B2N2,
i don't disagree with your comments, no its not the examiners task to check the visa; yes, as a pilot you have to deal with legal stuff, yes you need visas for some holiday destinations.
In most scenarios legal interpretation requires you to get a visa. (and I stated that in my previous post - one is definitely on the safe side). When someone asks - do I need a visa - apart from the legal answer it helps to share experiences about the whole process. I wish someone along the way would have said - I want to check your visa now as you are a flight student - that would have made me feel like the hassle getting this thing was worthwhile.
There is the cost element (see below) but there is also opportunity cost for people that work.
To actually break down the visa costs / time requirements (this varies by country + exchange rate though)
cost of getting US embassy appointment in the first place $10 (2 weeks beforehand offpeak, 1-2months beforehand peak i.e. when lots of students apply for them)
Visa fee: ~$150 (depends on local currency)
SEVIS fee to register (necessary): $200
other small stuff - like getting passport sized photograph the way the US embassy wants it (which is unfortunately not the way the EU wants it. nobodys fault but still annoying). paying secure insured delivery for passport.....
time requirement to compile all information to fill out visa documents: 1/2 day
time at US embassy: 1/2 day - day. (if you live in a city that has an embassy / consulate else add travel)