Temporal agent Phillip Martin was needed, but they didn't have time, to sent the standard way of time travel. Or give the proper tools send with him, and he was expert of the early 1930's to 1960's. To stop a temporal paradox, or to put it simply to create a alternate time line. So they had to transpose his conscious into a person that era. To temporarily be that person.The good news/ bad news that person could be someone insignificant to allowed to be unnoticed that time period. When he was send to stop the disaster.
What worse to him, he was transposed into a body of woman. Which was worse, he hated to be transposed into a woman's body. Specially he was in the body of air stewardess, of that time. They had to be perfect, they look perfect, dress perfect, act correctly.
They always have look right. This was the problem, he always hated the fact that was in a woman's body. It always felt wrong, to him, it felt something was to tight, or it didn't fit right. But he looked perfect was a air stewardess. And he had pretend to be her. Plus find and stop the disaster. While acting perfect.
And he has barely one hour to do before they create alternated timeline.