Start here: http://www.faa.gov/licenses_certificates/airmen_certification/foreign_license_verification/
Also what's the purpose of this conversion? Does he intend to work for a U.S. operation? He would need a Green Card or EAD (Employment Authorization Document) to be employable in the States. Also forget about work visa, he's not gonna get it for a pilot job, that has nothing to do with FAA, but rather with USCIS and DOL.
Sure he'll get a work Visa. All he needs is a sponsor. It happens all the time for pilot jobs, from all kinds of different countries.
No he won't. He has exactly zero chances of getting a work visa via sponsorship. His only chance is to be otherwise eligible (e.g. via family ties) for a EAD or GC.
Pilot jobs are not eligible for H1B visa since no 4-year degree or equivalent experience is required. H2 specifically lists eligible occupations and pilots are not on the list. L1 is reserved for intracompany transfers and executives (I don't believe there's a Mexican carrier with hub in the US). I won't discuss more exotic visa categories (religious workers, personal servants, work&travel, postdocs etc). There's simply no visa class for pilots in the U.S. under current immigration law.
Tell that to a particular company that hires Greeks out of Van Nuys then. I worked with two guys that were here on work Visa's. Both of them from Greece.
Edit to add: All they both needed to start working was tax ID numbers. Neither of them when hired had green cards. There was also a guy from the middle east working there at the time. He had been with the company for a while, and had gotten his citizenship while working there.
He was born in Mexico. And is here in America on a Tourist Visa at the moment. So he needs a work visa to go through this process?
Tax ID alone is not a sufficient proof of employment eligibility, see form I-9 and instructions (it is required for anyone employed in the US) The tax ID is only needed to set up employees payroll and benefits.
Unless you personally checked their immigration records in USCIS computer you cannot assert whether they had or had not a green card. It doesn't have to be a piece of plastic, it can also be stamped in the passport or even be a letter sized printout.
PS: Not saying it didn't happen but if that happened it was illegal and you should have reported them to the ICE.
Had a chance to talk to one of the guys. I asked him how he's stayed with the company/in the country for so long. He came here on a temporary visa to get his certificates as a "student Visa" that was good for a year. He had to get it extended to finish his certificates because he hadn't finished them on time. While here for his certificates he needed to work and was able to add that on. When he finished, he started working as a First Officer and the company sponsored him. It was all legal, all legit. He said his first Visa was nothing more than a stamp in his passport, so he carried it around with him everywhere because he was afraid he would be asked for it. After that, it was some paper work he was issued. He now has his green card, so he is a legal full fledged citizen. When I asked him how he got his citizenship, he explained to me the test he had to take, and I couldn't even answer some of the questions he had to about US history. It took him almost 7 years from setting foot on American soil to Green Card.
If he has a green card he's not a US Citizen. If it's found out that he's been claiming himself as a citizen on forms for employment, if and when he applies for citizenship he will probably be denied naturalization. USCIS are picky.
JESUS! I don't know the guys life story. Want me to give you guys his freakin number and you can give him the third degree about how he lives!!!!