First Flight of George Huntington’s Bearhawk 4-Place, C-GSOI
George’s airplane is built from scratch (plans 493) over a period of 16 years. It is one of a set of four building friends, including Cam Lawrence whose first flight was last year, Ziggy Smolinski (#3) who should fly his next year, and a fourth that is too early to set a completion expectation. George’s first flight was on November 23rd, 2022. Insulation was added to the floor and sidewalls, and the cabin includes a tinted skylight plus windows in the lower front doors for landing gear viewing. Seats are covered in leather. The empty weight came in at 1532 pounds with a CG of 10.85 inches.
The engine is a Lycoming I0-540-C4B5 with a standard Bendix RSA type fuel injection system, E-Mag ignition system series 200-6XL, Air flow performance 110-degree intake elbow with K&N E-0995 air filter and custom housing with manually actuated alternate air. The exhaust is from Vetterman. The oil system includes a B&C Specialty oil filter adapter PN BC702, a CH48108 filter, and 9 row oil cooler. The propeller is a Hartzell HC-C2YK-1BF C/W with a polished spinner, Saber Manufacturing 4-inch prop extension, and MT-P860-5 governor. George installed electric cowl flaps by using a Ray Allen B6-11T actuator.
The electric system includes an Odyssey Powersafe Dry Cell Battery (SBS J-16) and a 12-volt main battery, charged by a B&C 460-H 60-amp alternator with 0706742 voltage regulator.
The panel is built around the Dynon Avionics SkyView Classic system with single PFD, dual com, Mode S transponder, ADSB, 2 place intercom, knob control, and 2-axis autopilot. He used the Dynon Remote magnetometer (SV-MAG-236) and also installed a Dynon EFIS SV-Bat-320 back up battery. There is an ipad flush-mounted in the panel, and also an, Airpath C2400 L4P wet compass. The ACK E-04 406 ELT is coupled to GPS so that it can send coordinates to search and rescue. Electric trim is driven by Ray Allen T12-10A servos, two for the elevator and one installed at the rudder.
Lighting comes from Aveo combination position/strobe lights, dual Aero-led Microsun landing lights, and interior 754 series Red/White LED lights for the cabin and panel.
The landing gear includes a Bob tailwheel fabricated from R&B drawing with 4” wheel and 10×3:50×4 tire, flat leaf spring, Cleveland 6” mainwheels with 8:00X6 tires and dual piston Cleveland brake calipers. It is also set up for Aero-Skii M2000 skis with a spring bungee, and EDO 2870 floats.
The fuel system features the Andair FS20-4 fuel selector and GAS375 Gascolator, Airflow Performance electric fuel boost pump PN 2090255, Princeton capacitance fuel probes for each tank, and positive vents mounted on bottom of wing just behind the strut (to defect any debris or rain while in flight). Wing-mounted fuel tanks are replaced with “wet wing” integral fuel tank system with a capacity of 257 liters (68 US gal).
The aircraft is covered with Stewarts Systems fabric system and painted with base Insignia White, Firethorn Red, Bahama Blue and Smoke grey striping, using a paint mask. Main entry doors were converted from original design to a single gull wing door opening to the wing lower surface with gas struts as hold open rods. There is a custom sliding window mechanism made by cutting slots into a plastic track.
The horizontal stab mounts were welded in place with the mounting bolt accessed from inside the fuselage and a removable metal cover was installed on the belly from the tailpost to the next station for easy access to the inside tail section. On the horizontal stab a wood spacer shaped to the airfoil shape was glued to the inboard rib and trimmed to minimize the space between the fuse and the stab so no fairing was required.
Elevator up and down position stop was modified by adding an internally threaded 4130 tube welded to the tailpost with an adjustable stop (bolt) which contacts the elevator bellcrank. Aileron travel limiting stops were added at the aileron bellcrank area by welding a 4130 tube to the compression strut and a using a stop bolt which contacts the bellcrank to provide aileron stops (photo above). Positive control stops are a Canadian regulatory requirement.
Hoerner style wing tips were fabricated using foam cut to shape and covered with two layers of carbon fiber. One layer of fiberglass mounted edges was built up using fiberglass to stiffen them up (3.5 lbs. each). George says, “First flight 1.5 hours, couple minor adjustments required, but WOW such a thrill.”
Photos:
Aileron bellcrank positive stops as required by Canadian regulations

First steps of fuselage construction

Trim Servo Mount Detail

Plastic window tracks with kerfs cut on the tablesaw

Oil cooler mount detail

Horizontal stabilizer wood strips and root junction detail

Custom cowl decoration

Left side of completed airplane

Right side

Dynon panel

Seats and cabin

More cowl detail

Exhaust mount