RE: Debow
In the ITVV documentary, the SFE Roger Bricknell mentioned the selection of debow of #3 engine upon startup on the JFK to LHR leg, due to the downtime of the engine. This essentially delays the heat-up of the turbine shaft in favor of a more evenly temperature distribution.
Why wasn't the debow selected for all the other engine? (Roger explicitly mentioned to not needing to select the other engines for debow)
Forgive me, I'm probably missing something that was mentioned earlier in this great thread.