Did they leave the RadAlts?
In the UK sector we used three BarAlts and no RadAlt on the 58T's....which while flying in the Ekofisk was interesting as the Norwegians used RadAlt heights not MSL for traffic separation.
Why ever would one actually want to know one's height above the sea when one had the Regional QNH to rely upon!
Then there was the legendary Bristow attitude towards GPS in Nigeria.
"No Thank You....Yank DOD Thingy that!".
Then...the Nigerian CAA mandated all Nigerian registered aircraft would have GPS. Then it was "Fine...but when they go U/S...we are not going to repair/replace them as the Reg only says installed and not that they be functional!".
God...I wish I was making this stuff up!