PDF Publication Title:
Text from PDF Page: 046
9/8/98 AC 43.13-1B (d) Check ribs on either side of strut attach points for missing or loose rib-to-spar attach nails. (e) Check ribs on either side of strut attach points for cracks where the cap strips pass over and under the spars. (f) Check for cracked leading edge skin and/or failed nose ribs in the area directly in front of the jury strut. (g) Check the brackets which attach the struts to the spars for cracks. (h) Check the aileron, flap hinge, and hinge brackets for cracks and loose or missing rivets. (i) Check all exposed end grain wood, particularly the spar butts, for cracking or checking. Checking, or splitting, of wood spar butts is common on aircraft based in arid areas. FIGURE 1-3. Likely areas to incur structural damage. (j) Also check for any cracks that in- dicate a bond line failure or structural failure of the wood member. Any evidence of move- ment of fittings, bushings, or fasteners should be cause for concern, and further inspection is warranted. Splits in fabric covering the ply- wood, especially on upper surfaces exposed to ultraviolet light and water, dictate that the me- chanic remove the fabric around the split so the underlying plywood may be inspected for physical damage or decay. When removing metal fasteners from wood, check for evidence of corrosion. Any corrosion present indicates the presence of moisture and the strong prob- ability of decay in the adjoining wood structure. (k) Any wooden member that has been overstressed is subject to compression failure (e.g., ground loop). Compression cracking and failure of the wood spars in cer- tain aircraft are a continuing problem. Com- pression failures are defined as failure of wood fibers on a plane perpendicular to the wood fi- ber’s longitudinal axis. If undetected, com- pression failures may result in structural failure of the wing during flight. Compression cracks have been found emanating from the upper surfaces of the wing spars and progressing downward. (l) The usual locations for cracks have been the front spar at both ends of the reinforcement plate for the lift strut and the front spar rib attach points, both inboard and outboard of the spar reinforcement plate; and the rear spar lift strut and rib attach points. An inspection of both the front and rear spars for compression cracks is recommended. (m) The two areas where it is possi- ble to identify a compression crack are on the face and top surface of the spar. Using a borescope through existing inspection holes is one method of inspection. An alternate method is to cut inspection holes in the skin. If inspection holes are cut, they should be made on the aft side of the front spar and the forward side of the rear spar. This will allow the fabric to be peeled away from the spar. Longitudinal cracks may also be detected dur- ing this inspection. Loose or missing rib nails may indicate further damage and should be thoroughly investigated. The mechanic may shine a light, at a low angle and parallel with the grain, in the area of the member Par 1-29 Page 1-13PDF Image | AFS-640
PDF Search Title:
AFS-640Original File Name Searched:
ac_43.13-1b_w-chg1.pdfDIY PDF Search: Google It | Yahoo | Bing
5,000 BF Shipping Container Lumber Dry Kiln For Quality Lumber The 5,000 BF container kiln consists of one 40 foot high-cube aluminum shipping container... More Info
Shipping Container Lumber Dry Kilns by Global Energy Global Energy designed and developed the container kiln back in 1991. The purpose is to give access to portable sawmill owners, furniture makers, and small business the value added profit of dry kiln lumber and quality hardwoods... More Info
Vacuum Kiln Conversion Kit for Lumber and Wood Dry Kilns Convert your existing conventional dry kiln into a fast drying vacuum kiln. Similar to vacuum bagging in the boat building and aircraft industry, we have come up with a proprietary process which allows you to build a very simple vacuum kiln at a fraction of the price, and without the intensive conventional metal chamber structure... More Info
Vacuum Pump Cart System for Bagging Clamping Wood Drying and more Vacuum Cart with 2HP Pump and Dual Pistons with multiple multiplex vacuum ports and liquid reservoir... More Info
Vacuum Bagging Basics Vacuum bagging is a method of clamping, which has traditionally been used in the composites industry, but can also be used for vacuum drying materials, including wood products... More Info
CONTACT TEL: 608-238-6001 Email: greg@globalmicroturbine.com (Standard Web Page)