1998 Control Stick Engineering Notice (376 and Below)

Source: 1998 Beartracks, Bob Barrows

Refer to drawing #26 for plans serial numbers 376 and below.

The T3 control link that works inside of the 1 1/8 X .049 torque tube does not have enough clearance to use standard attach hardware as shown in view B.

Make the link as shown below so that standard hardware can be used at the cable attach locations. A 3/16" steel rivet will be need to be used at the control stick attach point. I made the rivet by cutting a AN23 clevis bolt to the 19/32" length behind the threads.

If you have already made the link you can use the AN3 bolt at the cable end with a thin nut with Loc-Tite and or peen slightly (see photo).

Another solution would be to make the .062 end brackets at an angle such that all the hardware works outside the 1 1/8 x .049 torque tube as shown above. Plans number 376 and up have this arrangement. If you would like a new drawing #26 please send $3 to cover printing & shipping cost.

The Bearhawk I am building now will use the control stick as your plans show with the 3/16" steel rivet joint at the control stick attach point. See photo above.

You are not yet authorized to view this page. Learn more here.

1998 Wing Strut Material Update

Source: 1998 Beartracks, Bob Barrows

As mentioned in past issues of the newsletter, we have been involved in obtaining new strut material for use on your BEARHAWK project. This endeavor was initiated due to many builders request.

We have designed and purchased an extrusion die so as to produce the strut shown.

The struts are made from aluminum alloy 6061-T6 and heat treated per. spec. Our supplier has provided us with chemical and mechanical certifications for each lot ordered.

We have also designed new aluminum strut end fittings that can be bolted to the strut material. We can supply this NEW strut material and the drawings for the end fittings for shipment inside and outside the U.S.A. Contact R&B Aircraft for details.

You are not yet authorized to view this page. Learn more here.

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.

You are not yet authorized to view this page. Learn more here.

1998 Firewall Positioning Engineering Notice (326 and below)

Refer to Drawing # 18 firewall detail.

During the assembly of the Bearhawk I am now building I found that the 7 1/2" dimension was about 1" too high. This dimension should be reduced to about 6 1/2". See corrected drawing below.

This change is needed to keep a good line from the top of the nosebowl to the top of the instrument panel and increase the tunnel area at the bottom of the firewall for better engine cooling.

Please note the size of the firewall has not been changed, it has just been positioned lower on the airframe.

Also note that depending on the type of engine you use, the shape of your nosebowl and the height you make the instrument panel may affect the vertical location of the firewall.

The minimum clearance of the engine and related components to the cowl is 1/2".

You are not yet authorized to view this page. Learn more here.