Although Johnson was not responsible for tracking TWA Flight 800, he spoke directly with the ATC who did. In fact, he asked him “plenty of questions to prepare myself for the ‘suits’ who were beginning to arrive.” Along with several other ATCs, he viewed the radar tape of the incident. According to Johnson, “A primary radar return (ASR-9) indicated vertical movement intersecting TWA 800.”
An advanced radar system, the Northrop Grumman ASR-9 is able to detect a “target” in severe clutter even when the target has no transponder. The absence of a transponder is what distinguishes a “primary radar return” from a “secondary” one. In others words, the radar picked up a small, unidentified, ascending object intersecting TWA 800 in the second before the 747 “disappeared from radar.”
After Johnson and his supervisor watched the video tape replay with audio, they turned to each other and said in unison, “What the f***!" Asked by his supervisor if he had ever seen anything like this before, Johnson said yes -- while in the Navy days doing missile test fires at sea.
A day later, now knowing the full scope of the tragedy, Johnson asked if he could take another look at the radar tape. “Can’t, it’s gone,” said his supervisor. “We had better say nothing,” said Johnson, “or the f***ing government will make us disappear.” The supervisor agreed.