Ground Communications Outlet (GCO)

[John_Mitchell]

I've recently noticed that some airports have a Ground Communications Outlet (GCO) frequency. I looked through all of my training books, etc...but could not find exactly what this frequency is for. Is it some sort of way to make a phone call from the air??

 

[zmiller4]

I've recently noticed that some airports have a Ground Communications Outlet (GCO) frequency. I looked through all of my training books, etc...but could not find exactly what this frequency is for. Is it some sort of way to make a phone call from the air??

Yup...you dial up the frequency, key the mike a certain number of times (four? is that standard?) and it hooks you up on a phone line to the appropriate ATC facility.

 

[TFaudree_ERAU]

Its a relay to the local approach or center facility. It is used by IFR aircraft to pick up their clearance on the ground when normal air to ground VHF comms can't be established. The advantages to the GCO over the normal method of picking up the clearance on the phone is that the pilot can be sitting at the end of the runway ready to go as soon as the controller can work his release. Disadvantages can include an unreliable connection to the controller, as I believe most GCOs will disconnect you if there are no transmissions for 30 seconds or so. This means you have to click the PTT switch every so often to keep the line open.

 

[launchpad]

I've only seen one work...tried a few of them too......the details are buried somewhere in the AIM section dealing with communications....