Like any business, radio has its share of unwritten rules. If you’re an on-air talent, however, your unwritten rules basically boil down to just one, and it’s inviolate: your shift has to be covered. Short of a fatal or near-fatal accident, you are expected be seated in front of the microphone at your appointed time (or have made arrangements for a suitable replacement to take your place). Even most of what would be classified as an act of God (i.e., tornado, hurricane, flood) wouldn’t qualify as a valid reason for you to miss your shift at the assigned time without a replacement. I can hear my boss now . . . “If you had enough time to flee, you had enough time to call a sub!”
In my nearly 20 years at WNUA I can recall only two instances where an on-air host didn’t show up for their shift without an explanation. (That’s significant, if you think about it: five shifts a day, 365 days a year—doing the math, that’s 36,500 shifts in 20 years, and only two were left uncovered.) Both cases, however, involved the same person, and that person ended up with one of the shortest reigns of any full-time announcer I worked with on 95.5. I am positive this wasn’t a coincidence. I also had the misfortune of doing the shift immediately before this announcer’s, and I ended up having to cover most of their shift myself both times.
That final point is the reason why this rule is so sacred. Radio stations have no one waiting in the wings to take over in a pinch. Most part-time and vacation relief announcers hold full-time jobs elsewhere. Whenever you heard a Scott Adams or Domingo Castillo filling in for someone else on WNUA, for example, realize that they had to make their own arrangements to take time off their other jobs to fill in as a substitute announcer on 95.5. They couldn’t just drop what they were doing and come in. In other words, leave your shift uncovered without a replacement, and you set off a mad scramble (and a string of frantic phone calls) on the part of your boss, the program director, a person who definitely has better things to do with their time. In my experience, that’s something the typical PD has a long memory for.
Miss a shift without explanation once, and it’s likely to end up in your personal file. Miss a shift more than once, and they’re starting to work on your severance papers. Going AWOL in radio does come with a very harsh penalty. Thankfully, in an era of cell phones, you’d really have to try hard to mess this one up.

