Incorrect Stitching Grounds Aircraft

[old man emu]

Today at work we discovered a major fault in a Classic aircraft on the VH register that has resulted in its immediate grounding, and a possible $20,000 cost to restore the aircraft to an airworthy condition.

 

Many years ago, this aircraft had a full replacement of its fabric. It appears, from our initial inspection, that the person who stitched the fabric to the wings did not use the knot specified in the the relevant FAA (hence Australian) Standard. That knot is the Modified Seine Knot. As a result, there is a danger that, should one of the stitches come undone, the fabric in that area of the wing could separate from the wing, resulting in the loss of the wing's aerofoil shape, with the consequent loss of Lift and then control.

 

If you are involved in the construction or repair of fabric covered airframes, do you know how to tie a Modified Seine Knot? :;)3:

 

Old Man Emu