Hull loss accident statistics resulted in the FAA mandating that an apprentice pilot (i.e. A bare commercial license with a meager 150 hours) is not permitted to set foot in any US regulated commercial jet.
From the linked article:
"Major U.S. carriers long have relied on hiring pilots who already have the required minimum of 1,500 flight hours, typically amassed in military aircraft or by working as a civilian instructor before snagging a job at a regional airline. Breaking with that tradition, JetBlue borrowed from training regimens used by the military and some carriers in Asia and Europe to create the Gateway Select program, which seeks to train pilots “from the beginning.”
.......and then build up 1,500 hours of flying experience before they are hired at JetBlue."
Jet Blue's program is four years long and the candidate accumulates 1500 hours of flying experience at completion....and before setting foot in a Jet Blue aircraft.
Vastly superior than what the Asian and Middle Eastern airlines are currently getting away with.
US carriers would not allow one crew member to be an apprentice second officer...never mind allowing two of them on a long haul crew! No matter how much money this would save.