When I was a youngster I flew the Straight-Pipe and CFM powered DC-8's in the front seats at ATI, then rode side-saddle on them at UPS as a junior employee. One of the performance changes was VMCG for the CFM powered variants over the JT-powered aircraft due to the same standard tail surface being used through out. Power reductions where watched closer in the JT powered birds as an abrupt tug to idle could result in some impressive cabin pressure bumps or even a rapid-D event due to those aircraft still having turbo-compressors as pressurization devices. The double rotation maneuver was taught more as a check to see if your engineer had provided the correct V-speeds from the many charts measured with a micrometer, then hacked out with an axe, and the characteristic of the Douglasaurus having a very pitch sensitive manual trim-tab flying tail which could easily result in an over-rotation, or your destruction in severe turbulence. The saving grace of the DC-8 was its over-built Fuselage and DC-direct cable simple manual systems. The wing slats helped improve the tendency for the airplane to fly a nose-low approach. The wing was very advanced for its time and efficient, to include wing tip fuel tanks which decreased drag and moved the CG aft in flight. The DC-8 was a great airplane with an impressive service record. But it's true what they say, Boeing builds good airplanes, while Douglas builds better pilots.
