Let me clarify here a situation (and status) of a good friend of mine.
xxx
She is a lawyer from Argentina, and resides (part-time) in Coral Gables, FL.
She owns an apartment there since 1998. She does not have a "green card".
When arriving, with a regular US tourist visa, and gets admitted for 90 days.
She owns a car with Florida plates, and has a Florida driver's license.
Generally stays a few weeks, then goes to Argentina for a few days/weeks.
What is her activity...? - Lawyer. Let me explain.
xxx
She DOES NOT practice law in USA.
Advertises in Buenos Aires papers "La Nación" or "Clarín" to be a lawyer.
Her real office is in the city of Buenos Aires. An assistant answers her phone.
And her Miami phone is tied with the Buenos Aires phone lines.
She represents Argentina citizens living in the US with Argentina courts.
Most of her clients live in Florida. Some are in other US states, or Canada.
She goes to meet them, or they come to Miami to meet her.
Of course, her residence has a room which is her "office".
No advertisement in USA. Not listed in phone book, just her name+number.
Practices law in the courts of Argentina. Real estate and contract law mostly.
xxx
Despite our friend Boeing100 opinion, I think it can be well done by pilots.
I DO NOT SAY "work as pilot to/from USA base".
But call it your "second (or part-time) residence".
If you fly with your airline to USA, you hold a "D Visa" as crewmember.
But then, you need to hold a regular US Tourist Visa (no I-94W).
Both can be in your same passport. Just declare your status on arrival.
Crewmember - or "90 days I-94 tourist".
xxx
In 1998, I was often in Miami, simulator instruction. I had a US Passport.
My wife (Argentina citizen) wanted to be with me for frequent stays there.
She rented a furnished studio in Pompano Beach, and bought a used car.
I wanted her to get a "green card", "just in case"...
Stay requirements, USA tax obligations etc. made it quite complicated.
So we cancelled that idea, and continued with her "tourist status".
xxx
I know some pilots who do something as I described here above.
One in Florida, one in California. They travel in/out frequently. No questions.
And a flight attendant, lives with her boyfriend in Greenwich Village, NYC...
xxx
Happy contrails