From the YouTube description:
In the early 1960s, the BBC spoke to almost 300 people about their experiences during the First World War for landmark series The Great War, but only a fraction of the interviews were broadcast. This programme airs a selection of the original material, most of which has never been screened before, with recollections of the horrors of artillery bombardment and fleeting outbreaks of peace on the battlefield, as well as the stories of those on the home front waiting for news of their loved ones.



P.S. For some reason it has still screen shot has nothing to do with the doco.

This website Timeless voices' has a page with the 56th FG pilots. Fantastic interviews, McCauley, Kyler, Rankin et al.
Check it out
http://www.eaa.org/timelessvoices/