Just send him the money first. Everything will be fine.
Some guys haven't had the luxury as they start up to have seen the world like yourself Adroight.
Aucky, read up on Nigerian 419 scams on Google. Beware of dealing "directly" with some "reputable staff members" of Bristow or any other employment companies in Nigeria.
I would suggest you contact the required helicopter company via their official website and deal with their HR, not some individual who has a "Bristow" email address.
Good luck!