"This requirement was in the Australian design standards (101.5/6)"..... and also buried in the FAR design standards.
"
although it is years since we have read them"..... Shame on you
J_T
T'was 15% in the FAR Design Standards, I cannot recall whether the Australian design standards (101.5/6) differed..... Shame on me
(Particularly as the last time that I applied 15% was on an Australian registered aircraft)..... whoops.
Regards,
Old Smokey