ability to adjust one more degree. Wing skin extensions are installed to make close fitting gap seals between the flaps and ailerons. The fuselage follows the wing form from the windshield back without the characteristic Bearhawk hump. Right or wrong the thought was that if the fuselage between the wings carried the wing shape across the fuselage that it is like additional wing surface to assist lift. The fairing trailing edge at the fuselage is a diagonal for better aerodynamics. There are lift points hidden under the fairings and a separate a lift frame that attaches to the lift points. The plane is set up to use the lift frame to simplify change over. The flying club is a water base and a member brings a boom truck on change over day to lift the planes on or off floats. The tailwheel is a stinger tail wheel. A very small trim tab was installed on the left wing aileron to level the airplane in flight. The airplane flies straight for a long distance before needing any correction. A set of Hall Brothers vortex generators were installed across the wings and across the under side of the tail similar to Ron Jone’s Bearhawk. http://www.mykitlog.com/users/displa...ct=191&categor y=4906&log=137399&row=1
The interior is fabric and the seats are comfortable covered with an automotive grade fabric and foam. The airplane has the barn doors with an easy to remove rear seat. The instrumentation is a Dynon 180 with all EFIS feature that includes the complete EMS for a 6 cylinder Continental engine. The Dynon measures cylinder head and exhaust gas temperature for all 6 cylinders so it is possible to see the effects of fuel adjustments for optimum performance. It has a Garmin GTR220 radio and a transponder. The transponder is not in service as it needs its altitude to be calibrated with the Dynon. It has Aveo Ultra 3 in 1 navigation, position and strobe lights. The instrument panel is shaped like a Supercub with dropped corners with the thought that the pilot gets a better view of the ground on landing.
The engine is a fuel injected Continental IO-360 210 hp engine from a 337 Skymaster. The owner had more money than good sense. The engine mount is a Skymaster rear engine bed mount that was cleaned up and modified to fit with design changes by Bob Barrows. The exhaust is custom dual 3 into 1 dual headers with heat cuff mufflers built by Clint. The exhaust may add about 6 hp. The prop is a first run McCauley 2A34C203/90DCA-2 constant speed propeller that was purchased from an owner that replaced the propeller with a new unit. Q1 Aviation quoted $3600 to overhaul the propeller and reblade to 82”. Q1 overhauled the prop and we were invoiced about $3000 as the prop was in excellent condition. The 82” propeller length was the longest listed in the McAuley Propeller Application Guide on a Continental IO-360 engine. The propeller was in line with propellers on certified aircraft and works excellent with the IO-360.
The wings and fuselage were built straight and accurate. The jig pin holes in the ribs appear like one hole through all the ribs for the full length of the window. The main spar attach points were offset the 3/8 so that the ribs fit square to the spar. We pioneered the use of a double rib forms to bend the fuel tank bay ribs for a good fit and documented in the Beartracks. We made wood reinforcements for the tip of the nose ribs so that the nose skins can be pulled down tight to get the precise leading edge. That was documented for the Beartracks. The spars were set in the wing jig frames with a surveyor’s level. String lines with heavy weights were used to confirm the mainspar was holding straight and a second string line with a bead to set the ribs. The bead just cleared the jig holes and when the space was the same all around the bead then the rib was clamped in place. The fuselage is built dead straight. The tubes were coped to a tight fit before being tacked. Each cluster was preheated, TIG welded and immediate post heat then packed in insulation. The fuselage was put on the jig table to check for any misalignment. It was straight within a width of a pencil line. I think with using good building practices that the wings and fuselage is a quality that is on par with the factory quick build wings and fuselage or perhaps better.
Background:
We had one basic rule is that if anyone did not like anything that we would change it to everyone’s satisfaction. We took 12 years to complete and definitely have thousands of hours into the build. We worked 3 nights a week and took summers off. Then we retired and were working 3 full days a week. The irony is very little of that time was chatting and we all did separate tasks most of the time. If someone looked like they were not working Bob would find something for them to do. Definitely a proponent of the Quickbuild kits if one values the time building from scratch as time out of there life.
The engine was one of a pair that came out a Cessna 337. The Skymaster owner owned some aircraft maintenance centers with more money than sense. He bought the Skymaster then had his local shop repower the Skymaster with a pair Corvette conversion engines. The mechanics told us that both the engines were both in excellent condition. They pulled a couple cylinders on each engine to check their condition so we bought the engine with the lowest hours. They said the fuel injection system is a mechanical fuel that is simple and extremely reliable. Discovery Air fly and maintain several Skymasters and several Aero Commanders for forest fire spotter service. The mechanics have a long history with Skymaster engines. The mechanics all have been great in supporting us. Neil, one of the mechanics was interested in our project and said he would help. We sent the fuel pump and the fuel distribution manifold for overhaul. Neil overhauled the mags. Neil had a lot of experience and recommended the best practices with the engine installation. Neil does all the engine work as part of the annual inspections.
One partner Bob, is a certified Red Seal welder with decades of experience. I am as a certified mechanical and civil engineering tech with over 30 year of industrial experience with design, construction, maintenance, NDT, and 5 years of managing the company’s welding program. I have experience of surveying paper machine rolls for line and level to .006” or less and working with the trades to set other equipment to high tolerances. The third partner, Jim is a veteran first class stationary engineer.
Our Bearhawk is very well built as we went above and beyond all through its construction. A Lincoln 225 Precision TIG welder for the project and Bob studied best practices for welding 4130 chromoly. All the tubes were coped to be a snug fit. After the fuselage was completely welded it came off the rotisserie and was put on the jig table to check it’s alignment. The reference marks all were within a pencil width of the center.
A surveyor level was used to set the spar ends in the wing frames and used precision practices to keep the spars level and the ribs in alignment. The jig pin holes appear as one hole through all the ribs. We also submitted to Beartracks a method to temporary reinforce the nose rib tips and holding the ribs in place while skinning over the nose. The nose skin was snug to the rib for a perfect fit. We laid masking tape on the top side of the main ribs, marked the rivet rows and hole centers on the rib. We drilled the marked centers with a 1/16th bit. A level was used to hold a rib straight then a cordless Dremel with a rt angle drill head was used to drill out the 1/16” hole to the rivet size. The hole was drilled out to the rivet size from the underside to the rib then clecoed. This method avoided a rivet row on a flute and every rivet was dead center of the rib flange. It was easier way to put all the rivets precisely where they needed to be. Our team pioneered & documented for the Beartracks the forming of the fuel bay ribs with heat over parallel rib templates. We had the wings on the table to set the flaps and ailerons then we decided to extend the wing skins to form gap seals. We removed a rivet row and slid the aluminum extensions under the wing skin and re-riveted for a nice fit up.
I read a lot on experimental aviation, biggest down falls of home builders with fuel issues and cooling. I was a member of the EAA, subscribed to Kitplanes, subscribed to the Beartracks and a member of the Bearhawk forums. It was from Kitplanes that I learned of Zavaston’s pressure cowl cooling and his techniques. Many other sources on cooling and the effect on an airplane’s drag. We fit the baffles tight to the engine and cowl. The inlets were ducted for a clean air flow into the space over the engine. The exhaust headers are set up wide apart to provide a good clear path for cooling air to exit. The outlet at the firewall had the half tear drop was applied to assist in creating laminar from the boot cowl. The engine seemed to run too cool so the bottom half of the inlet duct was removed to create some turbulent air flow. A piece of cardboard covers a portion of the oil cooler. The gap between the nose bowl and spinner is tight and is about a 1/4”. The fit is close and works because the engine sits on a rigid bed mount.
We used both Russ Erb and Eric Newton’s manuals. The spar attach points were set with the offset as surveyed in & measured on the wing master pattern. We followed the old Bearhawk and new Bearhawk forums to see what the issues were and use the best practices.
The airplane past all three of its MD-RA inspection with no issues including the final which the inspector said did not happen often. The inspector said that we had a great airplane and that it was well built.
If you have read to the end it is appreciated.
Thank You
IMG_1185.jpg881 a.jpgIMG_1166.jpgFinal.jpgFinal 2.jpg
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