Charron,
You should have had the joy of using Decca in a single pilot helicopter on the North Sea! (With no RadAlt either.....but three BarAlts!)
Did anyone ever perform the Decca approach to Sumbrugh at night in cloud, single pilot, and coped with the key and map change?
Talk about something that made Lucille look like Tammy Wynette....sssshhhhh it Doc....two flakes of snow and Decca left quicker than a Rat from an aqueduct.
It's been 30 years since those fun days and I think I can still remember how to operate the Decca due to all the practice one got trying to keep the thing working.