Between Mair and Buchheim the limit for attached flow will lie around 22-23 degrees of tangent angle.Anything beyond that and we'll have separation unless we provide blowing or vacuum in critical areas.
These 'steep' curvatures may have been a compromise for the life-cycle-cost analysis of the particular project.
If you have Kate Winslet in the can,you might get some extra $millions re-releasing her films in 3-D.Or is that Double-D?
If you'
re hauling freight and 115/145 AVGAS is costing you 18-cents a gallon as when I used to pump it,you may not give a d--- about a little extra drag and a mediocre boat tail.I wouldn't try and read too much into 'why' certain things got done unless you have access to the designer.
And with respect to the Packet and Flying Boxcar,a number of parachutists were injured attempting to jump with the tail in place,so they just removed it and lived with the inefficiency.
