This isn't a cool feature when you are looking at flights. Say I am in the US and I book a morning flight from Beijing to Abu Dhabi, what possible reason would I want to see this in my current US time zone? It gets even worse when you book a flight that crosses over time zones, or even arrives earlier than it departed (flying from Eastern Russia into Canada).
The solution to confusing time zone switches is setting the entry as a "Floating" time zone. Then no matter where I am, I can look at that flight and know that it is set correctly.
iCal on OSX has supported floating time zones for ages. The problem with Calendar on iOS is that it forces you to select a timezone when you add an entry, there should be an option to select "Floating" just like you can on OSX.
Right now, I need to add the entry then go to my computer and edit the entry to use floating time zone.
It shouldn't be that difficult.