Ref: WAF Modification
The drawings indicate that the UK mod is actually lighter than the R-R
WAFs. Each individual WAF fitting is made from 2 thicknesses of .063
steel (as opposed to one of .125 for the R-R). One is slightly longer
than the R-R fitting and one is considerably shorter. The long fitting
has 4 extra AN4 bolts running down the center instead of the 3 (so
called) lightening holes--the shorter fitting is a doubler at the wing
attach bolt and catches 2 of the extra bolts and four of the standard
bolts. There are four 3/8 inch alum bushings in the spar for these extra
bolts.
I have heard of WAFs loosening over time. Would putting the 3
bushed bolts down the center of a R-R WAF rather than the large graduated
lightening holes be an improvement? I do understand that there is an
engineering reason for the large holes. Comments from engineering
types??
Dick Hartwig
Waunakee, WI
rhartwi...@juno.com