Here is an article relating to the last PanAm flight out of Saigon Airport April 1975. What a story! Pan American World Airways
There are also some good newsclips on the ITN channel of YouTube relating to this period of the war. Wish more news agencies would add clips like that to YouTube.
I watched this on Netflix a couple of years ago and really enjoyed it. Last Days in Vietnam: 2014 American documentary film written, produced and directed by Rory Kennedy During the chaotic final weeks of the Vietnam War, the North Vietnamese Army closes in on Saigon as the panicked South Vietnamese people desperately attempt to escape. On the ground, American soldiers and diplomats confront the same moral quandary: whether to obey White House orders to evacuate U.S. citizens only—or to risk punishment and save the lives of as many South Vietnamese citizens as they can. The events recounted in the film mainly center on the US evacuation of Saigon codenamed Operation Frequent Wind. Interviews with some of the last U.S. man on the ground--the chaps on the embassy roof--and some of those non-combatants who got out in the nick of time.
I watched "Last Days in Vietnam" back in August of 2015. I had to change the TV channel when the last group of Vietnamese waiting for a rescue helicopter were never picked up.