An MD80 was level at FL340 heading north, about to descend. The controller did not detect a converging eastbound B737 and, therefore, cleared the MD80 to descend to FL300. When the MD80 started its descent, a Short Term Conflict Alert was triggered. In the attempt to rectify the error, the controller instructed the MD80 to stop the descent. Under stress, he issued a confusing instruction for the B737 to turn. The pilot did not respond. At this point, both aircraft received a coordinate RA: The MD80 received a Climb RA that he followed correctly while advising the controller. The B737 pilot received a Descend RA, which was also complied with. As a result of the coordinated Climb and Descend RAs, the two aircraft passed each other with a vertical separation of 1400 feet and a horizontal separation of 0.6 nautical miles. A simulation undertaken later showed that the vertical separation would have been only 100 feet without these maneuvers. 5. What is the vertical separation of the two aircraft when they passed each other?