Forever Thank Me Later Drake

I know G4 pilots on a first-name basis

drake is saying that he is on G4 planes so much (probably because he's so rich and famous), he knows the pilots on a first-name basis
He is saying that he has so much money that he knows the pilots to private jets very well.
a Gulfstream is a very expensive private jet. G4's are one of the most expensive ones. to give a comparison, G4 is the same in the private jet world as a Rolls Royce is in the car world. def a balla to fly in em!
A "G4 pilot" flies a G4 plane. A G4 plane is a small private plane. The G stands for Gulfstream (the company that makes the plane.) The 4 is the model number of plane (ie: G450).
A G4 is an old gulfstream, more like a pre owned lex than a Rolls Royce. cheap to buy (12million) compared to a G450 (45 mill)which is new, but the mack dad is a G550, (50+mil). Pilots are just pimped bus drivers