Just for context I’m currently sitting at about 250~ hours and applying to airlines back in South America. I did my training in the USA, therefore I have my instrument rating, MEL rating, and Commercial pilot certificate, from the FAA. I converted them back to be able to apply, so all good there.
Is there any chance I can come back to the US with more hours, as all aircraft are “N” registered, and be able to apply for a Job in the USA? If so, what are those options?
If I understand your question correctly, you received a Commercial Pilot Certificate, Instrument Rating, and Multi-engine Land rating issued by the FAA under 14 CFR Part 61. You want to know if flight time you acquire in South America in an "N" numbered airplane (an aircraft of U.S. registry), after having received FAA issued certificate/ratings in the U.S., can be logged and counted as flight time in accordance with FAA regulations?
The regulation below (14 CFR 61.51 (j) (a)(1)) states that you can count and log that flight time, as long as the aircraft involved have either a standard or special airworthiness certificate . Applying for a job in the U.S., with respect to a company's flight time requirements (logged in accordance with 14 CFR 61.51), should not be an issue.
I don't know what you mean in the last part of your question - "If so what can those options be."
(a) Aircraft requirements for logging flight time. For a person to log flight time, the time must be acquired in an aircraft that is identified as an aircraft under § 61.5(b), and is—
(1) An aircraft of U.S. registry with either a standard or special airworthiness certificate;
(2)[...]
(3)[...]
(4)[...]
(link to 14 CFR 61.5(b) above is mine)
FAA certificates do not expire.
You will need a work visa and a company that will sponsor the work visa.
You will need an FAA ATP certificate after you have 1500 hours in registered aircraft. The aircraft do not need to be registered in the USA with N-number, but they cannot be ultralight. If a company is willing to sponsor the visa then they will also organize the ATP certificate tests.
It will be much easier to find a job if you first have an ATP in your home state. This is proof of ability before they spend money to get you an FAA ATP.
