flew the 8,and later the 727(both for 10yrs)the dc8 didn't sweep the wing as far back as Boeing,so it had (with the aforementioned slots-with flap extension)acceptable "slow speed"(approach)characteristics.Boeing develped the"07"originally for the USAF as a tanker(kc135)needing the higher speed wing-requirering the Led's(slats/flaps) for approach handling.Cruise of M.80+ to 135k approach.This successful concept was carried over to the "27"(providing it with some 4000 airports in the US).with the call for flaps15,one recieved 48% of wing dissasembly..Both the DC8 and the B727 were excellent aircraft.The 27 as a pilots aircraft(even on one engine)the Eight as the last economic trans ocean aircraft(the 63' burn't 11000lbs/hr for 200pax at M82)