Speed as such is not a 'load'. 2.5g at 250kts and a given weight/CG is the same load on the structure as 2.5g at 150 kts and that weight/CG (those speeds chosen to eliminate compressibility effects). The loadings are defined at specific speeds so speed cannot really be also subject to a 1.5 factor.
Agreed.
Not sure what you have in mind here.
FAR 25.629 says, "....enlarged at all points by an increase of 15 percent in equivalent airspeed at both constant Mach number and constant altitude."
Basically that tells me it applies to an aircraft which is not experiencing changes in altitude and airspeed which would induce flutter at a speed lower than 1.15 Vd.
The following I posted above your last post, but you may miss it since I need to wait for mod approval....
In short, I am having a discussion with someone who feels the Loads defined in FAR 25.301, the factor of Safety in FAR 25.303, and the Strength and Deformation definitions in FAR 25.305 will provide a margin of safety for an aircraft which hypothetically would be accelerating through Vd+50 and pulling upward of 2-3.8g.
I contend no such margin exists nor is defined by Part 25.301, 303 and 305.
Thanks again for all your replies.