JT, zzuf, Clan, et al, interesting views.
zzuf, 'Limit is shown by …'; actually its demonstrated for certification (playing with words - the manufacturer shows that the requirement is met).
However, the lowly flight-crew have no indication, no show and tell, no instrument or tech description; thus take it easy as JT #29.
zzuf, Back to #20, or without load indication, not knowing doesn't matter because you can't get there #30 ?
Clandestino, we are facing the same direction.
However, is your application the 0.666 factor to the AFM 'normal g' limit a precaution because the pilot has no indication (good practical advice), or a real limit to be respected ?
Three Wire, re A4; as I recall a high 'g' pull up with asymmetric slats (one hangs up - not enough grease) resulted in significant rolling 'g'. There was a video of a TA4J shedding a large drop tank.