Agreed Jonesy . I had just assumed that all acft had it. Serves me right for assuming!
Could it be more a 2 eng Vs 4 eng structural thing in that an over weight landing with fuel in the wings PLUS the weight of those extra two engines outboard will be more likely to overstress the spra/wing box should one accomplish a less than smooth touchdown... God help us..?
But then Lancer just said some 76s can dump... so i'm grasping at straws here.
So far;
For:
Herc, B767, Electra
Against:
B737, B767