Originally Posted by
BigDaddyBoxMeal
Not seen it mentioned in the discussion so far but where I work (UK) the 737NG requirement for engine run up in cold conditions is normally mentioned to ATC by crew when reporting ready.
"Tower XXX123 ready for departure, we will require 30 seconds on the runway"
It's not a formal procedure but 3 based operators of 737s do it often to aid ATC awareness. I believe it came out of regular local ATC/operator/pilot meetings.
One should always do that if they are going to need an engine run. Some like to do it on the taxiway though. I was behind a Korean 747 one time and very quickly lots of water spray started kicking up behind him. Fortunately, we had fairly good spacing. And while decent spacing is good anytime, it seems like it is more likely on a ground icing day to encounter someone doing an engine run without advising.