This kind of repair, he said, resulted in a weld chemistry similar to the weld on the S-IVB helium bottle that had failed, as had only recently been determined by examination of the secondary-propulsion-system tank repair weld. There was insufficient proof that titanium hydride concentrations could not occur in the double method-2 repair weld, and replacement of the tank would preclude any question as to the integrity of the tank. The decision was delayed as long as possible in the hope of developing technical justification of weld integrity. When that was not achieved and there was little confidence that justification could be developed in the near future, the decision was made directing the tank change. The activity would not cause additional schedule time loss, as it was already necessary to repeat the spacecraft integrated test because of wiring rework.