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!

Engineering Notice Concerning Flap and Aileron Nose Skin Rivet Size (395 and Below)

Source: 1999 Beartracks, Bob Barrows

Reference plans number 395 and below, Drawings #9 and #10. The 3/32" stainless steel pull rivets holding the nose skins to the nose ribs have been changed to 1/8" aluminum pull rivets. The cost and availability of 3/32" S.S. rivets has become a problem. If you have already assembled the ailerons and flaps with the S.S. you can leave them in, they do a good job.

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1999 Engineering Notice Regarding Upper Front Door Hinge Positioning (416 and below)

Engineering Notices

Source: 1999 Beartracks, Bob Barrows

Reference plans number 416 and below, Drawing #16. As shown in the drawing below change the 5 1/2" dimension to 5 3/4" to increase clearance between door frame and bottom of the wing in the open position. If the fuselage is already welded up, adjust hinge location for needed clearance.