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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Bob’s Method for Installing the Windshield

Source: 1998 Beartracks, Bob Barrows

The windshield is fitted in place after the boot cowl is made and installed.



The windshield is held in place at the top by sliding into the windshield mounting (section T-T dwg. 16), by tabs which are welded to vertical T14 tubes at section B-P, and by a fairing and backup strip at the intersection of the windshield and the boot cowling.



NOTE: Do not remove the protective film from the windshield. Cut the windshield to fit the boot cowl using a 1/32″ thick 3″ diameter high speed cut off wheel mounted on an air die grinder. Do not attempt to cut the windshield to fit all at once. You should take off no more than 1/2″ inch at each pass.

After the proper fit is obtained hand sand smooth all edges of the windshield.

Windshield Fairing

The Fiberglass fairing is made up of about 8-10 layers of 4″ fiberglass tape, then trimmed to size and sanded smooth.

To make the fiberglass fairing at the bottom of the windshield, tape the windshield in its proper location and cover it and the boot cowl with black electrical tape. Cover the bottom 4″ of the windshield and the front 4″ of the boot cowl where it intersects the windshield. Add a good coat of wax to the taped area and lay up the cloth.

Some of you may be able to make this fairing out of 5052 aluminum. I hope that someone does.

As shown in the photo the fairing goes from the T14 tube around the front of the windshield and back to the T14 tube on the other side of the fuselage.



The back up strip of .032 5052 H32 aluminum is first bent about 110° on a brake, then stretched and shrunk as needed to match up with the windshield and boot cowl. Both the back up strip and the fairing are attached to the boot cowl using #6 screws about 3″ apart with nut plates on the boot cowl.

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