The building of Winch Drum #4 should have appeared in Soaring Dec. 2013 or Jan or Feb. 2014.

Send me a private e-mail and I'll send you a .pdf of the proof copy.

After the three failures, the little bit good, Mo Betta, approach was used on #4. We had a stress analysis model to work with, but without knowing what the actual stresses are, the model didn't do us much good. So you take what was done on #3 that almost worked, and just do everything a little bit better. Probably overkill, but no one wanted to build #5, or to have to admit to four failures.

SF