Installing Aileron and Flap Hinges

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Updates from Bob, 2021 Q2

There have been two recent safety updates. The first was a minor drafting error in the flap hinge, which impacted the Model B 4-Place, Patrol, Companion and Five, and was distributed in April. This photo shows the revision:

There is also a new update released 6/28/2021, which will also show up at bearhawksafety.com in the coming days. This is an Engineering Change that relates to the way the covering is tucked into the channel at the top of the windshield.
Bob’s instructions are, “Fabric attachment at top of fuselage to windshield mounting frame channel- A few aircraft have had fabric come loose. As shown is a good way to glue in place.”

If your fuselage is already covered and isn’t routed as shown in the update, he says, “If it has been flying for a while, it should be fine, but it is something that we need to let people know about.” Bob also brings up the point that it’s crucial to follow the instructions of the covering system that the builder selects. Popular systems including Polyfiber, Stewarts, and Oratex vary greatly with crucial details. In a recent case, reinforcing tapes were able to peel up with fingernail intervention, which prompts Bob to bring up that point.
Bob and Mike have been busy building engines, trying to reduce the lead time which has grown long due to strong demand.
His Bearhawk LSA is back to flying status, thanks to builder Collin Campbell in Missouri. Bob flew the airplane home and was pleased to report it flies straight after the extensive rebuild. Some of the original engine parts fly again in the new plane.

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Flap Hinge Mounts: Tack Weld At First

Source: 1999 Beartracks, Bob Barrows

Refer to drawing #13. When making the flap hinge mounts it is best to just tack weld the pieces together first and not finish weld until the wing is finished and the flaps are in place. This will allow you to cut the tack welds and realign the hinge mounts if needed in order to achieve the best fit up between the flaps and wing. Once the fits are established then remove the fittings from the wing and finish welding.


Flap hinge mount as removed from welding jig, tack welded together only!

1998 Inboard Flap Lever Engineering Notice (280 and below)

Source: 1998 Beartracks, Bob Barrows

Reference drawings #12 and #14 for plans serial numbers 280 or below.

Inboard Flap Lever

The inboard flap lever arm was shortened from 4-1/8" to 4" for clearance with the aileron cable. If you have completed this assembly you may remove up to 1/16" from the tip of the flap lever arm for clearance.

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