Wednesday, June 17, 2009

Fun with Landlines

We use two main kinds of landlines to communicate with other facilities: shout lines and ring lines.

A shout line works like it sounds. You key up another facility - let's say, our tower - and your voice immediately gets "shouted" out over a loudspeaker in the other facility. They're typically used for positions that require extensive coordination and rapid response times, since you can immediately start talking. The other facility then picks up the line.

Say I take the handoff on Cessna 123 from Jacksonville Center. They switch the aircraft to me and he comes over requesting a descent. He's still 5 miles inside Jax's airspace so I can't descend him without their approval. I call up Jax's Crestview Low sector and say, "Crestview Low, Pensacola West, ApReq (approval request)." They hear that come over the speakers on their end. Then the Crestview Low controller - or his D-side - answers me. "Crestview low." I then say, "Request control for lower, Cessna 123." They make sure it works for them, then say, "Cessna 123, your control, [operating initials]." I say my initials, unkey the landline, and then tell the Cessna, "Cessna 123, descend and maintain [altitude]."

Ring lines actually ring like a telephone line on the other end and you can't speak until the other side picks up the line. They're used for lower intensity positions like Flight Data, where time and action aren't always critical.

Here's the thing: I'm not 100% sure on the shout lines, but the ring lines are essentially regular phone lines. They have actual telephone numbers associated with them by the phone company.

Let's look at the phone company for a second. When a customer cancels a line, that number gets sent back into the phone company's pool of available numbers. When the FAA asks the phone company for phone lines for its facilities, the phone company dips into that pool of numbers and gives the FAA however many numbers it asked for.

However, the FAA has no idea who was using those numbers beforehand...

Getting Religion

One afternoon, I'm working Flight Data. The line from a local control tower rings. I pick it up, answering, "Pensacola Flight Data."

"Hi, yes! Is this Brownsville Baptist?"

"Uh, no. This is-"

"I'm looking for Pastor Larry. Is Pastor Larry there?"

"No sir, this is Pensacola-"

"But I'm looking for Pastor Larry. I need to speak with him. I was wondering if-"

"Sir, you have the wrong number."

"But I really need to speak with him. Can you tell me-"

"Sir, again, you have the wrong number."

"Oh? Are you sure Pastor Larry's not there?"

"I'm sure he's not here, sir. You have the wrong number."

"Oh, well sorry about that. God bless!"

"You too, sir."



Well, apparently that ring line's particular number used to belong to Brownsville Baptist Church of Pensacola, FL. Maybe they moved. I don't know. Whatever the case, they cancelled a phone line, the number got recycled, and it wound up in the FAA's hands when the FAA setup their landlines. But somewhere, somehow, there are plenty of people out there who think it still belongs to BBC.

Those kind of exchanges happen at least a couple of times a month, although it was the first time it happened to me. I'm always so tempted to just "run with it" but I feel bad about doing it. Others have different ways of handling them.

For instance, there was the time a coworker here got a call very similar to the one I just described. "I'm sorry," he said, "Pastor Larry's not here at the moment. I'm new here, but let me see if I can find his number for you."

And... he proceeded to give the caller another controller's cell phone number.

A minute later, we hear a cell phone go off in the break room.

Confused hilarity ensued. :)


Dave said...

This is frickin funny.

Fred said...

I wondered, do you know the phraseology a class D tower needs to release an IFR flight to center?


Wicked Penguin said...

@Fred: I don't work tower and all of our airports are Class C's. When our towers request release, they call us over a shoutline as follows:

Tower Local Controller: "Local, East"
East: "East"
Tower LC: "Request release Delta 1281."

Let me pause right here. Our Letters of Agreement specify headings for our departures.

* Jets typically come off runway heading.
* Props have a range of 20 degrees left/right of the runway heading. For instance, if we're departing runway 35 and the aircraft's route is to the northeast, the tower can release them heading 010. If they are going west, they can put them on a 330 heading.

Ok, unpause. Unless I have a specific reason to assign a different heading, I just let the tower assign the heading as per the above LOA rules.

So, I'd say...

East: "Delta 1281, released, [operating initials]."
Tower: "[operating initials]"

If I needed to assign a heading - for instance to remain clear of traffic - I could say, "Delta 1281, heading 050, released, [operating initials]."

Anything is possible with coordination.

Fred said...

Wonderful, WP thanks. Just what I needed to know for VATSIM use.


Dave said...

Hi Fred
I'm a center controller at Albuquerque ARTCC, though I have no tower controlled airports in my airspace (SW specialty, PHX/TUS). They all lie within TRACONs. The NW specialty has two (PRC/FLG), both of which do not have automatic releases and have to call for release. I believe all they say when they call is to request release on the aircraft callsign, to which the controller will either say released, hold for release (usually for traffic or TMU), or released (and give alternate instructions to comply with new traffic situations). These areas are very mountainous, so headings are rarely used, at least until the aircraft gets above the MIA.

Fred said...

Hi Dave,

Thanks for that.


Bart said...

In my area at ZME we have had a fax machine call the dial line we have to one of the VFR towers in our airspace. It always gets everyone's attention when someone has routed that line over the loudspeaker and you hear the loud squeal of a fax machine trying to make a connection instead of a voice.