Agreeeing with many of the coments above I woul like to add my personal opinion apologizing for my lack of command in english. One must take into consideration the swept of the 727 wing that developped a very poor stability in lower speeds. As many of you recall swept wings develop a lot of induced drag in the low speed region flight needing to increase the angle of attack in order to develop lift (and more drag). The Vref speed is very close to the minimum drag speed and any drop (of speed) induces a further increase in drag needing a lot of power or altitude to trade (sink) to regain speed.This is called the "divergence zone' and the B727 more than any other commercial jet was prone to develop more and more drag as the approach speed decay. I read in a book that the first pilots to fly the B727 used to add some extra knots on the approach speed and this was also because of the stall speed used for certification purposes that taked into account the speed during stall in lieu of the minimum speed with still leveled flight. The pilots that I flew with at that time used to joke that approach speed was "Vref plus two" where 2 means 2 fingers - figure what is two fingers on an analogic IAS... I flew some 6.000hours on the 727 (-100) either as copilot and later as a captain. I enjoyed a lot this machine and consider that it has been my jet handling school for all other aircraft that I flew since then. The combination of these handling carachteristics with the poor engine accelerationn and the lack of previous jet experience of the former captains of the 60's - early 70's probably have been the main cause of many of these accidents and the option to ban the Flaps 40 configuration landing might have been the way to deal with that. This is just my opinion, of course.