Also see:  
 http://www.forbes.com/sites/johngoglia/2013/07/12/if-drug-and-alcohol-testing-for-asiana-flight-214-crew-not-required-by-law-why-didnt-ntsb-or-faa-request-voluntary-compliance/
 http://thehill.com/blogs/transportation-report/aviation/310151-ntsb-chief-asiana-pilots-were-not-drug-tested
 http://www.upi.com/Top_News/US/2013/07/09/Asiana-flight-crew-not-tested-for-drugs-or-alcohol/UPI-24951373351400/
 http://www.ibtimes.com/asiana-airlines-flight-214-ntsb-says-pilots-not-tested-drugs-or-alcohol-after-crash-1339295
 http://www.latimes.com/news/opinion/opinion-la/la-ol-asiana-airlines-drug-test-20130709,0,40181.story