At the risk of boring everyone to distraction I have a couple of new
points to make.

I've been watching this evening the repeat Tx on Ch4 of the programme
where they took an RAF crew and trained them on a simulator to repeat
the Dams' raid.
As part of their training they were taken to Canada and flown on a
Lancaster for experience. I noticed that all the crew, including the
Canadian pilot, were using open microphones. That is, no oxygen mask,
just a boom mic which appeared to have a tapering funnel from near the
mouth to a mic insert near one earphone.
Engine noise was audible but the speech was perfectly clear.
Agreed that the Lancaster was unloaded concerning fuel, bomb load, guns
and ammunition, etc, so that the engines were not working so hard there
was no trouble in following the conversations.

Mike
--
M.J.Powell