In 1987 dan rather stormed off the set of CBS evening news so viewers were treated to seven minutes dead air why was upset?

That's not quite right. While Dan Rather did walk off the set of the CBS Evening News in 1987, it was not because of "dead air".

Here's what actually happened:

* The incident occurred on October 9, 1987. Rather was angered by a decision made by CBS News management to preempt a planned segment about the Iran-Contra affair with a report on the stock market crash.

* Rather felt the stock market crash was not a more important story than the ongoing Iran-Contra scandal. He believed the preemption was a political decision, driven by the desire to appease Wall Street.

* He walked off the set in protest. Rather's actions were captured by the camera, and his anger was evident.

* The segment on the Iran-Contra affair was eventually aired later in the broadcast.

While Rather's outburst didn't lead to "dead air," it did cause a significant stir within CBS News and was widely discussed in the media. It was a stark example of the tension between journalists and management, and the sometimes competing priorities of news coverage.