Thursday, March 19, 2009

Good Morning!

It’s only 8:30am and I’ve already had two "firsts".

Numero Uno

I’m working the Whiting departures this morning. Standard operation, the usual bunch of VFR Navy T-34 departures heading out into the beautiful, clear morning sky. Multi-ship flights, solos, dual trainers. Nothing out of the ordinary. The push has died down some and I have about four aircraft on my frequency.

My facility manager is standing next to me and we’re discussing how my training is going on the Pensacola bank. Things are quiet.

Due to the light traffic at that time, there are only three scopes active, one for each of our Class C airports. Each of those single scopes is responsible for all the airspace relating to its respective bank. I'm working the NSE scope.

Suddenly, the ARTS on my scope goes down. At that second I have my head turned so I don’t see it when it flicks off. My manager notices it and speaks up.

I look back. All the alpha-numerics on the scope are gone. Datablocks. Departure tab lists. Activations. They’re bye-bye, their ghosts fading into blackness. All I’ve got are my primary targets and my map. A quick glance around the room reveals that the other five scopes in the room that feed off our Whiting radar are blank as well.

Well, shit.

I immediately crank up my primaries to the max. Bright slashes glow on my scope now, each representing an aircraft. Our Whiting VFR departures are written down on traffic count sheets. I examine my targets, review the “flick” in my mind, and correlate them mentally to the call signs on my sheet. I’m not quite in “radar contact lost” territory yet. The good thing is they’re all VFR anyway and therefore ultimately responsible for their own separation.

For the non-controllers out there, here's a little before and after so you can picture what I'm seeing (or not seeing):

At least I didn't lose my entire radar. This is similar to what air traffic control used to look like, back in the day. No datablocks, no transponders, nothing. If you've got targets of some kind, you could work - if you can tell who each target is. At this point I'm considering checking Ebay for some secondhand shrimp boats.

In the meantime, one of the techs bursts in from the system room. A computer hardware swap went awry and reset the Whiting radar's hardware. It should be back up quickly. Cool. Tech knows about the issue and they’re working on it.

While he’s telling us this, our Flight Data person has called up Whiting tower and tells them to stop departures. We've already got a few birds in the air. We don't need more at the moment. Doing that gives us time to figure out the next step.

Okay, so I know who’s who, what’s wrong, and that it’s being worked on. Now what?

We have two ASR-11 radar sites in our airspace: one about 15 miles north of Whiting field, and another located directly at Pensacola Regional. The issue took out the ARTS for the Whiting radar, but the Pensacola radar is just fine. Both are redundant systems and either one can operate the entirety of our airspace.

At the moment we lost the Whiting radar feed, we were left with this:

If it had been a single Whiting scope that went down, no big deal. Scopes die like any other piece of hardware. Just slide over to another Whiting scope, key up the frequencies, and keep working.

But with the actual Whiting radar being down, it's not that simple. While we have six working scopes in the room that run off the Pensacola radar, I can’t just slide over to any scope and just pull up the frequencies. Out of our twelve total scopes, only five scopes have the required radios ("NSE" in the radio list), and four of those are unusable since they run off the Whiting radar! The remaining one is the Pensacola East sector, which is currently manned and is unaffected by the outage since it runs off the Pensacola radar.

So, the controller at the Pensacola East sector – which runs off the Pensacola radar – has now pulled up my targets and is seeing the aircraft datablocks just fine. He’s also standing by to key up the frequencies if needed. The East sector is the "mother sector" for all of the sectors in the house, so it has all frequencies for the PNS, NPA, and NSE banks available.

In short, we can see the airplanes clearly, and we can talk to them. Good. If I can’t get fully back online, all the East sector needs to do is type a keyboard command and my traffic will be combined with his.

This gives us time to enact the next phase. As part of our system redundancy, we have the ability to reset all scopes in the room to use either of the radar sites. It just takes another keyboard command to implement it. Once entered, the scopes swab over to whichever sensor is needed automatically. After that’s done, all you need to do is reset the radar maps on each scope to center them on the new radar.

Resetting the Whiting sectors to the Pensacola radar would bring us back online as such:

Luckily, as we’re about to switch sensors on the dark scopes, the Whiting radar comes back. Huzzah! After that, everything works great. No problems. Naturally, the pilots never knew anything about it.

Overall, not really a big deal. All of this took place over maybe two minutes. That’s one of the great things about redundant systems. We were back to normal in no time. Even if tech hadn’t been able to fix the original issue, once the scopes were switched to the Pensacola radar we’d have been just fine.

Even if it was a worst case scenario and the Whiting radar scopes were completely knocked out, we have options. The East controller could physically move over to the unused West sector. Since the West is the companion sector for the East, it has radios with the East frequencies. Then, the Whiting controller - a.k.a. me - could take over the East scope and just key up only the Whiting frequencies there. So, we’d have the West scope acting as the East, and the East scope acting as the Whiting, and both would be running off the Pensacola radar.

It would look like the following. It’d be strange, but it would work.

I’d never seen anything like this before. Not in training. Not ever. Unlike my flying days, where you’re constantly reviewing emergency and fire checklists, there is no checklist for this. You just have to be flexible and figure it out. After it happened, I was asking my coworkers a ton of questions about best practices for those kinds of situations.

There were several things I could have done better. For instance, I should have jumped faster on the “stop departures” call to Whiting tower to keep them from adding more to the fun. Thankfully, the experienced CPC on Flight Data took care of that.

As they say, a pilot’s license is a “license to learn.” The same thing applies to ATC certifications. There’s no better teacher than new experiences.

Numero Dos

Now for the (very) anti-climactic second "first": primary target-only radar identification using turns. Woo hoo! Same session as the radar outage too. Packed full of fun with primary targets....

A Forestry Service aircraft calls me up departing an uncontrolled field. As I'm typing in his callsign to issue a squawk, he reports that his transponder is out and he wants to land at Pensacola Regional to get it looked at. Of course, his current stated position and heading put him southbound, right in the middle of a flock of other VFR targets. He could be any one of them.

Some legalities to consider. He's a primary target only, and he wants to enter the Class C airspace containing Pensacola Regional.

The FAR's say the following:
Sec. 91.215 - ATC transponder and altitude reporting equipment and use.
(b) All airspace. Unless otherwise authorized or directed by ATC, no person may operate an aircraft in the airspace described in paragraphs (b)(1) through (b)(5) of this section, unless that aircraft is equipped with an operable coded radar beacon transponder [...] and that aircraft is equipped with automatic pressure altitude reporting equipment having a Mode C capability[...]

(1) All aircraft. In Class A, Class B, and Class C airspace areas;
Without a transponder or Mode C, he doesn't meet the standard equipment requirements for Class C.

However, the end of FAR Sec. 91.215 has an exception:
(d) ATC authorized deviations. Requests for ATC authorized deviations must be made to the ATC facility having jurisdiction over the concerned airspace within the time periods specified as follows:
(2) For operation of an aircraft with an inoperative transponder to the airport of ultimate destination, including any intermediate stops, or to proceed to a place where suitable repairs can be made or both, the request may be made at any time.
According to the rules, since he's landing at Pensacola in order to get his transponder fixed, he's allowed into Class C without prior notification.

So, how does one figure out which target he is? ATC can radar identify primary target-only aircraft via three methods, as specified by FAA Order 7110.65.
  1. Departing aircraft: Identify an aircraft within 1 mile of the runway departure end.
  2. Position correlation: The aircraft tells you where he is, and you simply look for a target there. "Approach, Cessna 123, we're five miles south of Milton airport."
  3. Identifying turns: Direct and observe an aircraft to make a turn of at least 30 degrees.
#1 wouldn't work, since he's already airborne. #2 would be feasible, if not for the eight other targets in the vicinity of his reported position. So, that leaves me with just #3.

I’d studied it a while ago, knew the phraseology, knew what to look for, but I’d just never actually done it. The 7110.65 requires a minimum of a 30 degree turn. I choose to give him a 90 degree right turn since A) it's easier to spot and B) due to his reported southbound heading and position, it would point him at Pensacola Regional, his destination.

"FFXX, this will be a turn for radar identification. Turn 90 degrees right."

All of the other targets are milling about, but I spot one making a definite sharp turn to the west, breaking out from the others. No question it's him. Our radar and ARTS can tag and track primary targets, so I type “FSXX”, slew on the primary target, and press "Enter" . It tags up with his callsign. “Radar contact."

I write up a strip, scribble "Transonder Inop" on it, and pass it on, then inform the next controller via landline that FSXX is a primary only target. Handoff. Switch. All done on my end. Not much to it. Surprisingly painless.

So that was two valuable learning experiences on the job, and both within an hour of punching in. An interesting start for what turned out to be an interesting day.


Peter S said...

Nice post. Very informative for a layman pilot. thanks.

deltamike172 said...

That's some good times right there.

Dale Kettring said...

Gee, I thought you had STARS not ARTS.

Wicked Penguin said...

Dale: Negative, not yet. Our new building (with STARS) should be finished by the Fall.

Anonymous said...

What was really fun, back in the 'who wants a transponder' days, was issuing an identifying turn and watch three or four wiseguys all make the same turn.

Anonymous said...

Try recovering those AF fast movers using British RAF primary radar only for a high tech USAF controller. That was a real hoot.