TASK DEFINITION: Classify the relation of question with context to one of these categories: 1) award received, 2) based on, collection, 3) conflict, 4) constellation, 5) convicted of, 6) date of death, 7) director, 8) drafted by, 9) educated at, 10) medical condition, 11) military branch, 12) narrative location, 13) occupation, 14) original network, 15) parent company, 16) point in time, 17) production company, 18) residence, 19) series, 20) service entry, 21) sex or gender, 22) spouse, 23) standards body question.
PROBLEM: Context : June 1942, the Aichi H9A was employed in a variety of second-line roles, including anti-submarine missions along the Japanese coasts, transport, paratroop training and liaison. 
Question : What was the year that Aichi H9A entered service?

SOLUTION: service entry

PROBLEM: Context : Niourk (published 1957) is a science fiction novel by the French writer Stefan Wul. 
Question : Which place is Niourk in?

SOLUTION: narrative location

PROBLEM: Context : Bad Machinery started on 21 September 2009 loosely based on characters and situations from John Allison's previous webcomic, Scary Go Round. 
Question : Which place does Bad Machinery exist in?

SOLUTION:
narrative location