Conversation so far:
What kind of jobs did Chesley Sullenberger have in aviation?
Chesley Sullenberger was employed by US Airways and its predecessor airlines from 1980 until 2010.
When did Chesley Sullenberger found Safety Reliability Methods?
In 2007, Chesley Sullenberger became the founder and CEO of Safety Reliability Methods, Inc.
What kind of company was the organization Safety Reliability Methods?
Safety Reliability Methods, Inc., is a firm providing strategic and tactical guidance to enhance organizational safety, performance, and reliability.
Does Chesley Sullenberger still work for the company Safety Reliability Methods?
Chesley Sullenberger retired in 2010.
Did Chesley Sullenberger have any other jobs in his civil aviation career, besides working for US Airways and Safety Reliability Methods?
Chesley Sullenberger served as an instructor, Air Line Pilots Association Local Air Safety Chairman, accident investigator, and national technical committee member.

Question: When did Sullenberger serve as an instructor?
Self-contained rewrite: When did Chesley Sullenberger serve as an instructor?