The Boeing B-52 Stratofortress has become an icon although it was the result of a difficult birth courtesy of various officials whose understanding of realistic goals was overridden by the desire to chase an impossible dream. Eventually a great eight engine high winged bomber would appear on the Seattle flight line. The first model would be a development batch with the B Model being the first operational version. From these two batches would come the famous Balls 3 and Balls 8 of NASA fame. Of all the versions of these tall tail bombers the B-52D would be the one that would achieve a certain measure of fame. Not only was this the largest production run of all the models, but it would also be the main bomber used during the Vietnam War having succeeded the B-52F in this role. Eventually the B-52D would be the only survivor remaining in service till it was replaced in the remaining Strategic Air Command Bombardment Wings by the B-52G and B-52H.