hl1 was developed around 1997-1998, and it had ospreys as well,
the osprey existed since the 80’s and it was public knowledge. the US field trained pilots since 2000
the osprey wasnt deployed into mainstream military until 2007
but one can assume the Black Mesa incident (which i still believe to take place at 2003) was an event of great urgency, that the US had to covertly deploy their ospreys to the HECU and Black Ops before the real deployment
BMS shouldnt be set in 2007 due to the aircraft depicted (which clearly existed long before such a modern time period)
not to mention hl1 is basically a near-future alternate history
the timeline should be 2003, and the appearance of ospreys should be a sign that the US are deeply concerned about the incident at hand and are willing to deploy their new aircraft far ahead of schedule