It’s all supposed to be done the same, but it often isn’t. Worse, nobody seems to be able to say how the differences came about or why the old ways are still in place.

I’ll give you an example. In nearly every airport, when an airline crew is ready for push-back, they call the ramp tower, if there is one, or they call ground control and advise they are ready for push. Ramp or ground then makes sure the area is clear and grants permission for the push-back to begin, possibly following with a specific disconnect point. It’s pretty straightforward.

A few airports have their own way of doing things that are not immediately obvious. Boston (BOS), for example, requires a crew to call clearance delivery with the ATIS code and the assigned transponder code—even if the same controller just read the clearance and the assigned transponder code to the crew. If you try to call ground, you will be sent to clearance delivery, but not for a clearance. Worse, do you know what clearance delivery will do? He or she will tell you to monitor ground control, and then lean over to the ground controller and say, “Hey, this one is ready.”

Other airports use what is called a metering frequency, but this one makes a bit more sense. Think of metering as an intermediate buffer between the ramp and ground. O’Hare (ORD) is a great example. Ramp control issues the push and immediate taxi clearances. The crew then moves to a designated spot, where they call metering. Metering then verifies that the crew has the right transponder code (the transponder will be on), and tells the crew to monitor ground. However, during bad weather, metering can pass on to the crew that they need to go to clearance for a new route, or pass on other information that will avoid cluttering up the ground controller’s frequency, such as runway changes, et cetera. Used properly, metering frequencies are one of the FAA’s better inventions, and some airports that don’t have one should get one (I’m looking at you, LGA).

Some airports don’t have controlled ramps, and crews are responsible for pushing back on their own with the marshallers and the tug drivers ensuring that the ramp is clear. Orlando (MCO) does this for some terminals, while others have a ramp control, so there are odd differences even at one airport. What is frustrating is that some of this information is either not published, or was published so long ago that nobody knows where, or worse, it’s sometimes published incorrectly by an airline in its internal manuals. It’s become institutional knowledge, and controllers tend to think that every pilot has been to their field every day.

Most of the time, the standardization efforts made by the industry are honored and they work. But like secret local traffic patterns, some airports continue to defy convention. Pay attention out there!—Chip Wright