I wouldn’t say bad apple. There is just a crap ton of info to assimilate and be able to apply.

It’s about being able to get back into the command attitude and be able to make good decisions in a timely manner. Most guys that elect to return to FO say it’s the knowledge based decision making that was the sticking point.

Foreign ATC isn’t going to tell you their transition altitude is 4,000 feet instead of FL180; nor will they often tell you a speed that is already published someplace. Bad habits like saying “in the box” instead of squawk 1234 are as bad as saying Oh, instead of zero. English is their second language and things will get messed up fast. Being precise, structured, and professional goes a long way on the radio.... and in the Sim for the instructor.

In the past 6 months, I know of 3 FO’s who elected to discontinue CA upgrade and return to FO. It is a crap ton of studying and refreshing; and Then being able to apply the info in the Sim and on ground. It is a lot, but it’s also a very good, very fair program with excellent instructors.

You’re also the CA (company employee supervisor in foreign countries) when outside the cockpit, so you get to be HR for the FA’s and GSC and well everybody else too.