Although the 727 was fully exonerated, training reforms associated with handling the jet during the approach phase were introduced by all operating airlines
Not 'fully'. Boeing had used aluminium fuel pipes in the 727-100 to minimise weight, and for simplicity had routed them through the base of the ventral fairing. This made them very vulnerable to damage and splitting in a crash or wheels-up landing, with resulting fire spreading from the centre fuselage. The high proportion of fatalities in the on-land crashes were mainly attributed to such inescapable fires.
The fuel system was redesigned and an AD was issued for retrofit.